I. INTRODUCTION

Welcome to Save Our wild Salmon’s Hot Water Report 2021. During the summer, this weekly report is providing updates on real-time water temperatures in the lower Snake and Columbia river reservoirs via graphs and analyses, reports on the highest weekly water temperature at the forebay/reservoir of each dam, and the status of adult returns for different salmon and steelhead populations as they make their way back to their natal spawning grounds. We’ll share information from scientists, fishers, guides, advocates, and other experts about the challenges facing the Columbia and Snake rivers - and opportunities we have to restore healthy rivers and to recover abundant fish populations and the many benefits they deliver to the Northwest’s culture, economy, and ecology.

The once-abundant anadromous native fish populations that call the Columbia-Snake River Basin home are struggling to survive primarily due to multiple harmful effects caused by the system of federal dams and their reservoirs. The federal hydro-system creates conditions that harm and kill both juvenile and adult fish, including by elevating water temperatures in large, stagnant reservoirs, especially in the summer months. As cold water species, salmon and steelhead begin to suffer harmful effects when water temperatures exceed 68° Fahrenheit. The longer and higher temperatures rise above 68°F, the greater the harm, including disruption in their migration, increased metabolism, increased susceptibility to disease, reduced fecundity or reproductive potential (by reducing egg viability), suffocation, and in the worst case - death.

These harmful hot water episodes above 68 degrees in the Columbia and Snake rivers are increasing in duration, frequency, and intensity. Our changing climate is making an already bad situation for the Northwest’s emblematic fish worse. Our region and nation must take urgent action to cool these waters or we will lose these species forever. Restoring a freely flowing lower Snake River by removing its four federal dams is our best and very likely only option for lowering water temperatures in this 140-mile stretch of river in southeast Washington State. Restoring the Snake River is one essential part of what must be a larger regional strategy to protect and rebuild healthy, abundant salmon and steelhead populations in order to benefit other fish and wildlife populations, including critically endangered Southern Resident orcas, to honor tribal rights, and to ensure prosperous communities across the Northwest.

Will you be on the river this summer? Do you have a story or photo you would like to share? Please send them to Martha Campos

The Hot Water Report is a joint project of the Save Our wild Salmon Coalition, Washington Sierra Club, Columbia Riverkeeper, Idaho Rivers United, National Wildlife Federation, Snake River Waterkeeper, Northwest Steelheaders, Defenders of Wildlife, and Endangered Species Coalition.

II. READING THE DATA - Lower Snake and Columbia River Temperatures

The daily mean temperature at the four reservoir forebays (immediately upstream from the dam) in the lower Snake River (above) and the lower Columbia River (below) for 2021 is represented with solid lines and their 10-year average (2011-2021) temperatures with dashed lines of the same color. The dotted horizontal line across the graph represents the 68°F “harm threshold” for adult and juvenile fish. Salmon and steelhead begin to suffer harmful effects when water temperatures exceed 68° Fahrenheit. The longer temperatures remain above 68°F and the higher the temperatures rise above 68°F, the more severe the potential effects. Water temperatures remain high - and harmful - to salmon and steelhead in the lower Snake and lower Columbia River reservoirs: On the lower Snake River, the waters in all four reservoirs have exceeded the threshold (68 degrees) this week. The Ice Harbor Dam has consistently maintained mean temperatures above 68°F, and with a high mean temperature of 71.24°F on July 28, July 29, and August 3. The Lower Granite Dam had high mean temperatures of 71.24°F on August 3.

On the lower Columbia River, current reservoir temperatures are above the 10-year averages for this time of the year, and all reservoirs registered temperatures above 70°F. On August 3, 2021, the John Day reservoir had the highest mean temperature of 73.22°F. This week, the Bonneville reservoir had the second highest mean temperature of 72.86°F.

A note on the lower Snake River Water Temperature Graph: The mean water temperature data from these reports comes from the USGS Current Conditions for Washington State and the 10-year average water temperature data comes from the Fish Passage Center. USGS began recording water temperatures at Ice Harbor and Lower Monumental on June 16, 2021, Little Goose on June 19, 2021, and Lower Granite on June 18, 2021. Although we are not able to compare spring water temperatures to summer water temperatures, we can see June temperatures rising above the 10-year average and all water temperatures in the lower Snake River are above 60°F.

III. WEEKLY HIGH TEMPERATURES: 7/28-8/3

On the lower Snake River, all reservoirs registered high temperatures above 68°F for multiple days. This week, the reservoir behind Ice Harbor Dam registered the highest temperature at 72.14°F - significantly above the level that coldwater fish require. Lower Granite Dam had the second highest temperature at 71.96°F.

On the lower Columbia River, all reservoirs registered high temperatures above 70°F for multiple days. The reservoir behind the John Day Dam had the highest temperature this week at 73.58°F, followed closely by the rest of the dams with a high temperature of 73.04°F

Temperature data included in these reports come from the USGS Current Conditions for Washington State and the Fish Passage Center. Graphs and tables were assembled by SOS Staff.

 IV. A Look at Snake River Wild Salmon & Steelhead Returns

This week, we have a special addition to the Hot Water Report focusing in on the current status of imperiled Snake River salmon and steelhead populations. This article was contributed by Stephen Pfeiffer, Conservation Associate at Idaho Rivers United - an SOS member organization based in Boise, ID.

The Snake River's anadromous fish populations are continue to teeter on the brink of extinction. These salmon and steelhead face multiple obstacles, including intolerably hot water in the summer months in the Snake River reservoirs. Below, we present background information on and current status of native fish returns, including (1) wild Snake River Spring/Summer Chinook, (2) wild steelhead, and (3) wild/natural sockeye. We will also look at how the current numbers of returning adults compare to established recovery goals - the adults returns deemed necessary to recover these populations and remove them from the Endangered Species Act list.

What Are Wild Salmon and Steelhead Returns?
The size and condition of a given population of salmon or steelhead is determined by the number of adult fish that return from the ocean to their upriver spawning grounds each year. The most straightforward method to measure the size of a salmon run is to count the fish as they pass upstream. These counts today occur at the dams themselves.

Snake River salmon and steelhead runs are counted at Lower Granite Dam, the last impediment on the river before the fish enter hundreds of miles of tributary spawning and rearing habitat in central Idaho and eastern Oregon, and southeast Washington State. Returning salmon have been counted at the farthest upstream dam on the lower Snake River since Ice Harbor Dam was first completed in 1962. This dataset of 60+ years, coupled with informed estimates of run sizes before the dams were constructed, provides valuable insight into the precipitous declines wild salmon and steelhead have experienced in the last 4-5 decades.

Historical Context
The dire situation Snake River wild salmon face can be lost on the public when a return increases from one year to the next. Enthusiasm about an uptick in returns in a given year is a symptom of the “shifting baseline syndrome” where the perception of what constitutes a healthy population is based only on recent reference points. These benchmarks are very low already as a result of population declines that have steadily worsened across decades. The result is that our collective perception of what constitutes a healthy salmon run continually shifting downward. Put simply, the Snake River Basin historically (before the dams) produced many millions of returning adult salmon and steelhead. It produced nearly half of all the spring chinook that returned annually to the Columbia Basin overall. Notably, Columbia-Snake River spring chinook are very important to hungry Southern Resident orcas because they have been available as large, numerous and fat-rich prey in Northwest coastal waters during winter months when few other fish are.

Recovery Goals: Informed By the Past, Potential for the Future
High end recovery goals for wild Snake River salmon and steelhead have been set to reflect the healthy runs that returned to Idaho in the 1950s. The goals represent self-sustaining, harvestable populations that currently available, high quality habitat in the Snake River Basin could support. Restoring abundant populations will allow salmon to once again function as keystone species, feeding countless animals and plants, and supporting Northwesterners' cultures and economies. Restoring the lower Snake River through dam removal is our very best river and salmon restoration opportunity anywhere in the nation today. Scientists predict it can regularly produce more than a million adult salmon and steelhead entering the mouth of the Columbia River in the spring and summer months.

Current Status of Snake River Returns
Wild Snake River chinook as well as sockeye and steelhead, are much closer to extinction than recovery. In 2020, just 8,556 wild spring/summer Chinook returned to Idaho. Compared to the 4,152 wild Chinook that returned in 2019, this may seem like a strong improvement and a sign of a population on the right track. However, the oscillating nature of salmon returns means that variation from one year to the next is normal. The recovery goal for wild spring/summer chinook calls for a 10-year average of 127,000 returning fish. Notably, the 2020 adult return is less than 7% of this recovery target and the 10 year average is just 11% of that target. We have a long way to go to recover these stocks and it will require some big changes to accomplish it.

8,287 wild steelhead returned to Idaho during the 2018-2019 run, just 8% of returns from the 1950s. The recovery goal for steelhead is 104,500 returning fish annually. The 10 year average for steelhead is 28,911, which is 28% of the recovery goal.

Hot Water Impacts
The hot, dry conditions of summer 2021 are forecast to become increasingly the norm due to climate change. Periods of prolonged hot water in the Columbia-Snake River reservoirs are lethal to these coldwater species returning to the Snake River. Hot water particularly impacts sockeye which migrate upstream during peak heat in July and August.

The 10 year average for sockeye returning to the Stanley Basin in central Idaho is just 94 fish, 1% of the recovery goal. This year, the fish aren’t even being given the chance to return to spawning grounds in central Idaho's mountain lakes. Idaho Fish and Game is trapping the sockeye that arrive at Lower Granite Dam and hauling them by truck to an Idaho fish hatchery as a precautionary conservation measure.

Hot water this year is jeopardizing the existence of this already very fragile sockeye run. Last week, video footage and images showed sockeye with large, open lesions and fungus caused by hot water conditions from the lower Snake and lower Columbia River reservoirs. Restoring the lower Snake River will significantly help to address many of the problems that these fish face today - hot water, a slowed current, increased predator populations, increased susceptibility to disease, and increased juvenile salmon migration times. Restoring this historic salmon river is essential for protecting these fish from extinction and rebuilding the many benefits they provide for the people of the Northwest and our nation.

LINKS TO RECENT NEWS:

• Columbia Riverkeeper: Yakama Nation, Environmental Groups Hold Vigil to Highlight Salmon Die-offs, Need for Lower Four Snake River Dam Removal (July 30, 2021)
• Columbia Insight: As salmon cook in rivers, pressure on Biden mounts (July 29, 2021)
• NRDC: Sockeye Salmon Dying, Temperatures Rises on Snake River Dams (July 28, 2021)
• New York Times: Rising river temperatures are stressing out salmon in the Pacific Northwest (July, 2021)

 Martha Campos is the Hot Water Report Coordinator with Save Our wild Salmon this summer while she resides on Kizh/Tongva ancestral lands in California. Martha holds a BA from the University of California, Davis in Native American Studies (and two minors: Environmental Policy, Analysis, and Planning and Climate Science and Policy) and is a queer, non-binary person of color with ancestral roots in Mexico.

I. INTRODUCTION

Welcome to Save Our wild Salmon’s Hot Water Report 2021. During the summer, this weekly report will provide an update on real-time water temperatures in the lower Snake and Columbia river reservoirs via graphs and analyses, a report on the highest weekly water temperature at the forebay/reservoir of each dam, and the status of adult returns for the different salmon and steelhead populations as they make their way back to their natal spawning grounds. We’ll share information from scientists, fishers, guides, advocates, and other experts about the challenges facing the Columbia and Snake rivers - and opportunities we have to restore healthy rivers and to recover abundant fish populations and the many benefits they deliver to the Northwest’s culture, economy, and ecology.

The once-abundant anadromous native fish populations that call the Columbia-Snake River Basin home are struggling to survive primarily due to multiple harmful effects caused by the system of federal dams and their reservoirs. The federal hydro-system creates conditions that harm and kill both juvenile and adult fish, including by elevating water temperatures in the large, stagnant reservoirs, especially in the summer months. As cold water species, these salmon and steelhead begin to suffer harmful effects when water temperatures exceed 68° Fahrenheit. The longer and higher temperatures rise above 68°F, the greater the harm, including disruption in their migration, increased metabolism, increased susceptibility to disease, reduced fecundity or reproductive potential (by reducing egg viability), and in the worst case - death.

These harmful hot water episodes above 68 degrees in the Columbia and Snake Rivers are increasing in duration, frequency, and intensity. Our changing climate is making a very bad situation for the Northwest’s iconic fish worse. Our region and nation must take urgent action to lower these high temperatures - or scientists tell us that we will lose these species forever. Restoring a freely flowing lower Snake River by removing its four federal dams is our best and very likely only option for lowering water temperatures in this 140-mile stretch of river in southeast Washington State. Restoring the Snake River is one essential part of what must be a larger regional strategy to protect and rebuild healthy, abundant salmon and steelhead populations in order to benefit other fish and wildlife populations, including critically endangered Southern Resident orcas, to honor tribal rights, and to ensure prosperous communities across the Northwest.

Will you be on the river this summer? Do you have a story or photo you would like to share? Please send them to Martha Campos

The Hot Water Report is a joint project of the Save Our wild Salmon Coalition, Washington Sierra Club, Columbia Riverkeeper, Idaho Rivers United, National Wildlife Federation, Snake River Waterkeeper, Northwest Steelheaders, Defenders of Wildlife, and Endangered Species Coalition.

II. READING THE DATA - Lower Snake and Columbia River Temperatures

The daily mean temperature at the four reservoir forebays (immediately upstream from the dam) in the lower Snake River (above) and the lower Columbia River (below) for 2021 is represented with solid lines and their 10-year average (2011-2021) temperatures with dashed lines of the same color. The dotted line across the graph represents the 68°F “harm threshold” for adult and juvenile fish. Salmon and steelhead begin to suffer harmful effects when water temperatures exceed 68° Fahrenheit. The longer temperatures remain above 68°F and the higher the temperatures rise above 68°F, the more severe the potential effects, including: increased metabolism, increased susceptibility to disease, reduced fecundity or reproductive potential, and/or death.

Water temperatures remain high on the lower Snake and lower Columbia River reservoirs: Once again this week, all reservoirs exceed the 10-year average for this time of the year. Throughout this week on the lower Snake River, Ice Harbor’s reservoir has consistently maintained mean temperatures above 71°F, and with a high mean temperature of 71.96°F on July 10, 2021. The Lower Monumental Dam had high mean temperatures of 70.52°F.

On the lower Columbia River, current reservoir temperatures are significantly above the 10-year average for this time of the year, and all reservoirs registered temperatures above 68°F. The Dalles Dam and the John Day Dam had the highest mean temperature of 71.06°F, and the Bonneville Dam had the second highest mean temperature of 70.88°F.

A note on the lower Snake River Water Temperature Graph: The mean water temperature data from these reports comes from the USGS Current Conditions for Washington State and the 10-year average water temperature data comes from the Fish Passage Center. USGS began recording water temperatures at Ice Harbor and Lower Monumental on June 16, 2021, Little Goose on June 19, 2021, and Lower Granite on June 18, 2021. Although we are not able to compare spring water temperatures to summer water temperatures, we can see June temperatures rising above the 10-year average and all water temperatures in the lower Snake River are above 60°F.

III. WEEKLY HIGH TEMPERATURES: 7/7-7/13

On the lower Snake River this week, all reservoirs registered high temperatures above 68°F for multiple days. Ice Harbor Dam reservoir registered the highest temperature at 72.32°F - significantly above the level that coldwater fish require. Little Goose and Lower Monumental Dams had the second highest temperature at 71.06°F.

On the lower Columbia River, all reservoirs registered high temperatures above 69°F for multiple days. The Dalles and the John Day Dams had the highest temperature this week at 71.42°F, followed closely by the Bonneville Dam with a high temperature of 71.24°F.

Temperature data included in these reports come from the USGS Current Conditions for Washington State and the Fish Passage Center. Graphs and tables were assembled by SOS Staff.

IV. Nez Perce Tribe’s “Snake Basin Chinook and Steelhead Quasi-Extinction Threshold” Analysis

Since time immemorial, the Nez Perce Tribe, also recognized as the Nimiipuu people, have been “connected to the lands and waters of modern-day Idaho, Washington, Oregon, and Montana long before the creation of the Nez Perce Reservation.”¹ As a sovereign nation within the United States, the Nez Perce Tribe retains the “inherent right to fish at usual and accustomed fishing stations, and hunt, gather, and graze livestock on open and unclaimed lands, all outside of the reservation boundary.”¹ However, due to “colonial encroachment, dam construction, and non-tribal fishing,” the numbers of traditional fishing sites for the Nez Perce Tribe and the number of fish have declined.² The Nez Perce Tribe’s Department of Fisheries Resources Management is a critical program that protects and enhances fishing rights reserved by the Tribe in its treaties with the United States.³ Notably, the Department of Fisheries Resources Management successfully managed to bring back Snake River Fall chinook from the brink of extinction, re-established coho salmon, once extirpated from the Snake River Basin, and has become one of the largest and most successful tribal fisheries programs in the United States.³

Earlier this year, the Department of Fisheries Resources Management presented their analysis called “Snake Basin Chinook and Steelhead Quasi-Extinction Threshold Alarm and Call to Action.” The analysis indicates that nearly half of the wild spring chinook populations in the Snake River Basin have crossed a critical threshold known as the Quasi-Extinction Threshold (QET), signaling they are nearing extinction and without intervention, many may not persist. In addition, the river’s steelhead populations also face alarming threats to their continued existence.

To understand what Quasi-Extinction Threshold (QET) means, the department outlined several definitions including: QET means 50 or fewer spawners on the spawning grounds for 4 consecutive years, and the QET also signifies that adult salmon abundance in a population nearing absolute extinction and the probability of recovery is low without substantial intervention.⁴ During the ‘Salmon Orca Summit’ in July 2021, Dave Johnson, Manager of the Nez Perce Tribe’s Department of Fisheries Resources Management, presented this analysis and stated, “Quasi-Extinction means, aside from biological terminology, you are running out of options. When you have fewer than 50 fish on spawning grounds, the genetic diversity is really limited. Your ability to pull these fish out of inbreeding depression and other stochastic type risks is really limited. Any type of environmental hazard can cause havoc when you have fish populations that are so low. We are certainly running out of management options.”⁵

The analysis starts with a bar graph depicting the management goals and thresholds for the Snake River chinook salmon and Snake River steelhead returns. The desired goal for a harvestable and healthy wild chinook salmon population is 179,000.⁴ The minimum abundance for wild chinook salmon is 29,250, and the critical threshold, also known as the Quasi-Extinction Threshold (QET) is 1,850 wild chinook.⁴ Desired steelhead numbers are 137,480, followed with 20,000 as minimum abundance, and a QET of 1,200.⁴

The graphs also share the yearly forecast returns for wild Snake River chinook salmon and steelhead, which for the Snake River steelhead, the 2020-2021 forecast is 14,450 wild steelhead. The Snake River wild chinook salmon’s 2021 forecast is 8,150, but the actual returns so far this summer are only around 6,000 wild fish.^4,5

For the spring and summer chinook populations, the graph above reflects the numbers of spawners in all 31 populations listed under the Endangered Species Act in the Snake River Basin. The department modeled the natural-origin spawner abundance estimates for Snake River Basin populations relative to the QET (dash line meaning 4 years below 50 fish) for the last 10-years (2011-2020).⁴ The dots on the graph signifies how many spawners were on the spawning grounds in that year.⁵ The red dots indicate that there were 50 or fewer spawners, but more importantly, the red title for that population indicates that there have been 50 or fewer natural origin spawners on the spawning grounds for four consecutive years.⁵ During the last four consecutive years, 13 (42%) of the 31 populations had more than 4 years of abundances below the QET.⁴

Similar to the analysis above, for the Summer Steelhead populations, these graphs reflect the numbers of spawners in all 16 populations, for which there was data, of the 25 listed under the Endangered Species Act in the Snake River Basin. The department modeled the natural-origin spawner abundance estimates for Snake River Basin populations relative to the QET for the last 10-years (2011-2020).⁴ During the last four consecutive years, 3 (19%) of the 16 populations had more than 4 years of abundances below the QET.⁴

Using the current trends, the department created a model to forecast future population levels for both Snake River spring and summer chinook salmon and Snake River summer steelhead. The department “found that the chinook salmon populations are declining about 19% each year, and it is predicted that by 2025, 77% of spring and summer chinook populations in the Snake River Basin are predicted to be at or below the Quasi-Extinction threshold in the Snake River Basin” stated Dave Johnson.⁵ The model clearly shows that 77% of the natural-origin spring and summer chinook populations in the Snake River Basin will be closer to extinction within the next 5 years.

The department also found that the summer steelhead populations are declining by approximately 18% each year and predictions show that by 2025, 7 (44%) summer steelhead populations are predicted to drop below 50 spawners within the next 5 years.⁴

The Snake and Columbia River Basin contains the best available habitat for salmon populations to recover to any significant level of abundance. However, with predictions pushing the populations below 50 spawners, the four Snake River dams are a major factor preventing salmon from reaching spawning grounds. They also kill significant numbers of juvenile (smolts) and adult fish, as the dam’s reservoirs create large, stagnant pools that absorb heat from the sun, reaching lethal temperatures for salmon. Notably, they also support large populations of predatory fish such as bass and pikeminnow that eat out-migrating smolts.

In his presentation at last week’s ‘Salmon Orca Summit,’ Dave Johnson stated, “We are going through some big problems now. It’s been 100 plus degrees in the Snake River Basin. There are really hot temperatures, and the flows are down to 60% of what they should be, so it’s very hot and dry conditions out there for the fish. And with the stochastic risks, the demographic risks that fish face right now, you got one bad year like this...you don’t have any fish left.”⁵

The department ends its analysis with a series of recommended actions, including “improving survival at multiple life stages needed and seeking actions sufficient to address the current crisis and help salmon thrive,” such as the Rep. Simpson’s Columbia Basin Initiative.⁴

For more information about Rep. Simpson’s Columbia Basin Initiative and the regional conversation that he’s triggered with it, please visit SOS’ Urgency and Opportunity Resource Page.

References:
1. Nez Perce Tribe History: Traditional Ways and Treaties
2. Nez Perce Tribe: Cultural Resource Program
3. Nez Perce Tribe: Fisheries Resources Management: DFRM-Management-Plan-2013-2028.pdf (nezperce.org)
4. Snake Basin Chinook and Steelhead Quasi-Extinction Threshold Alarm and Call to Action(2021)
5. Salmon and Orca Summit 2021(July 8, 2021)

LINKS TO RECENT NEWS:

• Seattle Times: Historic summit of tribes across Pacific Northwest presses dam removal on Inslee, Biden, Congress (July 9, 2021)
• The New York Times: Like in ‘Postapocalyptic Movies’: Heat Wave Killed Marine Wildlife en Masse (July 9, 2021)
• Lewiston Morning Tribune: Tribes call for action on salmon, dams (July 8, 2021)
• NW Public Broadcasting: ‘The Very Essence Of Our Being’: Northwest Tribes (And Politicians) Gather To Discuss Future Of Salmon (July 8, 2021)
• Spokesman-Review: Washington Gov. Jay Inslee says dam breaching must ‘remain on the table,’ benefits of four Lower Snake River dams replaceable (July 8, 2021)
• Spokesman-Review: ‘Don’t give up on this’: At summit, tribal leaders urge action on dams to give salmon ‘the right to exist’ (July 7, 2021)
• Seattle Times: Record heat, drought threaten even the toughest survivors: L25, the oldest orca, and the winter Chinook she depends on (July 7, 2021)
• The Affiliated Tribes of Northwest Indians of the United States Resolution(May 2021)

 Martha Campos is the Hot Water Report Coordinator with Save Our wild Salmon this summer while she resides on Kizh/Tongva ancestral lands in California. Martha holds a BA from the University of California, Davis in Native American Studies (and two minors: Environmental Policy, Analysis, and Planning and Climate Science and Policy) and is a queer, non-binary person of color with ancestral roots in Mexico.

I. INTRODUCTION

Welcome to Save Our wild Salmon’s Hot Water Report 2021. During the summer, this weekly report will provide an update on real-time water temperatures in the lower Snake and Columbia river reservoirs via graphs and analyses, a report on the highest weekly water temperature at the forebay/reservoir of each dam, and the status of adult returns for the different salmon and steelhead populations as they make their way back to their natal spawning grounds. We’ll share information from scientists, fishers, guides, advocates, and other experts about the challenges facing the Columbia and Snake rivers - and opportunities we have to restore healthy rivers and to recover abundant fish populations and the many benefits they deliver to the Northwest’s culture, economy, and ecology.

The once-abundant anadromous native fish populations that call the Columbia-Snake River Basin home are struggling to survive primarily due to multiple harmful effects caused by the system of federal dams and their reservoirs. The federal hydro-system creates conditions that harm and kill both juvenile and adult fish, including by elevating water temperatures in the large, stagnant reservoirs, especially in the summer months. As cold water species, these salmon and steelhead begin to suffer harmful effects when water temperatures exceed 68° Fahrenheit. The longer and higher temperatures rise above 68°F, the greater the harm, including disruption in their migration, increased metabolism, increased susceptibility to disease, reduced fecundity or reproductive potential (by reducing egg viability), and in the worst case - death.

These harmful hot water episodes above 68 degrees in the Columbia and Snake Rivers are increasing in duration, frequency, and intensity. Our changing climate is making a very bad situation for the Northwest’s iconic fish worse. Our region and nation must take urgent action to lower these high temperatures - or scientists tell us that we will lose these species forever. Restoring a freely flowing lower Snake River by removing its four federal dams is our best and very likely only option for lowering water temperatures in this 140-mile stretch of river in southeast Washington State. Restoring the Snake River is one essential part of what must be a larger regional strategy to protect and rebuild healthy, abundant salmon and steelhead populations in order to benefit other fish and wildlife populations, including critically endangered Southern Resident orcas, to honor tribal rights, and to ensure prosperous communities across the Northwest.

Will you be on the river this summer? Do you have a story or photo you would like to share? Please send them to Martha Campos

The Hot Water Report is a joint project of the Save Our wild Salmon Coalition, Washington Sierra Club, Columbia Riverkeeper, Idaho Rivers United, National Wildlife Federation, Snake River Waterkeeper, Northwest Steelheaders, Defenders of Wildlife, and Endangered Species Coalition.

II. READING THE DATA - Lower Snake and Columbia River Temperatures

The daily mean temperature at the four reservoir forebays (immediately upstream from the dam) in the lower Snake River (above) and the lower Columbia River (below) for 2021 is represented with solid lines and their 10-year average (2011-2021) temperatures with dashed lines of the same color. The dotted line across the graph represents the 68°F “harm threshold” for adult and juvenile fish. Salmon and steelhead begin to suffer harmful effects when water temperatures exceed 68° Fahrenheit. The longer temperatures remain above 68°F and the higher the temperatures rise above 68°F, the more severe the potential effects, including: increased metabolism, increased susceptibility to disease, reduced fecundity or reproductive potential, and/or death.

Water temperatures remain high - and harmful to salmon and steelhead - in the lower Snake and lower Columbia River reservoirs: On the lower Snake River, the Ice Harbor, Lower Monumental, and Little Goose reservoirs have all peaked over the threshold (68 degrees) this week. The Ice Harbor Dam has consistently maintained mean temperatures above 71°F, and with a high mean temperature of 72.32°F on July 18, 2021. The Lower Monumental Dam had high mean temperatures of 71.06°F on July 17, 2021. This week, the Lower Granite reservoir is the only one with water temperatures below the 68°F threshold. Temperatures in Lower Granite’s reservoir in the summer months are typically slightly cooler than the three downstream reservoirs on the lower Snake because the U.S. Army Corps of Engineers traditionally releases cold water from the Dworshak Dam (just upstream into the Clearwater River) in July and August. However, this year, due to the extreme heatwave in the Pacific Northwest, the Army Corps began to release “43-degree Fahrenheit (6-degree Celsius) water from Dworshak Dam on June 22. These releases are continuing in July and are helping to prevent the water temperature from reaching 68 degrees Fahrenheit in the Lower Granite Dam reservoir near Lewiston (ID) and Clarkston (WA). Despite these cold water releases from Dworshak reservoir this summer, all reservoirs downstream from Lower Granite Dam continue to experience temperatures above 68°F. As long as these four dams remain in place, the benefits of Dworshak’s cold flows are limited and serve only as a short-term solution to cooling water behind Lower Granite Dam. EPA models show that a freely flowing lower Snake would carry these cooler waters all the way downstream to its confluence with the Columbia River near the Tri-Cities (WA) (see Issue 2 for more information).

On the lower Columbia River, current reservoir temperatures are above the 10-year averages for this time of the year, and all reservoirs registered temperatures above 69°F. On July 19, 2021, The Dalles Dam had the highest mean temperature of 71.96°F. From July 17 to July 20, the John Day Dam had the second highest mean temperature of 71.60°F.

A note on the lower Snake River Water Temperature Graph: The mean water temperature data from these reports comes from the USGS Current Conditions for Washington State and the 10-year average water temperature data comes from the Fish Passage Center. USGS began recording water temperatures at Ice Harbor and Lower Monumental on June 16, 2021, Little Goose on June 19, 2021, and Lower Granite on June 18, 2021. Although we are not able to compare spring water temperatures to summer water temperatures, we can see June temperatures rising above the 10-year average and all water temperatures in the lower Snake River are above 60°F.

III. WEEKLY HIGH TEMPERATURES: 7/14-7/20

On the lower Snake River this week, the reservoir behind Ice Harbor Dam registered the highest temperature at 73.22°F - significantly above the level that coldwater fish require. Lower Monumental Dam had the second highest temperature at 71.42°F.

On the lower Columbia River, all reservoirs registered high temperatures above 69°F for multiple days. The Dalles Dam had the highest temperature this week at 72.32°F, followed closely by the John Day Dam with a high temperature of 71.96°F.

Temperature data included in these reports come from the USGS Current Conditions for Washington State and the Fish Passage Center. Graphs and tables were assembled by SOS Staff.

IV. Columbia-Snake fish need help! Salmon and fishing groups, State of Oregon and Nez Perce Tribe call on court to help critically endangered salmon and steelhead.

On July 16, 2021, Earthjustice representing the National Wildlife Federation, American Rivers, Idaho Rivers United, Institute for Fisheries Resources, NW Energy Coalition, Northwest Sportfishing Industry Association, Pacific Coast Federation of Fishermen’s Associations, Sierra Club, Columbia Riverkeeper, Idaho Conservation League, and Fly Fishers International as plaintiffs, requested a motion for a preliminary injunction against the U.S. Army Corps of Engineers to address violations of the Endangered Species Act.¹ The plaintiffs are asking the U.S. District Court in Portland to order the federal dam agencies to implment specific changes (i.e. "injunctive relief") to how the dams are managed and operated starting in 2022 in order to “reduce irreparable harm to, and increase the survival of, Endangered Species Act-listed salmon and steelhead in the Columbia and Snake Rivers.”¹

This latest round of litigation is challenging the Trump Administration’s 2020 Record of Decision for Columbia River dam operations and the U.S. Army Corps of Engineers’ reliance on the 2020 Biological Opinion (Federal Salmon Plan) for the Federal Columbia River Power System.¹ The State of Oregon has also filed a similar motion for injunctive relief and with the support of the Nez Perce Tribe.²

To “reduce irreparable harm” to salmon and steelhead, the plaintiffs are asking the Court to require the Army Corps of Engineers to:

1. increase spring spill for 24 hours per day to the maximum level that meets but does not exceed state water quality standards at the dams on the lower Columbia and lower Snake Rivers, beginning in 2022;
2. restore summer spill at all eight dams to the levels set in prior BiOps (or federal salmon plans)  through August 31st, beginning in 2022;
3. provide continuous 24-hour spill from September 1 to the beginning of the following spring spill season at all eight projects through the operation of at least one spillway weir or other surface passage route, beginning in 2022;
4. operate the four lower Snake River reservoirs at lower levels, (also known as "drawdown" or minimum operating pool elevations) from March 1 through August 31, beginning in 2022; and,
5. develop and submit to the Court by September 1, 2022, an implementation plan to operate the four lower Columbia River reservoirs (above McNary, John Day, The Dalles, and Bonneville dams) at their minimum operating pool elevations from March 1 through June 15, beginning in 2023.”¹

In summary, conservation and fishing plaintiffs seek increased spill starting next spring (2022) to help endangered salmon and steelhead populations navigate the federal dams and reservoirs in the lower Columbia and Snake rivers.² Spill sends water and fish over the tops of dams - rather than through power turbines or dam bypass systems that increase fish mortality. Years of scientific study demonstrate that spill increases the survival of out-migrating juvenile fish, reduces mortality, and leads to increased adult returns in the years that follow.

Similarly, restoring spill during the entire summer migration season will help to “preserve as much of the diversity of summer migrating juveniles as possible, limit harm to them, and increase their resilience in the future.”¹ The voluntary spill from September 1 to the beginning of the following spring spill season will support the migration of late and early juveniles and serve benefits to Endangered Species Act-listed adult steelhead in the Columbia and Snake River basins that otherwise experienced harm by the limited spill.1

The plaintiffs also seek “drawdown” (lowered reservoir levels) to help speed fish migration through reservoirs with hot water temperatures. Science confirms that lowering reservoir levels “increases the speed with which water moves through the reservoirs.”¹ A faster current reduces the amount of time required for juvenile salmon to pass through the reservoirs and can also reduce water temperatures in these reservoirs to some extent, and increases the survival rates for endangered juvenile salmon and steelhead.¹ The faster juvenile salmon and steelhead pass through a reservoir, the greater the chance to avoid predators like bass and pikeminnow, whose populations have increased significantly due to the large warm, stagnant waters created by the dams.

For Snake River fish that must pass through eight dams and reservoirs to get to and from the ocean, spill and the lowered reservoir levels has the potential to significantly increase survival rates. As we have seen, temporary and short-term solutions like the release of “43-degree Fahrenheit (6-degree Celsius) water at Dworshak Dam” has helped to prevent the water temperature from reaching 68 degrees Fahrenheit and higher. Specifically, this week, we have seen consistent temperatures of 66°F - 67°F at the Lower Granite Dam’s reservoir.

Unfortunately, despite the release of cool waters from the Dworshak reservoir, harmful water temperatures have reached the Columbia and Snake Basin, with high water temperatures of 73.04°F at the Little Goose reservoir on June 27th and a high temperature of 72.32°F at the Ice Harbor reservoir on July 10th. This week, on July 18th, the fish experienced another high temperature at the Ice Harbor reservoir of 73.22°F, which hot water temperatures severely impacts the survivability of these fish. Each year, approximately 50-70 percent of young Snake River fish are killed in the dams and reservoirs en route to the Pacific Ocean.

Spill and reservoir drawdown are two methods that help aid the migration of endangered salmon and steelhead and increase their survival in the near-term. However, the best available science strongly supports lower Snake River dam removal as necessary to protect these populations from extinction and restore them to abundance. The plaintiffs view the requested injunction as “an emergency stop-gap measure and not enough alone to prevent extinction.”² A reservoir-free lower Snake River will deliver considerably cooler waters, restored spawning and rearing and migrating habitats - and big benefits to migrating juvenile and adult salmon and steelhead populations that will lead to increased survival and reproductive success.

References:
1. NWF’s Motion For A Preliminary Injunction And Memorandum In Support: National Wildlife Federation, Et Al. v. National Marine Fisheries Service, Et Al.
2. Earthjustice: With Snake River Salmon Facing Deadly Heatwave, Conservation & Fishing Groups Seek More Spill from Dams to Aid Fish (July, 16, 2021)

LINKS TO RECENT NEWS:

• AP News: Lawsuit seeks more spill over Columbia Basin dams for salmon (July 16, 2021)
• Idaho Statesman: If dams go, then what? Saving salmon, power grid means finding answers now, leaders say (July 16, 2021)

 Martha Campos is the Hot Water Report Coordinator with Save Our wild Salmon this summer while she resides on Kizh/Tongva ancestral lands in California. Martha holds a BA from the University of California, Davis in Native American Studies (and two minors: Environmental Policy, Analysis, and Planning and Climate Science and Policy) and is a queer, non-binary person of color with ancestral roots in Mexico.

I. INTRODUCTION

Welcome to Save Our wild Salmon’s Hot Water Report 2021. During the summer, this weekly report is providing updates on real-time water temperatures in the lower Snake and Columbia river reservoirs via graphs and analyses, reports on the highest weekly water temperature at the forebay/reservoir of each dam, and the status of adult returns for different salmon and steelhead populations as they make their way back to their natal spawning grounds. We’ll share information from scientists, fishers, guides, advocates, and other experts about the challenges facing the Columbia and Snake rivers - and opportunities we have to restore healthy rivers and to recover abundant fish populations and the many benefits they deliver to the Northwest’s culture, economy, and ecology.

The once-abundant anadromous native fish populations that call the Columbia-Snake River Basin home are struggling to survive primarily due to multiple harmful effects caused by the system of federal dams and their reservoirs. The federal hydro-system creates conditions that harm and kill both juvenile and adult fish, including by elevating water temperatures in large, stagnant reservoirs, especially in the summer months. As cold water species, salmon and steelhead begin to suffer harmful effects when water temperatures exceed 68° Fahrenheit. The longer and higher temperatures rise above 68°F, the greater the harm, including disruption in their migration, increased metabolism, increased susceptibility to disease, reduced fecundity or reproductive potential (by reducing egg viability), suffocation, and in the worst case - death.

These harmful hot water episodes above 68 degrees in the Columbia and Snake rivers are increasing in duration, frequency, and intensity. Our changing climate is making an already bad situation for the Northwest’s emblematic fish worse. Our region and nation must take urgent action to cool these waters or we will lose these species forever. Restoring a freely flowing lower Snake River by removing its four federal dams is our best and very likely only option for lowering water temperatures in this 140-mile stretch of river in southeast Washington State. Restoring the Snake River is one essential part of what must be a larger regional strategy to protect and rebuild healthy, abundant salmon and steelhead populations in order to benefit other fish and wildlife populations, including critically endangered Southern Resident orcas, to honor tribal rights, and to ensure prosperous communities across the Northwest.

Will you be on the river this summer? Do you have a story or photo you would like to share? Please send them to Martha Campos

The Hot Water Report is a joint project of the Save Our wild Salmon Coalition, Washington Sierra Club, Columbia Riverkeeper, Idaho Rivers United, National Wildlife Federation, Snake River Waterkeeper, Northwest Steelheaders, Defenders of Wildlife, and Endangered Species Coalition.

II. READING THE DATA - Lower Snake and Columbia River Temperatures

The daily mean temperature at the four reservoir forebays (immediately upstream from the dam) in the lower Snake River (above) and the lower Columbia River (below) for 2021 is represented with solid lines and their 10-year average (2011-2021) temperatures with dashed lines of the same color. The dotted horizontal line across the graph represents the 68°F “harm threshold” for adult and juvenile fish. Salmon and steelhead begin to suffer harmful effects when water temperatures exceed 68° Fahrenheit. The longer temperatures remain above 68°F and the higher the temperatures rise above 68°F, the more severe the effects.

Water temperatures remain high - and harmful - to salmon and steelhead in the lower Snake and lower Columbia River reservoirs: On the lower Snake River, the Ice Harbor, Little Goose and Lower Monumental reservoirs remain well above the threshold (68 degrees) this week. The Ice Harbor Dam reservoir has consistently maintained mean temperatures above 71°F, and with a high mean temperature of 71.96°F on July 22 and July 23. The Lower Monumental Dam had high mean temperatures of 70.52°F on July 22 and July 23.

On the lower Columbia River reservoirs, current temperatures remain above the 10-year averages for this time of the year, and all reservoirs register temperatures above 69°F. On July 25, 2021, The Dalles Dam reservoir had the highest mean temperature of 71.96°F. This week, the John Day Dam reservoir had the second highest mean temperature of 71.42°F.

A note on the lower Snake River Water Temperature Graph: The mean water temperature data from these reports comes from the USGS Current Conditions for Washington State and the 10-year average water temperature data comes from the Fish Passage Center. USGS began recording water temperatures at Ice Harbor and Lower Monumental on June 16, 2021, Little Goose on June 19, 2021, and Lower Granite on June 18, 2021. Although we are not able to compare spring water temperatures to summer water temperatures, we can see June temperatures rising above the 10-year average and all water temperatures in the lower Snake River are above 60°F.

III. WEEKLY HIGH TEMPERATURES: 7/21-7/27

On the lower Snake River this week, the reservoir behind Ice Harbor Dam registered the highest temperature at 72.50°F - significantly warmer than what coldwater fish require. Lower Monumental Dam reservoir had the second highest temperature at 71.24°F.

On the lower Columbia River, all reservoirs registered high temperatures above 70°F for multiple days. The Dalles Dam had the highest temperature this week at 72.32°F, followed closely by the Bonneville Dam with a high temperature of 72.14°F.

Temperature data included in these reports come from the USGS Current Conditions for Washington State and the Fish Passage Center. Graphs and tables were assembled by SOS Staff.

IV. BREAKING NEWS: HOT WATER IS DEVASTATING SOCKEYE SALMON RETURNING TO THE COLUMBIA AND SNAKE RIVERS THIS SUMMER

Heat-stressed sockeye salmon returning to the Columbia and Snake rivers are dying this summer. Columbia Riverkeeper released heartbreaking video footage and images that show sockeye with large, open lesions and fungus. Sockeye are especially sensitive to water temperatures above 68 degrees; hot waters make them highly susceptible to fungus growth on their skin and to open wounds.¹

Columbia Riverkeeper captured this video on July 16 in the Little White Salmon River - a tributary to the lower Columbia River. Waters in the lower Columbia River currently exceed 71 degrees Fahrenheit - hotter than the legal (and biological) limit of 68°F, which scientists have identified as critical for protecting salmon.² 

You can listen to Umatilla Tribal member Don Sampson talk about what this means for salmon in this video.

Sockeye salmon spawn in mountain lakes above the Snake and upper Columbia rivers.² However, due to the current high water temperatures, sockeye are taking refuge in small, cooler tributaries like the Little White Salmon, delaying their natural upstream migration.³ The Little White Salmon River does not support sockeye spawning, and scientists believe it is highly likely that they will die from disease and heat stress before they are able to reproduce.²

Columbia Basin fish are increasingly in crisis today - thirteen distinct populations are at risk of extinction today. Snake River sockeye are on the federal Endangered Species list and among the most imperiled.
The elevated water temperatures caused by the federal reservoirs and made worse by a changing climate must be addressed, or we will lose these fish.

The four lower Snake River dams kill significant numbers of juvenile (smolts) and adult fish, as the dam’s reservoirs create large, stagnant pools that absorb heat from the sun, reaching lethal temperatures for salmon. These bodies of water inundate and destroy diverse micro-habitats that healthy rivers support, including cold-water refuges that salmon and steelhead rely upon during their migration in the summer months. When available, pockets of cold water can enable adult (moving upstream) and juvenile fish (moving downstream) to rest and recover before continuing their migration. Unfortunately, rising temperatures and reductions in snowpack in recent decades due to climate change are contributing to lower survival and reproductive success for already endangered salmon and steelhead.

The lower Snake and Columbia River dams have disrupted the salmon’s life cycle in various ways, including driving water temperatures past 68°F in the summer for weeks at a time. Hot water temperature affects salmon behavior, reproduction, and survival (adult salmon have difficulty migrating upstream when water temperatures exceed 68°F).⁴ Migration stops altogether when water temperatures reach 72 to 73°F.⁴ Salmon that have stopped or slowed their migration, and languish for days or weeks in warm water, often die from the associated stress and disease (see Issue 1 for more information). On the lower Snake River last week, the reservoir behind Ice Harbor Dam registered the highest temperature at 73.22°F. This week, the Ice Harbor Dam is still well above 68 degrees - with a high temperature of 72.50°F. Similarly, on the lower Columbia River, the Dalles Dam had a high temperature last week and this week at 72.32°F. Salmon are a keystone species, and their loss sends a ripple effect to other species and the ecosystem as a whole. Restoring the lower Snake River is our nation’s very best salmon and river restoration opportunity, and it is our only feasible option for addressing dangerously high water temperatures. River restoration will also help address other problems created for fish by the dams. It will, for example, significantly reduce predator populations and, by increasing current velocity, significantly decrease juvenile salmon migration times to the estuary. All things considered, bypassing the lower Snake River dams is an essential ingredient to protect salmon and steelhead from extinction and to rebuild their populations and the many benefits they provide for the people and ecosystems of the Pacific Northwest and nationwide.

References:
1. The Guardian: Salmon nearly roasted alive in Pacific noth-west heatwave captured on video (July 27, 2021)
2. Columbia Riverkeeper: Salmon Dying from Hot Water in Columbia River (July 27, 2021)
3. NOAA Fisheries: 2015 Adult Sockeye Salmon Passage Report, p. 25 (2016)
4. Columbia Riverkeeper: Hot Water: Dammed rivers and climate change create lethal conditions for key species (July 27, 2021)

V. COLUMBIA RIVERKEEPER: SOME FREQUENTLY ASKED QUESTIONS.

Why are the fish dying at the mouth of the Little White Salmon River?
These fish are adult sockeye salmon that just returned from the ocean. Right now, they should be migrating much further up the Columbia River to spawn in mountain lakes in the Okanogan, Yakima, and Snake river systems. Snake River sockeye are on the federal Endangered Species list and dangerously close to extinction.

Map of the Columbia River Basin. Purple oval shows the mouth of the Little White Salmon River. Red stars show major sockeye spawning areas. Black dashes show large hydroelectric dams. >>

Why are sockeye there? Is it natural?
Because the Columbia River is too hot, these sockeye are taking refuge in small, cold tributaries like the Little White Salmon River instead of completing their natural upstream migration.¹ The Little White Salmon River does not support sockeye spawning, and sockeye are only seen here when Columbia gets too hot.

Why is the Columbia River too hot?
Dams on the Columbia and Lower Snake Rivers create large, stagnant reservoirs that soak up the sun’s energy, making the water too hot for salmon.² Climate change is making this bad situation even worse.³

Will these sockeye eventually go upstream to spawn?
No. They will very likely die in the Little White Salmon River of disease and heat stress, without spawning.⁴

Is this a one-time, freak occurrence?
No. In 2015, when roughly 250,000 sockeye died in the Columbia and Snake rivers because of hot water, sockeye also sought refuge and died in the Little White Salmon River and nearby tributaries.⁵ Scientists predict that fish kills like this will become more common as dams and climate change continue to warm the rivers and likely cause the extinction of Snake River sockeye⁶—unless we address how the dams warm the Columbia and Snake rivers.

Why do these fish look like they have mold on them?
The fuzzy-looking white patches on these sockeye are likely a fungal infection that attacks salmon stressed by hot water.⁷

How many sockeye will die of warm water this year?
It’s too soon to tell. Here’s what we know: Right now, tens of thousands of sockeye remain in the dangerously warm Columbia and Lower Snake rivers. As the rivers get even hotter in August and September, many of these fish may perish.

FAQ References:
1. See NOAA Fisheries, 2015 Adult Sockeye Salmon Passage Report, p. 25 (2016).
2. U.S. EPA, Temperature Total Maximum Daily Load for the Columbia and Lower Snake Rivers, pp. 47–50 (May 18, 2020) (Columns E and F in Tables 6-6 through 6-9 show the heat pollution caused by dams individually and cumulatively during the summer and fall.).
3. Id. at 70 (explaining that climate change has already caused water temperature increases of 1 to 2 °C in the Columbia and Snake rivers).
4. See U.S. EPA, Columbia River Cold Water Refuges Plan, p. 34 (2021) (explaining that sockeye do not successfully use cold water refuges).
5. See Note 1, supra.
6. Crozier et al., Snake River sockeye and Chinook salmon in a changing climate: Implications for upstream migration survival during recent extreme and future climates, 15 PLoS ONE 9, p.2 (2020) (modeling survival probability of Snake River sockeye assuming water temperatures resulting from dams and future climate conditions).
7. See Note 1, supra.

LINKS TO RECENT NEWS:

• The Guardian: Salmon nearly roasted alive in Pacific noth-west heatwave captured on video (July 27, 2021)
• Earthjustice: How the Courts Are Keeping Salmon Alive (July 23, 2021)
• Trout Unlimited: Guaranteed: they will come back (July 22, 2021)
• Atmos Magazine: The Frontline - To Our Relatives in the Water (July 19, 2021)

 Martha Campos is the Hot Water Report Coordinator with Save Our wild Salmon this summer while she resides on Kizh/Tongva ancestral lands in California. Martha holds a BA from the University of California, Davis in Native American Studies (and two minors: Environmental Policy, Analysis, and Planning and Climate Science and Policy) and is a queer, non-binary person of color with ancestral roots in Mexico.

I. INTRODUCTION

Welcome to Save Our wild Salmon’s Hot Water Report 2021. During the summer, this weekly report will provide an update on real-time water temperatures in the lower Snake and Columbia river reservoirs via graphs and analyses, a report on the highest weekly water temperature at the forebay/reservoir of each dam, and the status of adult returns for the different salmon and steelhead populations as they make their way back to their natal spawning grounds. We’ll share information from scientists, fishers, guides, advocates, and other experts about the challenges facing the Columbia and Snake rivers - and opportunities we have to restore healthy rivers and to recover abundant fish populations and the many benefits they deliver to the Northwest’s culture, economy, and ecology.

The once-abundant anadromous native fish populations that call the Columbia-Snake River Basin home are struggling to survive primarily due to multiple harmful effects caused by the system of federal dams and their reservoirs. The federal hydro-system creates conditions that harm and kill both juvenile and adult fish, including by elevating water temperatures in the large, stagnant reservoirs, especially in the summer months. As cold water species, these salmon and steelhead begin to suffer harmful effects when water temperatures exceed 68° Fahrenheit. The longer and higher temperatures rise above 68°F, the greater the harm, including disruption in their migration, increased metabolism, increased susceptibility to disease, reduced fecundity or reproductive potential (by reducing egg viability), and in the worst case - death.

These harmful hot water episodes above 68 degrees in the Columbia and Snake Rivers are increasing in duration, frequency, and intensity. Our changing climate is making a very bad situation for the Northwest’s iconic fish worse. Our region and nation must take urgent action to lower these high temperatures - or scientists tell us that we will lose these species forever. Restoring a freely flowing lower Snake River by removing its four federal dams is our best and very likely only option for lowering water temperatures in this 140-mile stretch of river in southeast Washington State. Restoring the Snake River is one essential part of what must be a larger regional strategy to protect and rebuild healthy, abundant salmon and steelhead populations in order to benefit other fish and wildlife populations, including critically endangered Southern Resident orcas, to honor tribal rights, and to ensure prosperous communities across the Northwest.

Will you be on the river this summer? Do you have a story or photo you would like to share? Please send them to Martha Campos

The Hot Water Report is a joint project of the Save Our wild Salmon Coalition, Washington Sierra Club, Columbia Riverkeeper, Idaho Rivers United, National Wildlife Federation, Snake River Waterkeeper, Northwest Steelheaders, Defenders of Wildlife, and Endangered Species Coalition.

II. READING THE DATA - Lower Snake and Columbia River Temperatures

The daily mean temperature at the four reservoir forebays (immediately upstream from the dam) in the lower Snake River (above) and the lower Columbia River (below) for 2021 is represented with solid lines and their 10-year average (2011-2021) temperatures with dashed lines of the same color. The dotted line across the graph represents the 68°F “harm threshold” for adult and juvenile fish. Salmon and steelhead begin to suffer harmful effects when water temperatures exceed 68° Fahrenheit. The longer temperatures remain above 68°F and the higher the temperatures rise above 68°F, the more severe the potential effects, including: increased metabolism, increased susceptibility to disease, reduced fecundity or reproductive potential, and/or death.

A note on the lower Snake River Water Temperature Graph: The mean water temperature data from these reports comes from the USGS Current Conditions for Washington State and the 10-year average water temperature data comes from the Fish Passage Center. USGS began recording water temperatures at Ice Harbor and Lower Monumental on June 16, 2021, Little Goose on June 19, 2021, and Lower Granite on June 18, 2021. Although we are not able to compare spring water temperatures to summer water temperatures, we can see June temperatures rising above the 10-year average and all water temperatures in the lower Snake River are above 60°F.

Harmful water temperatures continue to rise in the lower Snake River reservoirs: This week, all reservoirs exceed the 10-year average for this time of the year. On the lower Snake River, the Ice Harbor, Lower Monumental, and Little Goose reservoirs have all peaked over the threshold (68 degrees) this week. On July 1st, the Ice Harbor’s reservoir significantly peaked above the 68°F threshold and continued to peak throughout this week, with a high mean temperature of 71.24°F.

This week, Lower Granite Dam's reservoir had mean temperatures just below the 68 degree threshold. Temperatures in this reservoir in the summer months are typically slightly cooler than the three downstream reservoirs on the lower Snake because the U.S. Army Corps of Engineers releases cold water from behind Dworshak Dam into the Clearwater River (tributary to the lower Snake River) in early July. However this year, on June 22nd, due to the extreme heat wave in the Pacific Northwest, the Army Corps began to release 43-degree Fahrenheit (6-degree Celsius) water from Dworshak Dam to prevent the water temperature from reaching 68 degrees Fahrenheit in the Lower Granite Dam’s reservoir near Lewiston (ID) and Clarkston (WA). Despite the release of cold water from the Dworshak reservoir since late June, all reservoirs immediately downstream from the Lower Granite Dam continue to experience temperatures above 68°F. As long as these four dams remain in place, the benefits of Dworshak’s cold flows are limited and serve only as a short-term solution to cooling water temperatures to the Lower Granite Dam’s reservoir. EPA models show that a freely flowing lower Snake would carry these cooler waters all the way downstream to its confluence with the Columbia River near the Tri-Cities (WA) (see Issue 2 for more information).

Like the lower Snake River, current reservoir temperatures in the lower Columbia River are above the 10-year average for this time of the year. Additionally, all four reservoirs registered temperatures above 68°F. The longer temperatures remain above 68°F and the higher they rise above this key threshold, the more severe the stresses and harms. (see Issue 1 for more information).

III. WEEKLY HIGH TEMPERATURES: 6/30-7/6

On the lower Snake River this week, the Ice Harbor Dam registered the highest temperature at 71.60°F - significantly above the level that coldwater fish require. The Little Goose Dam had the second highest temperature at 71.24°F.

On the lower Columbia River, all reservoirs registered high temperatures above 68°F for multiple days. The reservoirs behind the Dalles and Bonneville Dams registered the highest temperature this week at 70.52°F, followed closely by the John Day Dam with a high temperature of 70.34°F.

Temperature data included in these reports come from the USGS Current Conditions for Washington State and the Fish Passage Center. Graphs and tables were assembled by SOS Staff.

IV. A Review of 2015 Hot Water and Fish Kills in the Lower Snake and the lower Columbia Rivers

*Note on 2015 Lower Snake and Columbia River Temperatures Graphs: The daily mean temperature at the four reservoir forebays in the lower Snake River and the lower Columbia River for 2015 is represented with solid lines. The mean water temperature data from these reports comes from the USGS Current Conditions for Washington State.

Beginning in late June of 2015, the Columbia-Snake Basin began to experience what ultimately became 70 days of sustained hot water that killed an estimated 250,000 adult sockeye salmon as they returned from the Pacific Ocean en route to their natal rivers and streams in the Columbia-Snake Basin. It was an unprecedented and devastating fish die-off. Early in the migration season, sockeye experienced record hot water temperatures above 68°F on June 24th at Bonneville Dam on the Columbia River and on June 22nd at Ice Harbor Dam on the lower Snake River. In July, reservoirs in the lower Columbia and lower Snake River reached temperatures of 72-73°F for a period of several weeks. Notably, the Ice Harbor reservoir on the lower Snake reached a high water temperature of 73.40°F on July 12th, 2015. Also, the Bonneville reservoir reached 73.40°F on July 9th and July 10th, and July 19th-July 21st. The hot river waters continued through August into early September, when temperatures finally dropped below 68°F.

Due to the combined effects of extremely hot air and water temperatures, low 2014-15 snowpack that led to low 2015 runoff, and the presence of dams and their reservoirs, at least 96% of endangered returning adult Snake River sockeye salmon died - a species with an already low population level - during their upriver migration through the lower Columbia and Snake Rivers. Before 2015, the Snake River sockeye and other Snake River salmon (sockeye, spring/summer Chinook, fall Chinook, and steelhead) already experienced reduced migrations and high mortality due to high water temperatures above 68°F (20°C).² Each year, steelhead, fall Chinook, and sockeye have greater exposure to high temperatures than adult spring/summer Chinook because they migrate later in the summer when temperatures are highest.² Snake River sockeye and other Snake River salmon faced deadly conditions in 2015, and climate change exacerbates these extreme conditions - lower water flows and hotter water temperatures - causing the reservoir to become dangerous environments for endangered and threatened salmon species each year.^2,3

2021's water temperatures in the Snake and Columbia rivers are shaping up to be as bad or worse as 2015. A recent Idaho Statesman article, “This is worse’ than 2015: Northwest weather heats rivers, puts Idaho sockeye in danger” highlights that “salmon in the Columbia, Snake and even Salmon rivers are swimming into lethally hot waters that are at even higher temperatures than when nearly all of the Columbia and Snake sockeye died in 2015.” In late June this year, water temperatures in the reservoir behind the Little Goose dam on the lower Snake River of a high maximum temperature of 73.04°F and a high mean temperature of 71.60°F on June 28th. This week, Ice Harbor is the last reservoir to have reached above 68°F, with a high maximum temperature of 71.60°F on July 6th, which strongly indicates that salmon are experiencing hot water temperatures earlier than in 2015. Unfortunately, so far this summer, water conditions are continuing above 68°F (20°C), and without comprehensive solutions, endangered salmon will continue to suffer high death rates.²

Through the years, scientists have raised the alarm about the pressing threat that hot waters represent to salmon and steelhead. Most recently in February this year, 68 salmon and fisheries scientists wrote a letter to Northwest policymakers with actions necessary to protect and restore abundant salmon and steelhead runs to the Columbia-Snake River Basin.

In the letter, fish scientists noted the cumulative impacts of the 8 dams Snake River salmon must navigate migrating as both smolts headed downstream and adults returning to their home rivers have thwarted salmon and steelhead recovery. The lower Snake River dams create a lethal corridor blocking salmon from high quality spawning habitat found in the Snake River basin, and opening access to thousands of miles of pristine habitat provides the highest likelihood of restoring salmon to healthy numbers. Furthermore, to prevent salmon species from migrating through dangerous water temperatures and to prevent fish deaths like in 2015, we need Congressional leadership in 2021 to make long overdue investments to: (1) restore salmon and protect orcas; (2) honor commitments to Northwest tribes; (3) strengthen our energy and transportation infrastructure, and (4) sustain more just and prosperous communities across the region. Restoring the lower Snake River is our very best opportunity to restore endangered salmon and steelhead to abundance in the Northwest.⁴

References:
1. Lessons from the 2015 Columbia-Snake Salmon Kill From the desk of Pat Ford (2016).
2. Letter from fifty-five scientists to Northwest policymakers: Science-based solutions are needed to address increasingly lethal water temperatures in the lower Snake River (2019).
3. Earthjustice, WHY IS IT DIFFERENT THIS TIME? Why the removal of the four Snake River dams is a feasible and necessary action to save wild salmon.
4. Letter from 68 scientists to Northwest policymakers: Scientists’ letter on the need for lower Snake River dam removal to protect salmon and steelhead from extinction and restore abundant, fishable population(2021).

LINKS TO RECENT NEWS:

• Lewiston Tribune: Idaho wildlife managers to trap and truck sockeye to spare them exposure to too-warm waters (July 2, 2021)
• Idaho Statesman: ‘This is worse’ than 2015: Northwest weather heats rivers, puts Idaho sockeye in danger (July 1, 2021)
• The Seattle Times: Washington state board to uphold temperature limits in Columbia, Snake rivers (June 29, 2021)

 Martha Campos is the Hot Water Report Coordinator with Save Our wild Salmon this summer while she resides on Kizh/Tongva ancestral lands in California. Martha holds a BA from the University of California, Davis in Native American Studies (and two minors: Environmental Policy, Analysis, and Planning and Climate Science and Policy) and is a queer, non-binary person of color with ancestral roots in Mexico.

I. INTRODUCTION

Welcome to Save Our wild Salmon’s Hot Water Report 2021. During the summer, this weekly report will provide an update on real-time water temperatures in the lower Snake and Columbia river reservoirs via graphs and analyses, a report on high weekly water temperature at the forebay/reservoir of each dam, and the status of adult returns for the different salmon and steelhead populations as they make their way back to their natal spawning grounds. We’ll also hear first-hand from scientists, anglers, guides, advocates, and other experts about challenges facing the Columbia and Snake rivers - and the opportunities we have to restore the healthier river conditions needed to support abundant fish populations and the many benefits they bring to the Northwest’s culture, economy and ecology.

The once-abundant anadromous native fish populations that call the Columbia-Snake River Basin home are struggling to survive today primarily due to harmful effects caused by the system of federal dams and their reservoirs. The federal hydro-system creates conditions that harm and kill both juvenile and adult salmon and steelhead, including by elevating water temperatures in the large, stagnant reservoirs, especially in the summer months. As cold water species, these fish begin to suffer harmful effects when water temperatures exceed 68° Fahrenheit. The longer and higher temperatures rise above 68°F, the greater the harm, including disruption in their migration, increased metabolism, increased susceptibility to disease, reduced fecundity or reproductive potential (by reducing egg viability), and in the worst case - death.

These hot waterepisodes above 68 degrees in the Columbia and Snake Rivers are increasing in duration, frequency, and intensity. Our changing climate is making a bad situation for the Northwest’s iconic fish worse. Our region and nation must take urgent action to lower these high temperatures or we will lose these species forever. Restoring a freely flowing lower Snake River by removing its four federal dams is our best and likely only option for lowering water temperatures in this 140-mile stretch of river in southeast Washington State. Restoring the Snake River is one essential part of what must be a larger regional strategy to protect and rebuild healthy, abundant salmon and steelhead populations in order to benefit other fish and wildlife populations, including critically endangered Southern Resident orcas, to honor tribal rights, and to ensure prosperous communities across the Northwest.

Will you be on the river this summer? Do you have a story or photo you would like to share? Please send them to Martha Campos

The Hot Water Report is a joint project of the Save Our wild Salmon Coalition, Washington Sierra Club, Columbia Riverkeeper, Idaho Rivers United, National Wildlife Federation, Snake River Waterkeeper, Northwest Steelheaders, and Defenders of Wildlife.

II. READING THE DATA - Lower Snake and Columbia River Temperatures

The daily mean temperature at the four reservoir forebays (immediately upstream from the dam) in the lower Snake River (above) and the lower Columbia River (below) for 2021 is represented with solid lines and their 10-year average (2011-2021) temperatures with dashed lines of the same color. The dotted line across the graph represents the 68°F “harm threshold” for adult and juvenile fish. Salmon and steelhead begin to suffer harmful effects when water temperatures exceed 68° Fahrenheit. The longer temperatures remain above 68°F and the higher the temperatures rise above 68°F, the more severe the potential effects, including: increased metabolism, increased susceptibility to disease, reduced fecundity or reproductive potential, and/or death.

A note on the lower Snake River Water Temperature Graph: The mean water temperature data from these reports comes from the USGS Current Conditions for Washington State and the 10-year average water temperature data comes from the Fish Passage Center. USGS began recording water temperatures at Ice Harbor and Lower Monumental on June 16, 2021, Little Goose on June 19, 2021, and Lower Granite on June 18, 2021. Although we are not able to compare spring water temperatures to summer water temperatures, we can see the temperatures rising above the 10-year average and all water temperatures in the lower Snake River are above 60°F.

Temperatures in the lower Snake River and the lower Columbia River reservoirs over the last seven days are all trending at or above the 10-year average for this time of year. As we officially enter the summer season, temperatures in the mainstem lower Columbia river, like the Snake, are steadily rising toward the 68 degree “harm threshold” for salmon and steelhead.

III. WEEKLY HIGH TEMPERATURES: 6/14-6/22

On the lower Snake River this week, Lower Granite Dam’s reservoir registered the highest temperature at 65.66°F, followed closely by Little Goose Dam with 65.48°F.

The McNary Dam registered the highest temperature on the lower Columbia River this week at 65.48°F. The Dalles and the Bonneville Dam also registered a high temperature at 65.3°F.

Temperature data included in these reports come from the USGS Current Conditions for Washington State and the Fish Passage Center. Graphs and tables were assembled by SOS Staff.

IV. How the Snake and Columbia River reservoirs impact cold-water species of salmon and steelhead.

Historically, abundant Snake and Columbia River salmon and steelhead delivered vast cultural, economic, nutritional, and ecological benefits to the people and fish and wildlife of the Pacific Northwest. Not long ago, the Columbia Basin would experience millions of adult salmon and steelhead that flooded into the Columbia River Basin each year. Chinook, or King salmon, are the largest and richest of the salmonid species. They are also notably the primary food source (roughly 80 percent of their overall diet) of the critically endangered Southern Resident orcas. Columbia Basin chinook can spend five or more years in the Pacific Ocean before they return to freshwater to spawn.

These fish, however, are in crisis - thirteen distinct populations in the Columbia Basin are at risk of extinction today. The elevated water temperatures caused by the reservoirs and made worse by a changing climate must be addressed or scientists tell us we will lose these fish forever. Reservoirs created by these dams warm water above the temperatures of freely flowing rivers by slowing the current and creating large pools that absorb large amounts of solar radiation. These bodies of water inundate and destroy diverse micro-habitats that healthy rivers support, including cold-water refuges that salmon and steelhead rely upon during their migration in summer months. When available, these vital pockets of cold water can enable adult (moving upstream) and juvenile fish (moving downstream) to rest and recover before continuing their migration. Rising temperatures and reductions in snowpack in recent decades due to climate change has resulted in lower survival and reproductive success for endangered salmon and steelhead.

How temperature affects salmon behavior, reproduction, and survival: According to the National Wildlife Federation, the optimum water temperature range for most salmon is approximately 55 to 64 degrees Fahrenheit. While different stocks and species of salmon and steelhead may have different requirements and temperature tolerances, the National Ocean and Atmospheric Administration indicates that Chinook salmon, for example, prefer/require certain water temperatures for all phases of their life history: spawning, egg survival, smoltification, and migration:

Influence of water temperatures on Chinook salmon spawning and egg incubation:

• Upstream migration will cease if temperatures are below 3.3°C (37.94°F) or above 20°C (68°F).
• The majority of spawning occurs between 6°C (42.8°F) and 15 °C (59°F)
• The optimal temperature range for egg survival is 8°C (46.4°F) to 12°C (53.6°F).
• The optimal temperature range for development to the alevin (larval stage after hatching before yolk absorption stage) is 4°C (39.2°F) to 8°C (46.4°F)

Influence of water temperatures on smoltification by Chinook salmon:

• Water temperature above 14°C (57.2°F) and below 7°C (44.6°F) can cause mortality in fry.
• High (sub-lethal) water temperatures accelerates growth of fry, but can also result in increased susceptibility to disease.
• High temperatures can lead to early seaward emigration by influencing physiology.

The lower Snake and Columbia river dams have disrupted the salmon’s life cycle in various ways, including by driving water temperatures past 68°F in the summer for weeks at a time. This week, the dams in the lower Columbia River and the Little Goose and Lower Granite dams in the lower Snake River are reaching the above optimum water temperature range of 55 to 64 degrees Fahrenheit.

Restoring the lower Snake River is our only feasible option for addressing its dangerously high water temperatures. River restoration will also help address other problems created for fish by the dams. It will, for example, significantly reduce predator populations and by increasing current velocity, significantly decrease juvenile salmon migration times to the estuary. All things considered, bypassing the lower Snake River dams is an essential ingredient for protecting salmon and steelhead from extinction and for rebuilding their populations and the many benefits they provide for the people and ecosystems of the Pacific Northwest and nation.

V. ABOUT THE SAVE OUR WILD SALMON COALITION

Founded in 1991, Save Our wild Salmon (SOS) is a diverse coalition of organizations working together to secure policies to protect and restore healthy, self-sustaining and fishable populations of salmon and steelhead in the marine- and fresh-waters of the Pacific Northwest. As many as 16 million salmon and steelhead once returned to the Columbia-Snake River Basin annually. Today in the Snake River Basin, all four remaining populations face extinction. The steep losses of this keystone species in the Columbia Basin and across the Northwest has had devastating effects on many communities, cultures, economies and other fish and wildlife populations.

LINKS TO FURTHER INFORMATION:

• Association of Northwest Steelheaders: This Summer Could Shape the Future of Pacific Northwest Salmon (June 14, 2021)
• National Oceanic and Atmospheric Administration: The Influence of In-stream Habitat Characteristics onChinook Salmon (Oncorhynchus tshawytscha) (November 2002)
• National Park Service: The Salmon Life Cycle (July 2019)
• The National Wildlife Federation: Chinook Salmon

Martha Campos is the Hot Water Report Coordinator with Save Our wild Salmon this summer while she resides on Kizh/Tongva ancestral lands in California. Martha holds a BA from the University of California, Davis in Native American Studies (and two minors: Environmental Policy, Analysis, and Planning and Climate Science and Policy) and is a queer, non-binary person of color with ancestral roots in Mexico.

I. INTRODUCTION

Welcome to Save Our wild Salmon’s Hot Water Report 2021. During the summer, this weekly report will provide an update on real-time water temperatures in the lower Snake and Columbia river reservoirs via graphs and analyses, a report on the highest weekly water temperature at the forebay/reservoir of each dam, and the status of adult returns for the different salmon and steelhead populations as they make their way back to their natal spawning grounds. We’ll also hear first-hand from scientists, fishers, guides, advocates, and other experts about challenges facing the Columbia and Snake rivers - and the opportunities we have to restore these rivers, leading to the recovery of healthy, resilient fish populations and the many benefits they deliver to the Northwest’s culture, economy, and ecology.

The once-abundant anadromous native fish populations that call the Columbia-Snake River Basin home are struggling to survive primarily due to multiple harmful effects caused by the system of federal dams and their reservoirs. The federal hydro-system creates conditions that harm and kill both juvenile and adult salmon and steelhead, including by elevating water temperatures in the large, stagnant reservoirs, especially in the summer months. As cold water species, these fish begin to suffer harmful effects when water temperatures exceed 68° Fahrenheit. The longer and higher temperatures rise above 68°F, the greater the harm, including disruption in their migration, increased metabolism, increased susceptibility to disease, reduced fecundity or reproductive potential (by reducing egg viability), and in the worst case - death.

These harmful hot water episodes above 68 degrees in the Columbia and Snake Rivers are increasing in duration, frequency, and intensity. Our changing climate is making this bad situation for the Northwest’s iconic fish even worse. Our region and nation must take urgent action to lower these temperatures - or scientists tell us that we will lose these species forever. Restoring a freely flowing lower Snake River by removing its four federal dams is our best and very likely only option for lowering water temperatures in this 140 mile stretch of river in southeast Washington State. Restoring the Snake River is one essential part of what must be a larger regional strategy to protect and rebuild healthy, abundant salmon and steelhead populations in order to benefit other fish and wildlife populations, including critically endangered Southern Resident orcas, to honor tribal rights, and to ensure prosperous communities across the Northwest.

Will you be on the river this summer? Do you have a story or photo you would like to share? Please send them to Martha Campos

The Hot Water Report is a joint project of the Save Our wild Salmon Coalition, Washington Sierra Club, Columbia Riverkeeper, Idaho Rivers United, National Wildlife Federation, Snake River Waterkeeper, Northwest Steelheaders, Defenders of Wildlife, and Endangered Species Coalition.

II. READING THE DATA - Lower Snake and Columbia River Temperatures

The daily mean temperature at the four reservoir forebays (immediately upstream from the dam) in the lower Snake River (above) and the lower Columbia River (below) for 2021 is represented with solid lines and their 10-year average (2011-2021) temperatures with dashed lines of the same color. The dotted line across the graph represents the 68°F “harm threshold” for adult and juvenile fish. Salmon and steelhead begin to suffer harmful effects when water temperatures exceed 68° Fahrenheit. The longer temperatures remain above 68°F and the higher the temperatures rise above 68°F, the more severe the potential effects, including: increased metabolism, increased susceptibility to disease, reduced fecundity or reproductive potential, and/or death. (see Issue 1 for more detailed information).

A note on the lower Snake River Water Temperature Graph: The mean water temperature data from these reports comes from the USGS Current Conditions for Washington State and the 10-year average water temperature data comes from the Fish Passage Center. USGS began recording water temperatures at Ice Harbor and Lower Monumental on June 16, 2021, Little Goose on June 19, 2021, and Lower Granite on June 18, 2021. Although we are not able to compare spring water temperatures to summer water temperatures, we can see June temperatures rising above the 10-year average and all water temperatures in the lower Snake River are above 60°F. Harmful water temperatures reached in the lower Snake and lower Columbia River reservoirs: This week, all reservoirs exceed the 10-year average for this time of the year. On the lower Snake River, the Lower Monumental and Little Goose Dams have peaked over the threshold (68 degrees) this week. In addition, the Little Goose dam has significantly peaked above the 68°F threshold, with a high mean temperature of 71.6°F.

Like the lower Snake River, current reservoir temperatures in the lower Columbia River are above the 10-year average for this time of the year. The Dalles, Bonneville, John Day and McNary reservoirs all registered temperatures at or above 68°F.

III. WEEKLY HIGH TEMPERATURES: 6/23-6/29

On the lower Snake River this week, the Little Goose Dam registered the highest temperature at 73.04°F - nearly 5°F warmer than levels that coldwater fish require. Lower Monumental Dam had the second-highest temperature at 69.8°F.

On the lower Columbia River, all reservoirs registered high temperatures above 68°F for multiple days. Both John Day Dam and the Bonneville Dam registered the highest temperature this week at 69.8°F, followed closely by the McNary Dam with a high temperature of 69.44°F.

Temperature data included in these reports come from the USGS Current Conditions for Washington State and the Fish Passage Center. Graphs and tables were assembled by SOS Staff.

 IV. COLUMBIA RIVERKEEPER REPORT (2017): Removing dams will reduce lower Snake River water temperatures and deliver critical survival benefits to endangered salmon and steelhead

In 2015, high water temperatures driven by hot weather and a low snowpack killed more than 250,000 salmon in the Columbia and Snake rivers. This incident of mass mortality inspired SOS member organization Columbia Riverkeeperto publish a report - Columbia Riverkeeper White Paper: Computer modeling shows that Lower Snake River dams caused dangerously hot water for salmon in 2015 - that evaluated what the water temperatures of the lower Snake would have been during the summer of 2015 if its four federal dams did not exist.

Using an U.S. Environmental Protection Agency (EPA) water temperature model, Columbia Riverkeeper found that each of the four reservoirs behind the dams increased the river temperature by about 2 °F. The reservoirs create large, stagnant pools that steadily absorb heat from the sun. When warm water from one reservoir moves downstream to the next pool, the already warmed water is stopped again by the next dam and continues to heat up. The model indicates clearly that this effect would be absent from the free-flowing lower Snake River.

Since Columbia Riverkeeper published its study in 2017, federal science agencies have released more information corroborating its findings. First, the U.S. Army Corps of Engineers used EPA’s model, as well as another water temperature model, to recreate Columbia Riverkeeper’s study—and got similar results. Second, the EPA released a study showing that, in warm years, water flowing into the lower Snake River is cool enough for fish, but water flowing out of the lower Snake River is too hot and the dams cause much of this heat pollution.

A reservoir-free lower Snake River flows freely and does not absorb the same amount of solar radiation. Considerably cooler waters deliver big benefits to migrating juvenile and adult salmon and steelhead populations – leading to increased survival and reproductive success. A free-flowing lower Snake River also has the additional benefit of cold waters that are released from behind the Dworshak reservoir upstream on the Clearwater River in the hot summer months.

Dworshak dam’s large reservoir is used to deliver cold water into the Clearwater River, which enters the Snake River at Lewiston, Idaho. The Army Corps has traditionally released the cold water from the Dworshak Dam after July 4th. However this year, on June 22nd, due to the extreme heat wave in the Pacific Northwest, the Army Corps began to release “43-degree Fahrenheit (6-degree Celsius) water at Dworshak Dam” to prevent the water temperature from reaching 68 degrees Fahrenheit and higher at the Lower Granite Dam’s reservoir near Lewiston (ID) and Clarkston (WA).

With the dams in place, the cooling benefits of Dworshak releases are limited to the uppermost reservoir of Lower Granite dam. This year, for example, the Lower Granite reservoir reached 68.36°F (20.2°C) on Friday June 25, 2021 (see table above). The release of cold water from the Dworshak reservoir cooled the Lower Granite reservoir to below the 68°F threshold for three days. Immediately downstream, however, the Little Goose reservoir experienced the highest water temperatures so far this summer - at 73.04°F (22.8°C). Despite the release of cold water from the Dworshak reservoir, the Little Goose Dam and Lower Monumental Dam (immediately downstream from Lower Granite Dam) continued to experience temperatures well above 68°F. As long as these four dams remain in place, the benefits of Dworshak’s cold flows are limited and serve only as a short-term solution to cooling water temperatures to the Lower Granite Dam’s reservoir.

In recent years, the lower Snake River routinely suffers weeks and/or months of hot water with temperatures above – and often well above - 68°F (the upper end of the comfort zone for coldwater fish like salmon and steelhead) - and this year is no exception. However, by restoring this 140-mile stretch of river through dam removal, EPA models used in the Columbia Riverkeeper report show that while temperatures in a freely flowing river may spike above 68 degrees periodically, they will quickly return to the cool temperatures that salmon and steelhead need to survive and thrive. Cold summer flows from Dworshak further help keep temperatures healthy for fish all the way downstream to where the Snake River joins the Columbia River in south-central Washington State near the Tri-Cities.

In summarizing findings of the study, Miles Johnson, senior attorney at Columbia Riverkeeper, notes that, "removing the four lower Snake River dams would keep the river cooler and help salmon reach their spawning areas. This is critical for healthy salmon and a healthy river – especially as the changing climate tightens its grip on our waters in the Northwest. It's time for bold action to protect the Northwest's fishing traditions, orcas, and salmon. It’s time to restore the lower Snake River."

A 2016 court ruling that invalidated the federal government’s latest Columbia-Snake salmon plan as inadequate and illegal highlighted, among other things, the government’s failure to account for the growing impacts of a changing climate on the already endangered wild salmon and steelhead populations of the Snake and Columbia rivers. Unfortunately, the new plan developed during the Trump Administration in response to that court ruling by the federal agencies in charge (Bonneville Power Administration, Army Corps of Engineers, NOAA-Fisheries) still fails to contain any effective strategy to maintain cool, salmon-friendly water temperatures in these reservoirs in summer months. The Trump Plan has been challenged in court by the Nez Perce Tribe, state of Oregon and more than a dozen conservation and fishing organizations (and members of the Save Our wild Salmon Coalition).

References:
1. U.S. Army Corps of Engineers, Final Environmental Impact Statement for Columbia River System Operations, Appendix D, p. A-1-28 (2020).
2. EPA, Columbia and Lower Snake River Temperature TMDL, pp. 47–50 (2020).

LINKS TO FURTHER INFORMATION:

• The Lewiston Tribune: Cold water released from N. Idaho dam to help salmon (June 24, 2021)
• Trout Unlimited: Debunking the ‘it’s the ocean’ excuse to protect Snake River dams (June 24, 2021)
• Oregon Public Broadcasting: Hot salmon: Heat wave brings concern over river-water temperatures (June 27, 2021)
• The Seattle Times: Pacific Northwest heat waves sets up ‘grim’ migration for salmon on Columbia, Snake Rivers (June 29, 2021)

  Martha Campos is the Hot Water Report Coordinator with Save Our wild Salmon this summer while she resides on Kizh/Tongva ancestral lands in California. Martha holds a BA from the University of California, Davis in Native American Studies (and two minors: Environmental Policy, Analysis, and Planning and Climate Science and Policy) and is a queer, non-binary person of color with ancestral roots in Mexico.

I. INTRODUCTION

Welcome to Save Our wild Salmon’s Hot Water Report 2021. During the summer, this weekly report provides updates on real-time water temperatures in the lower Snake and Columbia river reservoirs via graphs and analyses, reports on the highest weekly water temperature at the forebay/reservoir of each dam, and the status of adult returns for different salmon and steelhead populations as they make their way back to their natal spawning grounds. We’ll share information from scientists, fishers, guides, advocates, and other experts about the challenges facing the Columbia and Snake rivers - and opportunities we have to restore healthy rivers and to recover abundant fish populations and the many benefits they deliver to the Northwest’s culture, economy, and ecology.

The once-abundant anadromous native fish populations that call the Columbia-Snake River Basin home are struggling to survive primarily due to multiple harmful effects caused by the system of federal dams and their reservoirs. The federal hydro-system creates conditions that harm and kill both juvenile and adult fish, including by elevating water temperatures in large, stagnant reservoirs, especially in the summer months. As cold water species, salmon and steelhead begin to suffer harmful effects when water temperatures exceed 68° Fahrenheit. The longer and higher temperatures rise above 68°F, the greater the harm, including disruption in their migration, increased metabolism, increased susceptibility to disease, reduced fecundity or reproductive potential, suffocation, and in the worst case - death.

These harmful hot water episodes above 68 degrees in the Columbia and Snake rivers are increasing in duration, frequency, and intensity. Our changing climate is making an already bad situation for the Northwest’s emblematic fish worse. Our region and nation must take urgent action to cool these waters or we will lose these species forever. Restoring a freely flowing lower Snake River by removing its four federal dams is our best and very likely only option for lowering water temperatures in this 140-mile stretch of river in southeast Washington State. Restoring the Snake River is one essential part of what must be a larger regional strategy to protect and rebuild healthy, abundant salmon and steelhead populations in order to benefit other fish and wildlife populations, including critically endangered Southern Resident orcas, to honor tribal rights, and to ensure prosperous communities across the Northwest.

Will you be on the river this summer? Do you have a story or photo you would like to share? Please send them to Martha Campos

The Hot Water Report is a joint project of the Save Our wild Salmon Coalition, Washington Sierra Club, Columbia Riverkeeper, Idaho Rivers United, National Wildlife Federation, Snake River Waterkeeper, Northwest Steelheaders, Defenders of Wildlife, and Endangered Species Coalition.

II. READING THE DATA - Lower Snake and Columbia River Temperatures

The daily mean temperature at the four reservoir forebays (immediately upstream from each dam) in the lower Snake River (above) and the lower Columbia River (below) for 2021 is represented with solid lines and their 10-year average (2011-2021) temperatures with dashed lines of the same color. The dotted horizontal line across the graph represents the 68°F “harm threshold” for adult and juvenile fish. Salmon and steelhead suffer harmful effects when water temperatures exceed 68° Fahrenheit. The longer temperatures remain above 68°F and the higher the temperatures rise above 68°F, the more severe the effects.

Fortunately, water temperatures have begun to drop but at this time they still remain high - and harmful - for salmon and steelhead in the lower Snake and lower Columbia River reservoirs: On the lower Snake River, the waters in the Ice Harbor, the Lower Monumental, and the Little Goose reservoirs continue to exceed the ‘harm threshold’ (68 degrees) this week. On August 25th, the Ice Harbor reservoir had a high mean temperature of 71.24°F and the Lower Monumental reservoir had a high mean temperature of 70.52°F.

On the lower Columbia River, current reservoir temperatures continue to exceed the ‘harm threshold’ (68 degrees). On August 25th, The Dalles and John Day reservoir had the highest mean temperature of 70.52°F. The Bonneville reservoir had the second highest mean temperature of 69.80°F on August 25th and August 27th. A note on the lower Snake River Water Temperature Graph: The mean water temperature data from these reports comes from the USGS Current Conditions for Washington State and the 10-year average water temperature data comes from the Fish Passage Center. USGS began recording water temperatures at Ice Harbor and Lower Monumental on June 16, 2021, Little Goose on June 19, 2021, and Lower Granite on June 18, 2021. Although we are not able to compare spring water temperatures to summer water temperatures, we can see June temperatures rising above the 10-year average and all water temperatures in the lower Snake River are above 60°F.

III. WEEKLY HIGH TEMPERATURES: 8/25-8/31

On the lower Snake River, all reservoirs registered high temperatures above 68°F for at least part of the past week. The reservoir behind the Ice Harbor Dam registered the highest temperature at 71.42°F - significantly above the level that coldwater fish require. Lower Monumental Dam’s reservoir had the second-highest temperature at 70.52°F.

On the lower Columbia River, all reservoirs registered high temperatures above 69°F for multiple days. The reservoir behind the John Day Dam had the highest temperature this week at 71.24°F. The Bonneville Dam had the second-highest temperature at 71.16°F.

Temperature data included in these reports come from the USGS Current Conditions for Washington State and the Fish Passage Center. Graphs and tables were assembled by SOS Staff.

IV. 2021 Snake River wild salmon and steelhead returns - so far.

As we near the conclusion of the Hot Water Report for 2021, this week we present the latest information regarding the status of native fish returns for Snake River (1) wild Spring/Summer Chinook, (2) wild steelhead, and (3) wild/natural sockeye. As part of this review, we will look at how the current numbers of returning adults compare to established recovery goals - the adult returns deemed necessary to recover these populations and remove them from the Endangered Species Act list.

In summary - Snake River salmon and steelhead populations have been in a steady decline for many years, they are returning this year at some of their lowest levels ever. They are teetering today on the precipice of extinction. Without immediate and meaningful conservation actions, we will lose these populations forever.

The health of these populations has plummeted over time from historic levels that were once in the hundreds of thousands or millions, depending on the particular population. The four federal dams and their reservoirs on the lower Snake River in southeast Washington State continue to be a main obstacle to recovery. The rising temperatures caused by these stagnant reservoirs and reductions in snowpack in recent decades due to climate change are contributing to lower survival and reproductive success for already endangered salmon and steelhead. As a result, wild Snake River Chinook, steelhead, and sockeye are much closer to extinction than established recovery goals. Despite spending billions of dollars on recovery projects, long-term trends for these populations have left these species at grave risk of extinction. Below, you will find the high-end recovery goals for wild Snake River salmon and steelhead that have been set to reflect the healthy run levels that returned to Idaho in the 1950s - before the dams were constructed. These goals represent self-sustaining, harvestable populations that currently available, high quality habitat in the Snake River Basin upstream from the dams could support. Restoring abundant populations will allow salmon to once again to play their essential role as a keystone species, feeding countless other animals and plants, and supporting Northwest cultures and economies. Restoring the lower Snake River through dam removal is our very best river and salmon restoration opportunity anywhere in the nation today. And, for the survival and recovery of Snake River populations, dam removal is an essential piece of a larger recovery strategy. Scientists predict it can regularly produce up to and more than a million adult salmon and steelhead entering the mouth of the Columbia River annually in the spring and summer months.

Snake River Wild Salmon Returns as of 8/24/2021

Spring/Summer Chinook

• Endangered Species Act Status: Threatened (listed in 1992)
• Historical Annual Return: Over 2 million
• Recovery Goal: Escapement of 127,000 wild adults per year
• Recent Returns: 7,062 (counted at the Lower Granite Dam)

Spring/summer chinook were once the Pacific Northwest’s most widely distributed and abundant salmon, numbering in the millions. The Salmon River alone produced 39 percent of the spring chinook and 45 percent of the summer chinook in the entire Columbia River Basin.¹ Currently, an estimated 7,062 wild spring/summer Chinook have returned from the ocean to their upriver spawning grounds in Idaho.

In 2020, just 8,556 wild spring/summer Chinook returned to Idaho. Compared to the 4,152 wild Chinook that returned in 2019, this may seem like a strong improvement and a sign of a population on the right track. However, the oscillating nature of salmon returns means that variation from one year to the next is normal. The recovery goal for wild spring/summer chinook calls for a 10-year average of 127,000 returning fish. Notably, the 2020 adult return is less than 7% of this recovery target, and the 10-year average is just 11% of that target.

Steelhead

• Endangered Species Act Status:Threatened (listed in 1997)
• Historical Annual Return:Over 1 million
• Recovery Goal:Escapement of 104,500 wild adults per year
• Recent Returns:440 (counted at the Lower Granite Dam)

Historic runs of steelhead to the Snake River Basin were estimated to be approximately one million fish annually.¹ The Snake River and its tributaries produced 55 percent of summer steelhead in the entire Columbia River basin.¹ However, wild steelhead returns have declined over the past years compared to their recovery goal of 104,500 wild steelhead returns per year. During the 2018-2019 run, only 8,287 wild steelhead returned to Idaho, just 8% of returns from the 1950s. The 10 year average for steelhead is 28,911, which is 28% of the recovery goal. Now, an estimated 440 of wild steelhead have returned from the ocean to their upriver spawning grounds in Idaho. Snake River steelhead are in critical decline today. Without urgent effective conservation measures, they will go extinct.

Sockeye

• Endangered Species Act Status: Endangered (listed in 1991)
• Historical Annual Return: Over 100,000+/yr to central Idaho’s high mountain lakes
• Recovery Goal: 9,000 wild adults per year to the Stanley Basin
• Recent Returns: 1 (counted at the Lower Granite Dam)

Sockeye salmon spawn in the glacial lakes of the Sawtooth Valley and, historically, a few other high elevation lakes in central Idaho.¹ Historic runs to Idaho’s high mountain lakes used to be 100,000+ sockeye per year but have also severely declined over the years.¹ In the early 1990s, there were no adult returns for sockeye salmon due to harmful conditions the lower Snake River dams produced and as a result the sockeye were first listed as an endangered species under the Endangered Species Act in 1991.²

The 10-year average for sockeye returning to the Stanley Basin in central Idaho is just 94 fish, 1% of the recovery goal of 9,000 wild sockeye per year. As of August 24, just 1 sockeye has returned to Idaho. This year, Idaho Fish and Game are trapping the sockeye that arrive at Lower Granite Dam and hauling them by truck to an Idaho Fish hatchery as a precautionary conservation measure, given the extremely low returns, resulting in 28 sockeye that have been trapped and hauled.³

Since the completion of the Columbia Basin’s last major dams on the lower Snake River in the 1970s, salmon survival rates have fallen far short of minimum levels every year. This trend continues today. Earlier this year, The Nez Perce Tribe’s Department of Fisheries Resources Management presented their latest analysis: “Snake Basin Chinook and Steelhead Quasi-Extinction Threshold Alarm and Call to Action.” This report shows that nearly half of the wild spring chinook populations in the Snake River Basin have crossed a critical threshold known as the Quasi-Extinction Threshold (QET), signaling they are nearing extinction and without immediate intervention, many will not persist. In addition, the river’s steelhead populations also face alarming threats to their continued existence. QET means 50 or fewer spawners on the spawning grounds for 4 consecutive years, and the QET also signifies that adult salmon abundance in a population nearing absolute extinction and the probability of recovery is low without substantial intervention.⁴

According to Dave Johnson, Manager of the Nez Perce Tribe’s Department of Fisheries Resources Management, the chinook salmon populations are “declining about 19% each year, and it is predicted that by 2025, 77% of spring and summer chinook populations in the Snake River Basin are predicted to be at or below the Quasi-Extinction threshold in the Snake River Basin.”⁵ The 77% of the natural-origin spring and summer chinook populations in the Snake River Basin will be closer to extinction within the next 5 years.⁴

The department also found that the summer steelhead populations are declining by approximately 18% each year and predictions show that by 2025, 7 (44%) summer steelhead populations are predicted to drop below 50 spawners.^₄

This year’s record low numbers of steelhead returns to the Columbia River and Snake River has caused Oregon and Washington’s Departments of Fish and Wildlife to adopt new immediate protective measures.⁶ ODFW announced that Oregon rivers connected to the Columbia system will be closed to steelhead retention from Wednesday, September 1st, to December 31st.⁶ Specifically, the lower Umatilla, Deschutes, and John Day Rivers including the Walla Walla River (starting at the Oregon-Washington border) will be closed to steelhead fishing.⁷

WDFW commissioners plan on shutting down steelhead fishing from the Snake River delta at Burbank to the Idaho-Washington border at Clarkston.⁶ The department has not yet released an official announcement regarding measures to protect wild steelhead runs on the Walla Walla River on the Washington side of the border.⁶

The Idaho Fish and Game Commission has not released the measures they plan to implement; however, “fisheries managers in Idaho are working on steelhead recommendations that will be forwarded to the Idaho Fish and Game Commission for consideration this week”⁸ Idaho Fish and Game officials stated they plan to implement measures that are “designed to protect threatened wild fish and ensure hatcheries meet spawning goals.”⁸

Unprecedented high water temperatures in the Pacific Northwest are putting Snake River salmon and steelhead runs at even greater risk and low returns of wild steelhead directly impacts local anglers, businesses, commercial, Tribal fishing economies, and communities across the Northwest.

Salmon and steelhead populations support thousands of fishing jobs throughout the Northwest; however, with the lower Snake River four dams in place, declining returns of these emblematic fish can be expected to continue. Relying on temporary protective measures is not enough to bring salmon and steelhead populations into abundance.

References:
1. The Salmon Community’s View: The status of wild salmon and steelhead populations in the Columbia and Snake River Basin (2016)
I2. daho Fish and Game: Sockeye Salmon(2005)
3. SOS: A look at Snake River Wild Salmon & Steelhead Returns(August 4, 2021)
4. Snake Basin Chinook and Steelhead Quasi-Extinction Threshold Alarm and Call to Action (2021)
5. Salmon and Orca Summit 2021(July 8, 2021)
6. Union-Bulletin: Officials limit steelhead angling in Eastern Washington, Oregon as fish census plummets (August 30, 2021)
7. Oregon Department of Fish and Wildlife: Emergency fishing closures in Deschutes, other mid-Columbia tributaries begin Sept. 1 due to low steelhead returns (August 27, 2021)
8. The Lewiston Tribune: Officials plan to close steelhead fishing(August 28, 2021)

LINKS TO RECENT NEWS:

• Idaho States Journal: Steelhead numbers bad, again (August 26, 2021)
• Idaho Capital Sun: The content of Simpson’s salmon plan has been at forefront. But its character may matter even more. (August 24, 2021)

 Martha Campos is the Hot Water Report Coordinator with Save Our wild Salmon this summer while she resides on Kizh/Tongva ancestral lands in California. Martha holds a BA from the University of California, Davis in Native American Studies (and two minors: Environmental Policy, Analysis, and Planning and Climate Science and Policy) and is a queer, non-binary person of color with ancestral roots in Mexico.

I. INTRODUCTION

Welcome to Save Our wild Salmon’s Hot Water Report 2021, Week 12, our final issue for this summer!

This summer, we’ve provided updates on real-time water temperatures in the lower Snake and Columbia River reservoirs via graphs and analyses, a report on the highest weekly water temperature at the forebay/reservoir of each dam, and the status of adult returns for the different salmon and steelhead populations as they return to their natal spawning grounds. We heard first-hand from scientists and other experts about challenges facing the Columbia and Snake rivers - and the opportunities we have to restore health to these rivers, and help recover healthy, resilient fish populations and the many benefits they deliver to the Northwest’s culture, economy, and ecology.

The once-abundant anadromous native fish populations that call the Columbia-Snake River Basin home are struggling to survive in large part due to multiple harmful effects caused by the system of federal dams and reservoirs. The federal hydro-system creates conditions that harm and kill both juvenile and adult salmon and steelhead, including by elevating water temperatures in large, stagnant reservoirs in the summer months. As cold water species, these fish begin to suffer harmful effects when water temperatures exceed 68° Fahrenheit. The longer and higher temperatures rise above 68°F, the greater the harm, including migration disruption, increased metabolism, increased susceptibility to disease, reduced fecundity or reproductive potential, suffocation (warm water carries less oxygen) and in the worst case - death.

These harmful hot water episodes above 68 degrees in the Columbia and Snake rivers are increasing in duration, frequency, and intensity. Our changing climate is making an already bad situation for the Northwest’s emblematic fish even worse. Our region and nation must take urgent action to lower these high temperatures or scientists tell us that we will lose these species forever. Restoring a freely flowing lower Snake River by removing its four federal dams is almost certainly our only option for lowering water temperatures in this 140-mile stretch of river in southeast Washington State. Restoring the Snake River is one essential element of what must be a larger regional strategy to protect and rebuild healthy, abundant salmon and steelhead populations in order to benefit other fish and wildlife populations, including critically endangered Southern Resident orcas, to uphold our nation’s promises to Native American tribes, and to ensure prosperous communities across the Northwest.

The Hot Water Report is a joint project of the Save Our wild Salmon Coalition, Washington Sierra Club, Columbia Riverkeeper, Idaho Rivers United, National Wildlife Federation, Snake River Waterkeeper, Northwest Steelheaders, Defenders of Wildlife, and Endangered Species Coalition.

II. READING THE DATA - Lower Snake and Columbia River Temperatures

The daily mean temperature at the four reservoir forebays (immediately upstream from each dam) in the lower Snake River (above) and the lower Columbia River (below) for 2021 is represented with solid lines and their 10-year average (2011-2021) temperatures with dashed lines of the same color. The dotted horizontal line across the graph represents the 68°F “harm threshold” for adult and juvenile fish. Salmon and steelhead suffer harmful effects when water temperatures exceed 68° Fahrenheit. The longer temperatures remain above 68°F and the higher the temperatures rise above 68°F, the more severe the effects.

Fortunately, water temperatures have begun to drop but at this time they still remain high - and harmful - for salmon and steelhead in the lower Snake and lower Columbia River reservoirs: On the lower Snake River, the waters in the Lower Monumental reservoir had the highest mean temperatures of 68.72°F on September 1st. The Little Goose reservoir had a mean temperature of 67.28°F, almost one degree below the harmful threshold (68°F). At this time the USGS has not released water temperature data from the lower Snake River reservoirs from September 2nd to September 7th. At this point, we expect the current temperatures reflected in the graph to continue and then cool toward the middle of September. So far this summer, all four reservoirs exceeded 68°F this summer for at least 40 to 67 days. The Lower Monumental reservoir has exceeded 68°F for at least 67 days. The Little Goose reservoir has exceeded 68°F for at least 66 days this summer.

Temperatures in 3 out of 4 lower Columbia River reservoirs have recently flattened out above 68°F. All reservoirs continue to exceed 68°F by between one degree; this will probably be the case through the middle of September. On September 5th, The Dalles reservoir had the highest mean temperature of 69.26°F. The John Day reservoir also had a highest mean temperature 69.26°F, on September 7th. The Bonneville reservoir had the second highest mean temperature of 68.90°F, on September 7th.

A note on the lower Snake River Water Temperature Graph: The mean water temperature data from these reports comes from the USGS Current Conditions for Washington State and the 10-year average water temperature data comes from the Fish Passage Center. USGS began recording water temperatures at Ice Harbor and Lower Monumental on June 16, 2021, Little Goose on June 19, 2021, and Lower Granite on June 18, 2021. Although we are not able to compare spring water temperatures to summer water temperatures, we can see June temperatures rising above the 10-year average and all water temperatures in the lower Snake River are above 60°F.

III. Legal Conflicts in the lower Snake River
by Miles Johnson, Columbia Riverkeeper, Senior Attorney

Another summer of brutally hot water, low salmon returns, and graphic fish kills points to an uncomfortable conclusion: the Columbia-Snake river hydro-system as it is currently operated by BPA and the Army Corps is incapable of complying with the Endangered Species Act and the Clean Water Act. In other words, the status quo is not only not working, it’s not even legal. Let’s cut through the fog of legal citations and lawyer-speak and look at what two of our nation’s most important environmental laws mandate with respect to Columbia Basin salmon. The Endangered Species Act essentially prohibits federal agencies (like BPA and the Army Corps) from making species go extinct. But that is precisely what the dams are doing, most dramatically with respect to Snake River salmon and steelhead. The rate at which Snake River fish survive their journeys down, and then back up, the dammed river is simply too low to prevent extinction or achieve recovery. That problem, in a nutshell, is why courts have repeatedly rejected federal plans (called “biological opinions” in ESA-speak) attempting to justify the dams’ compliance with the Endangered Species Act. Some backers of the Snake River dams have acknowledged this reality and asked past presidential administrations to remove salmon from the Endangered Species List. BPA and the Army Corps have taken a less direct approach: repeatedly putting forward plans that maintain the status quo but clearly violate the ESA, and defend those plans in court while salmon and steelhead inch closer to extinction. As multiple federal judges have hinted, only a major overhaul of the hydrosystem and its status quo operations will bring BPA and the Army Corps into compliance with the Endangered Species Act.

As required by the Clean Water Act, Oregon and Washington have set limits on Columbia and Snake river water temperatures to keep these rivers cool enough for salmon and steelhead. A recent report by the U.S. Environmental Protection Agency (EPA) details how dams on the Snake River make the water too hot for salmon and exceed the Clean Water Act’s temperature limits. The Army Corps has fought for decades to keep the dams from being regulated under the Clean Water Act, and there’s a reason: dams on the Lower Snake River will continue violating water quality standards absent profound changes to their configuration and operation. Those changes may be coming, however, as EPA and the Washington Dept. of Ecology seem poised to issue new Clean Water Act permits that will force the Army Corps to consider ways to keep the rivers cool.

IV. Urgency to remove the four lower Snake River Dams

Historically, abundant Snake and Columbia River salmon and steelhead delivered vast cultural, economic, nutritional, and ecological benefits to the people and fish and wildlife of the Pacific Northwest. Not long ago, the Columbia Basin would experience millions of adult salmon and steelhead that flooded into the Columbia River Basin each year. Chinook, or King salmon, are the largest and richest of the salmonid species. They are also notably the primary food source (roughly 80 percent of their overall diet) of the critically endangered Southern Resident orcas. Columbia Basin chinook can spend five or more years in the Pacific Ocean before they return to freshwater to spawn.

Snake and Columbia Basin fish, however, are in crisis - thirteen distinct populations in the Columbia Basin are at risk of extinction today. The health of these populations has plummeted over time from historic levels that were once in the hundreds of thousands or millions, depending on the particular population. Snake River salmon and steelhead populations have been in a steady decline for many years; they are returning this year at some of their lowest levels ever.

Climate change increases the urgency to remove these four dams and restore this river. The frequency, duration, and intensity of high harmful water temperatures in the four lower Snake River’s reservoirs have been steadily increasing within the last several decades – with increasingly devastating impacts on out-migrating juvenile fish and adults returning from the Pacific Ocean to spawn. In 2015, for example, due to the combined effects of extremely hot air and water temperatures, low 2014-15 snowpack that led to low 2015 runoff, and the presence of dams and their reservoirs, at least 96% of endangered returning adult Snake River sockeye salmon died - a species with an already low population level - during their upriver migration through the lower Columbia and Snake Rivers.

This summer, we experienced another high water temperature in the lower Snake River. From June to September, all four lower Snake River’s reservoirs had waters above 68°F for over 40 to 67 days. The reservoir behind the Ice Harbor Dam registered the highest temperature we have seen this summer at 73.22°F on July 18, 2021. Lower Monumental Dam’s reservoir had a high temperature of 73.04°F on August 14, 2021, and the reservoir registered above 68°F for 67 days. The Little Goose Dam’s reservoir also had a high temperature of 73.04°F on June 27, 2021. Finally, from August 3 to August 4, 2021, the Lower Granite Dam’s reservoir had a high temperature of 71.96°F. The longer and higher temperatures rise above 68°F, the greater the harm, including disruption in their migration, increased metabolism, increased susceptibility to disease, reduced fecundity or reproductive potential (by reducing egg viability), suffocation, and in the worst case - death.

Rising temperatures in the four lower Snake River’s reservoirs along with climate change impacts have resulted in lower survival and reproductive success for endangered salmon and steelhead. Earlier in July, Columbia Riverkeeper released video footage and imagesthat show heat-stressed sockeye salmon returning to the Columbia and Snake rivers. These sockeye have large, open lesions and fungus and it is predicted that these sockeye would not be able to spawn, and will instead die of heat stress and disease. As of August 24, just 1 sockeye has returned to Idaho. This year, given the extremely low returns of sockeye, the Idaho Fish and Game are trapping the sockeye that arrive at Lower Granite Dam and hauling them by truck to an Idaho Fish hatchery as a precautionary conservation measure, resulting in 28 sockeye that have been trapped and hauled.

This summer, we have seen low numbers of chinook, steelhead and sockeye returns to the Columbia River and Snake River. We cannot let low returns of salmon and steelhead continue as extinction of these fish are near. We have an opportunity to make critical changes that ensure the survival of wild salmon and steelhead, and increase the resilience of rivers and our climate, and meet the needs of people and communities across the Pacific Northwest. Upon decades worth of scientific research, it is clear that restoring the lower Snake River will dramatically lower water temperatures and restore 140-mile of the river and 14,000+ acres of riparian habitat and again offer diverse habitats found in living rivers, including additional cold water refugia currently lost as a result of these reservoirs today.

Throughout our 2021 Hot Water Reports, we have identified key solutions and strategies to salmon recovery and restoring the lower Snake River. To protect, restore, and reconnect the freshwater habitats that salmon and steelhead depend upon, a few of the solutions and strategies include:

• Address the harmful effects (altered hydrograph, hot river temperatures, increase of predators, etc.) created by the federal hydro-system and now made worse by a changing climate in order to increase the resilience of these river systems and the fish themselves.
• Currently, help aid the migration of endangered salmon and steelhead and increase their survival in the near-term by using two methods of spill and reservoir drawdown. The plaintiffs view the requested injunction as “an emergency stop-gap measure and not enough alone to prevent extinction.” The best available science strongly supports lower Snake River dam removal as necessary to protect these populations from extinction and restore them to abundance.
• Help ensure that we meet our Treaty obligations to Native American Tribes in the Columbia Basin and currently support members of the Confederated Tribes of the Umatilla Indian Reservation Youth Leadership Council in calling on President Biden to remove the four lower Snake River dams and bring long overdue Tribal Justice to Native Nations.
• Fully replacing the Lower Snake River hydrosystem energy dams with carbon-free, renewable, affordable, and salmon-friendly alternatives as well as help support and maintain an affordable energy system for Northwest people and communities. NW Energy Coalition’s 2018 Lower Snake River Dams Power Replacement Study shows convincingly that replacing the lower Snake River dams with a balanced portfolio of clean, renewable energy including solar, wind, energy efficiency, and storage is feasible, reliable, and affordable.
• Strengthen our region's transportation infrastructure and create more jobs. Dam removal is an opportunity to make smarter investments in rail, port and other transportation infrastructure to ensure farmers can continue to affordably move their goods to market. We have the opportunity to expand recreation, tourism, clean energy and transportation industries that can create thousands of family-wage jobs for people living along the Snake River.

Restoring the lower Snake River is our very best opportunity to restore endangered salmon and steelhead to abundance in the Northwest. Removing the four lower Snake River Dams will restore the Northwest’s native fish, help feed starving orcas, will save American taxpayer and Northwest energy consumer dollars; create thousands of jobs regionally and invest in communities; and sustain a clean, reliable and affordable energy system. Removing these costly dams and restoring this historic river and its wild fish is our nation’s greatest river and salmon restoration opportunity today.

LINKS TO RECENT NEWS:

• Inlander: Salmon face deadly hot waters along Columbia and Snake rivers as the call for dam removal grows (September 2, 2021)
• Seattle Times: Baby J pod orca ailing; whale-watch tours ordered to keep away (September 3, 2021)
• Seattle Times: Lower Snake River irrigators propose two-dam drawdown, breaking with some farmers and bargers (September 7, 2021)
• ​​Past Hot Water Reports are archived here: Hot Water Reports - Compiled

 Martha Campos is the Hot Water Report Coordinator with Save Our wild Salmon this summer while she resides on Kizh/Tongva ancestral lands in California. Martha holds a BA from the University of California, Davis in Native American Studies (and two minors: Environmental Policy, Analysis, and Planning and Climate Science and Policy) and is a queer, non-binary person of color with ancestral roots in Mexico.

I. INTRODUCTION

Welcome to Save Our wild Salmon’s Hot Water Report 2022.

During the summer, this weekly report provides an update on real-time water temperatures in the lower Snake and Columbia River reservoirs via graphs and analyses, a summary on the highest weekly water temperatures at the forebay/reservoir of each dam, and the status of adult returns for different salmon and steelhead populations as they make their way back to their natal spawning grounds. We’ll hear first-hand from scientists, Tribal members, fishing guides, advocates, and other experts about the challenges facing the Columbia and Snake rivers - and our opportunities to improve and restore them - in order to recover healthy, resilient fish populations and the benefits they deliver to the Northwest’s culture, economy, and ecology.

The once-abundant anadromous fish populations of the Columbia-Snake River Basin are struggling to survive today in large part due to multiple harms caused by the system of federal dams and reservoirs. The federal hydro-system creates conditions that harm and kill both juvenile and adult fish, including by elevating water temperatures in large, stagnant reservoirs in the summer months. These cold-water fish begin to suffer harmful effects when water temperatures exceed 68° Fahrenheit. The longer and the higher these temperatures rise above 68°F, the greater the harm, including: migration disruption, increased metabolism, increased susceptibility to disease, reduced reproductive potential (by reducing egg viability), suffocation (warm water carries less oxygen), and in the worst case - death.

Today, these harmful hot waterepisodes above 68°F in the Columbia and Snake Rivers are increasing in duration, frequency, and intensity. Our changing climate is making a bad situation for the Northwest’s iconic fish worse. Our region and nation must take urgent action to maintain cool water temperatures - or we will lose these species forever. Restoring a freely flowing lower Snake River by removing its four federal dams is our only feasible option to address high water temperatures in this 140-mile stretch of river running through southeast Washington State. Restoring the Snake River is one essential element of what must be a larger regional strategy to protect and rebuild healthy, abundant salmon and steelhead populations in order to benefit other fish and wildlife populations, including critically endangered Southern Resident orcas, to uphold our nation’s promises to Native American tribes, and to ensure prosperous communities across the Northwest.

The Hot Water Report 2022 is a joint project of the Save Our wild Salmon Coalition, Columbia Riverkeeper, American Rivers, Endangered Species Coalition, Environment Washington, Idaho Conservation League, Idaho Rivers United, Idaho Wildlife Federation, National Resource Defense Council, National Wildlife Federation, Nimiipuu Protecting the Environment, Northwest Sportfishing Industry Association, Sierra Club, Snake River Waterkeeper, Spokane Riverkeeper, Wild Orca, and Wild Steelhead Coalition.

 II. READING THE DATA - Lower Snake and Columbia River Temperatures

Introduction: The daily mean temperature at the four reservoir forebays (immediately upstream from the dam) in the lower Snake River (above) and the lower Columbia River (below) for 2022 is represented with solid lines and their 10-year average (2012 - 2022) temperatures with dashed lines of the same color. The dotted line across the graph represents the 68°F “harm threshold” for adult and juvenile fish. Salmon and steelhead begin to suffer harmful effects when water temperatures exceed 68° Fahrenheit. The longer temperatures remain above 68°F and the higher the temperatures rise above 68°F, the more severe the potential effects, including: increased metabolism, increased susceptibility to disease, reduced reproductive potential, and/or death (see Issue 1 for more detailed information).

Discussion: Since April, temperatures in the lower Snake River and the lower Columbia River reservoirs have steadily moved upward. During April and May, trends have tracked closely with the 10-year average. In June, however, water temperatures dropped considerably below this average. This was good for cold-water species like salmon and steelhead, but since July, temperatures have reached and exceeded the 68°F “harm threshold” in the reservoirs on the lower Snake and Columbia River. Below, we present the highest temperatures for each reservoir on the lower Snake and Columbia River. 

A note on data information: The mean water temperature data from these reports comes from the USGS Current Conditions for Washington State and the 10-year average water temperature data comes from the Fish Passage Center. There is no available data for Lower Monumental 10-year average water temperature. Graphs and tables were assembled by SOS Staff.

III. WEEKLY HIGH TEMPERATURES: 8/2-8/8

Harmful water temperatures in the lower Snake River reservoirs: This week, all reservoirs exceeded 68 degrees. The Little Goose Dam reservoir has spent 25 days above 68°F and similarly, the Ice Harbor Dam spent 23 consecutive days above 68°F. The reservoir behind Ice Harbor Dam registered the highest temperature at 71.96°F on August 4th. The waters behind Lower Monumental Dam and Little Goose Dam registered the second highest temperature at 70.34°F.

On the lower Columbia River, all reservoirs peaked over 68°F. The reservoirs behind the John Day Dam and The Dalles dam registered the highest temperature: 71.96°F.

 IV. Salmon and steelhead need healthy oceans and healthy rivers (of course!)

Wild salmon and steelhead are long-migrating fish that spend significant parts of their lives in freshwater and in saltwater ecosystems. The condition of each - saltwater and freshwater - affects fish survival. However, there’s a misleading narrative advanced by defenders of the status quo that ocean conditions, rather than the four lower Snake dams, are the real obstacle to recovering healthy, abundant populations of Snake River salmon and steelhead. This is false - Northwest salmon and steelhead all swim in the same ocean, but the mortality rates they experience in freshwater increase significantly with the number of dams and reservoirs they encounter. Specifically, endangered Snake River salmon and steelhead have to cross eight dams and reservoirs to reach the ocean and then again as they return to their spawning grounds. And these fish suffer from the highest mortality rates, and lowest smolt-to-adult return ratios, compared to other fish that spawn lower in the watershed and encounter fewer dams and reservoirs. 

Salmon and their ecosystems:

Ocean conditions do play a significant role affecting salmon and steelhead survival. When ocean conditions are good (abundant food availability for salmon and steelhead to eat), salmonid survival in the ocean increases, and we see increased survival of juvenile fish as they enter the ocean and increased adult salmon returns back into the Columbia-Snake Basin. When ocean conditions decline (reduced food availability), we often see adult returns (survival) decline too. The ocean has a long-running and well-documented cyclic pattern of good conditions followed by bad conditions. 

It should surprise no one that the condition of freshwater ecosystems also significantly affect salmon and steelhead survival and reproduction. In the Columbia-Snake Basin, the construction of the federal hydro system - the dams and their reservoirs - has profoundly degraded available fish habitat and also profoundly reduced access to historic habitat. The federal hydro system in the Columbia Basin is far and away the largest single source of human-caused mortality for salmon and steelhead. Dams and reservoirs destroy spawning and rearing habitat; they warm waters, slow currents, increase energy expenditures by young migrating fish, significantly increase predation by invasive and other fish that thrive in these stagnant warm-water reservoirs. The more dams and reservoirs that these fish encounter in their life, the greater their mortality. And, importantly, a significant number of dams completely block access to once-highly productive habitat in the Columbia and Snake Rivers and their tributaries.

In a free flowing river, smolts ride the cold current quickly to the ocean. With dams and reservoirs, they need to swim to the ocean. This takes much longer and requires lots of energy that they then don’t have for reserves when they arrive at the ocean, if they arrive at the ocean. This issue of stagnant waters on one more way that dams and reservoirs harm and kill salmon and steelhead.

Dams are the major case of salmon and steelhead deaths:

The science demonstrates clearly that salmon and steelhead who live in the same Pacific Ocean have drastically different mortality rates depending on how many dams and reservoirs they encounter on their journey to and from the ocean. Fish who encounter four dams or less return at comparatively higher levels and are far more able to sustain themselves. Salmon and steelhead in the Snake River, however, encounter eight dams and reservoirs and are not sustaining themselves today.

For Snake River fish, the dams and their reservoirs can kill up to 70% of out-migrating juvenile fish before they ever reach the ocean. Since Snake and Columbia Basin salmon and steelhead swim in the same ocean, the cause of the mortality of Snake River fish is not found in ocean waters. The Snake River salmon and steelhead mortality rates increase due to high number of dams - and hot water reservoirs - they must pass.

Smolt-to-Adult Ratios (SARs) decrease as the number of dams/reservoirs fish encounter increase.

How do we know dams are the primary source of mortality for Snake River fish? Let’s look at the smolt-to-adult ratio of these populations. Smolt-to-adult ratio - or SAR - reflects the percentage of ocean-bound juvenile fish that return as adults to spawn in freshwater.

SAR is crucial as it’s the only metric that captures most of the cumulative impacts of the hydro system on salmon and steelhead, telling us how sustainable the returns of adults are over time. This is critical because even if high-quality habitats produce a lot of smolts, the population can only sustain if those smolts can make it out to the ocean and survive to return and spawn as adults at sufficient SAR.¹

Before the last three Snake River dams were completed in the mid-1960s (Ice Harbor was in place, as were the Columbia dams), SAR for Snake River spring/summer Chinook salmon ranged from 3.5 to 6.5 percent (average 4 percent from 1964-1968).² 

However, over the last 25 years (after the construction of the lower Snake River dams), SARs for Snake River salmon and steelhead have fallen consistently below 2 percent despite restrictions and closures of modern fisheries, and massive investments in Snake River Basin habitat restoration and juvenile fish passage systems at the lower Snake River dams.² This decline in SARs below 2 percent represents a trajectory toward extinction because not enough smolts survive to return and spawn as adults.²

Rebuilding Snake River salmon and steelhead populations will require increasing their SAR. The Northwest Power and Conservation Council determined long ago that a SAR of 4 to 6 percent (that is, for every 100 smolts that head out to the ocean, 4 to 6 adults must successfully return to spawn) is needed to recover and maintain healthy, harvestable populations.² Further, scientists have concluded that removing the four lower Snake River dams allows the fish to consistently achieve 4 to 6 percent SAR.²

Restoring the Snake River and its fish:

While both ocean and freshwater habitat conditions affect salmon survival and recovery, there is one big difference. Our decisions and policies - past, present and future - have a huge influence on the condition of freshwater habitat. By restoring the Snake River through dam removal, we will significantly increase salmon survival in freshwater and significantly decrease mortality caused by the dams and their reservoirs. 

Further, the higher the quality of the freshwater habitat - colder waters, faster currents, less predation, and less dam/powerhouse encounters - the better the condition of young out-migrating salmon and steelhead when they arrive at the ocean. The better condition that juvenile fish are when they arrive at the ocean - whether its conditions are good or poor - the higher the survival of the fish and the higher the eventual returns of adults a few years later.

The science is clear: The four dams on the lower Snake River are the single-biggest source of human-caused mortality for the salmon and steelhead that call the Snake River Basin home. And removing the lower Snake River dams is the single most important action we can take to recover these fish and improve the quality of freshwater rivers and streams and help them survive their time in the ocean - regardless of its condition at any given time.

References:
1. Trout Unlimited: What is a smolt-to-adult ratio and why is it important?
2. Trout Unlimited: Is it possible to recover salmon and steelhead without removing the dams?

LINKS TO RECENT NEWS:

• National Oceanic and Atmospheric Administration: Rebuilding Interior Columbia Basin Salmon and Steelhead (Draft, July 2022) PDF
• Water Biology and Security Journal: A review of potential conservation and fisheries benefits of breaching four dams in the Lower Snake River (March 2022) PDF
• Seattle Times: White House weighs in on Lower Snake River dam breaching in unusual power play (July 12, 2022)
• NWNews: Federal report recommends breaching Lower Snake River dams to restore salmon (July 12, 2022)
• Tri-City Herald: ‘Who are we without salmon?’ Tribes gather along dammed Snake River to call for action (August 10, 2022)
• Everett Herald LTE: Snake River dams’ power easily replaced (August 10, 2022)
• Everett Herald LTE: Snake dams’ contributions were overstated (August 9, 2022)
• Lewiston Tribune: Salmon and dam talks get another year (August 5, 2022)
• The Seattle Times: New deal seeks to extend truce in court battle over Columbia River salmon (August 5, 2022)
• OPB: How a federal agency is contributing to salmon’s decline in the Northwest (August 4, 2022)

Martha Campos is the Hot Water Report Coordinator with Save Our wild Salmon this summer while she resides on Kizh/Tongva ancestral lands in California. Martha holds a BA from the University of California, Davis in Native American Studies (and two minors: Environmental Policy, Analysis, and Planning and Climate Science and Policy) and is a queer, non-binary person of color with ancestral roots in Mexico.

I. INTRODUCTION

Welcome to Save Our wild Salmon’s Hot Water Report 2022.

During the summer, this weekly report provides an update on real-time water temperatures in the lower Snake and Columbia River reservoirs via graphs and analyses, a summary on the highest weekly water temperatures at the forebay/reservoir of each dam, and the status of adult returns for different salmon and steelhead populations as they make their way back to their natal spawning grounds. We’ll hear first-hand from scientists, Tribal members, fishing guides, advocates, and other experts about the challenges facing the Columbia and Snake rivers - and our opportunities to improve and restore them - in order to recover healthy, resilient fish populations and the benefits they deliver to the Northwest’s culture, economy, and ecology.

The once-abundant anadromous fish populations of the Columbia-Snake River Basin are struggling to survive today in large part due to multiple harms caused by the system of federal dams and reservoirs. The federal hydro-system creates conditions that harm and kill both juvenile and adult fish, including by elevating water temperatures in large, stagnant reservoirs in the summer months. These cold-water fish begin to suffer harmful effects when water temperatures exceed 68° Fahrenheit. The longer and the higher these temperatures rise above 68°F, the greater the harm, including: migration disruption, increased metabolism, increased susceptibility to disease, reduced reproductive potential (by reducing egg viability), suffocation (warm water carries less oxygen), and in the worst case - death.

Today, these harmful hot waterepisodes above 68°F in the Columbia and Snake Rivers are increasing in duration, frequency, and intensity. Our changing climate is making a bad situation for the Northwest’s iconic fish worse. Our region and nation must take urgent action to maintain cool water temperatures - or we will lose these species forever. Restoring a freely flowing lower Snake River by removing its four federal dams is our only feasible option to address high water temperatures in this 140-mile stretch of river running through southeast Washington State. Restoring the Snake River is one essential element of what must be a larger regional strategy to protect and rebuild healthy, abundant salmon and steelhead populations in order to benefit other fish and wildlife populations, including critically endangered Southern Resident orcas, to uphold our nation’s promises to Native American tribes, and to ensure prosperous communities across the Northwest.

The Hot Water Report 2022 is a joint project of the Save Our wild Salmon Coalition, Columbia Riverkeeper, American Rivers, Endangered Species Coalition, Environment Washington, Idaho Conservation League, Idaho Rivers United, Idaho Wildlife Federation, National Resource Defense Council, National Wildlife Federation, Nimiipuu Protecting the Environment, Northwest Sportfishing Industry Association, Sierra Club, Snake River Waterkeeper, Spokane Riverkeeper, Wild Orca, and Wild Steelhead Coalition.

  II. READING THE DATA - Lower Snake and Columbia River Temperatures

Introduction: The daily mean temperature at the four reservoir forebays (immediately upstream from the dam) in the lower Snake River (above) and the lower Columbia River (below) for 2022 is represented with solid lines and their 10-year average (2012 - 2022) temperatures with dashed lines of the same color. The dotted line across the graph represents the 68°F “harm threshold” for adult and juvenile fish. Salmon and steelhead begin to suffer harmful effects when water temperatures exceed 68° Fahrenheit. The longer temperatures remain above 68°F and the higher the temperatures rise above 68°F, the more severe the potential effects, including: increased metabolism, increased susceptibility to disease, reduced reproductive potential, and/or death (see Issue 1 for more detailed information).

Discussion: Since April, temperatures in the lower Snake River and the lower Columbia River reservoirs have steadily moved upward. During April and May, trends have tracked closely with the 10-year average. In June, however, water temperatures dropped considerably below this average. This was good for cold-water species like salmon and steelhead, but since July, temperatures have reached and exceeded the 68°F “harm threshold” in the reservoirs on the lower Snake and Columbia River. Below, we present the highest temperatures for each reservoir on the lower Snake and Columbia River. 

A note on data information: The mean water temperature data from these reports comes from the USGS Current Conditions for Washington State and the 10-year average water temperature data comes from the Fish Passage Center. There is no available data for Lower Monumental 10-year average water temperature. Graphs and tables were assembled by SOS Staff.

 III. WEEKLY HIGH TEMPERATURES: 8/9-8/15

Harmful water temperatures in the lower Snake River reservoirs: This week, all reservoirs exceeded 68 degrees. The Little Goose Dam reservoir has spent 32 days above 68°F and similarly, the Ice Harbor Dam spent 30 consecutive days above 68°F.

The reservoir behind Ice Harbor Dam registered the highest temperature at 72.14°F on August 14th - significantly above the level that cold-water fish require. The waters behind Lower Monumental Dam registered the second highest temperature at 70.88°F.

This week, on the lower Columbia River, all reservoirs peaked over 68°F. The reservoirs behind the Bonneville Dam registered the highest temperature: 72.14°F.

IV. The Northwest economy will see many benefits from a free-flowing lower Snake River.

Healthy, abundant salmon and steelhead populations not only deliver innumerable ecological benefits to the Northwest, but are also integral to cultures and economies - tribal and non-tribal - of the region. And when salmon disappear, communities suffer due to a lack of opportunity that these fish would otherwise provide. With dam removal, economic opportunities for communities would further be revitalized with the return of 140-miles of free-flowing river and sustainable, fishable salmon and steelhead returns. An economic analysis by ECONorthwest indicated, based on publicly available data, that the “benefits of removal [of the lower Snake River dams] exceed the costs, and thus society would likely be better off without the dams.”¹

In this week’s issue, we explore some of the benefits that a restored Snake River - and salmon and steelhead - will provide to tourism, recreational communities, and fishing communities.

Tourism and Recreation
The economic benefits of restoring the lower Snake River and its salmon and steelhead have been estimated in the billions of dollars thanks to the income it would generate for commercial fishing, and increased recreational fishing.² And, rafting and kayaking on a restored lower Snake would create new business and income for communities from Hells Canyon Dam to the Tri-Cities.

Recreation enhances lives and forms the economic and cultural foundation of many small towns in the Columbia and Snake River Basins.³ In a letter from 40 recreation businesses/organizations to Northwest Senators and Members of Congress seeking restoration of the lower Snake River, the businesses and organizations describe how a restored lower Snake River will expand recreation and tourism opportunities in this region, including rafting, fishing, bird watching, and hunting. “Restoring the lower Snake River will also enhance the future of rural recreation economy along the Clearwater, Grande Ronde, Salmon, and Snake Rivers.”³

The letter states, “We know people are willing to travel long distances and wait years for permits to enjoy high quality wild rivers and scenic canyons. Outdoor recreation is a strong means of transferring wealth from urban to rural communities with every trip imparting $119 per person per day on average. And as more people come to the Northwest to fish and float its rivers, the economy continues to grow: outdoor recreation is currently an $11.5 billion industry in Washington state and a $6.5 billion industry in Oregon. However, the growing trend of fishing season closures in order to protect steadily declining salmon and steelhead populations threatens our industry and livelihoods, including those of our vendors and affiliates who count on seasonal fish returns. Restoring rivers and recovering native fish populations, in contrast, promises both new economic opportunities and improved quality of life.”³

Restoring a free-flowing lower Snake River will help support and revitalize towns across the region. The ECONorthwest economic analysis found that dam removal could result in an increase of almost 100,000 recreational river trips to the Lower Snake River by 2026, and up to 1,000,000 by 2039.

Coastal communities, especially in the San Juan Islands and the Salish Sea, also depend on salmon – that feed a major tourist attraction – the Southern Resident orcas. The whale watching industry brings in over tens of millions of dollars in tourism revenue to many small, coastal communities. The presence of this industry delivers important benefits to these towns, as tourists who come for these adventures also visit local shops, museums, hotels, and restaurants.

An economic analysis by Earth Economics found that “whale watching participants who whale watch from boat-based tours or from terrestrial viewing points in San Juan County support over $216 million worth of economic activity in the Puget Sound Region every year. This activity generates more than $12 million in state and local tax revenue annually and support s over 1,800 jobs.”⁴

In addition, Earth Economics surveyed whale watcher participants to predict their behavior “if orcas decrease in proportion that is expected if the orcas become extinct. In this alternative scenario, 33% of non-local, boat-based whale watching participants said they would no longer choose to visit the Puget Sound Region, equating to an annual loss of $34 million in economic activity, $2.2 million in state and local tax revenue, and 330 jobs.”⁴

The whale watching industry is a powerful way for both locals and tourists to become acquainted with the whales, the threats they face, and the ways that each individual can become an advocate working towards greater protections for these magnificent mammals and other wildlife. Unless chinook salmon populations rebound quickly, we will likely lose the Southern Resident orcas.

Restoring this river and its native fish populations would create new outdoor recreation opportunities, rebuild sport and commercial fisheries, and help to significantly expand tourism opportunities to benefit small-town economies and local businesses throughout the region.

Let’s take a more detailed look at new opportunities in river rafting and kayaking, and in recreational, tribal, and commercial fishing.

A Destination River
A free-flowing lower Snake will provide a destination river for multi-day rafting and kayaking trips, something Washington does not now have. As Senator Murray and Governor Inslee’s draft “Lower Snake River Dams: Benefit Replacement Report” notes, “Stakeholders interviewed for this effort noted that demand for recreation and rafting opportunities through free-flowing rivers is steadily increasing, with the odds of securing a permit to float the Snake River through Hells Canyon decreasing from one in six in 2010 to one in 17 in 2020, and for the Salmon River, the odds have decreased from one in 17 in 2010 to one in 43 in 2020.”⁵

Recreational Fishing
According to Senator Murray and Governor Inslee’s draft “Lower Snake River Dams Benefit Replacement Report,” restoring salmon and steelhead will provide over $1 billion annually in income for recreational fishing industries and support up to 25,000 more jobs.

Tribal Fishing
According to that same draft report, the recovery of these salmon and steelhead stocks would boost annual tribal harvest by at least 29%. Tribal fishing—commercial and subsistence—relied heavily on fisheries for livelihood and economic development but have been gravely impacted by the declines in salmon, steelhead, lamprey, and other native fish species, constrained fishing opportunities, closed seasons, reduced incomes, and eliminated jobs.

Commercial Fishing
Speaking of eliminated jobs, as late as 1978, there were more than 3,000 Washington-based commercial salmon trollers. Today, with depressed salmon populations, there are barely 100—a loss of 6,000 jobs in the fishing fleet and more in onshore businesses providing services, supplies, and equipment to fishermen. Recovery of endangered Snake River salmon would also lead to recovery of our endangered commercial fishing industry.

With salmon and steelhead populations on the brink of extinction, Northwest communities are missing economic and other opportunities that healthy, sustainable salmon populations provide. Restoring the river provides overall economic and environmental benefits to communities across the region.

References:
1. ECONorthwest: Lower Snake River Dams: Economic Tradeoffs of Removal (July 29, 2019) 
2. American Rivers: Our Vision for the Snake River 
3. Snake River Outdoor Recreation Letter (February 23, 2021) 
4. Earth Economics: The whales in our waters: The economic contribution of whale watching in San Juan County (February 15, 2019) 
5. Senator Murray and Governor Inslee's draft "Lower Snake River Dams: Benefit Replacement Report" (June 9, 2021)

 LINKS TO RECENT NEWS:

• The New York Times: Plaintiffs in Long Fight Over Endangered Salmon Hope a Resoluion is Near (August 15, 2022)
• Phys.org: 'If they can't make it, none of them will.' These Idaho salmon may hold key to survival (August 15, 2022)
• The Lewiston Tribune: Guest Opinion: Dugger 'gas lights' fish recovery and dam breaching (August 14, 2022) 
• The Everett Herald: Case is well made for removal of Snake River dams (August 11, 2022)

Martha Campos is the Hot Water Report Coordinator with Save Our wild Salmon this summer while she resides on Kizh/Tongva ancestral lands in California. Martha holds a BA from the University of California, Davis in Native American Studies (and two minors: Environmental Policy, Analysis, and Planning and Climate Science and Policy) and is a queer, nonbinary person of color with ancestral roots in Mexico.

I. INTRODUCTION

Welcome to Save Our wild Salmon’s Hot Water Report 2022.

During the summer, this weekly report will provide an update on real-time water temperatures in the lower Snake and Columbia River reservoirs via graphs and analyses, a summary on the highest weekly water temperatures at the forebay/reservoir of each dam, and the status of adult returns for different salmon and steelhead populations as they make their way back to their natal spawning grounds. We’ll hear first-hand from scientists, Tribal members, fishing guides, advocates, and other experts about the challenges facing the Columbia and Snake rivers - and our opportunities to improve and restore them - in order to recover healthy, resilient fish populations and the benefits they deliver to the Northwest’s culture, economy, and ecology.

The once-abundant anadromous fish populations of the Columbia-Snake River Basin are struggling to survive today in large part due to multiple harms caused by the system of federal dams and reservoirs. The federal hydro-system creates conditions that harm and kill both juvenile and adult fish, including by elevating water temperatures in large, stagnant reservoirs in the summer months. These cold-water fish begin to suffer harmful effects when water temperatures exceed 68° Fahrenheit. The longer and the higher these temperatures rise above 68°F, the greater the harm, including: migration disruption, increased metabolism, increased susceptibility to disease, reduced reproductive potential (by reducing egg viability), suffocation (warm water carries less oxygen), and in the worst case - death.

Today, these harmful hot waterepisodes above 68°F in the Columbia and Snake Rivers are increasing in duration, frequency, and intensity. Our changing climate is making a bad situation for the Northwest’s iconic fish worse. Our region and nation must take urgent action to re-establish cool water temperatures - or we will lose these species forever. Restoring a freely flowing lower Snake River by removing its four federal dams is likely our only option to address high water temperatures in this 140-mile stretch of river running through southeast Washington State. Restoring the Snake River is one essential element of what must be a larger regional strategy to protect and rebuild healthy, abundant salmon and steelhead populations in order to benefit other fish and wildlife populations, including critically endangered Southern Resident orcas, to uphold our nation’s promises to Native American tribes, and to ensure prosperous communities across the Northwest.

The Hot Water Report 2022 is a joint project of the Save Our wild Salmon Coalition, Columbia Riverkeeper, American Rivers, Endangered Species Coalition, Environment Washington, Idaho Conservation League, Idaho Rivers United, Idaho Wildlife Federation, National Resource Defense Council, National Wildlife Federation, Nimiipuu Protecting the Environment, Northwest Sportfishing Industry Association, Sierra Club, Snake River Waterkeeper, Spokane Riverkeeper, Wild Orca, and Wild Steelhead Coalition.

II. READING THE DATA - Lower Snake and Columbia River Temperatures

Introduction: The daily mean temperature at the four reservoir forebays (immediately upstream from the dam) in the lower Snake River (above) and the lower Columbia River (below) for 2022 is represented with solid lines and their 10-year average (2012 - 2022) temperatures with dashed lines of the same color. The dotted line across the graph represents the 68°F “harm threshold” for adult and juvenile fish. Salmon and steelhead begin to suffer harmful effects when water temperatures exceed 68° Fahrenheit. The longer temperatures remain above 68°F and the higher the temperatures rise above 68°F, the more severe the potential effects, including: increased metabolism, increased susceptibility to disease, reduced reproductive potential, and/or death (see Issue 1 for more detailed information).

Discussion: Since April, temperatures in the lower Snake River and the lower Columbia River reservoirs have steadily moved upward. During April and May, trends have tracked closely with the 10-year average. In June, however, water temperatures dropped considerably below this average. This was good for cold-water species like salmon and steelhead, but now, temperatures have reached the 68°F “harm threshold” in the reservoirs on the lower Snake and Columbia River. On the lower Snake River, the reservoir behind the Ice Harbor dam has reached temperatures above 68°F for 17 days. Below, we present the highest temperatures for each reservoir on the lower Snake and Columbia River.

A note on data information: The mean water temperature data from these reports comes from the USGS Current Conditions for Washington State and the 10-year average water temperature data comes from the Fish Passage Center. There is no available data for Lower Monumental 10-year average water temperature. Graphs and tables were assembled by SOS Staff.

III. WEEKLY HIGH TEMPERATURES: 7/26-8/1

Harmful water temperatures in the lower Snake River reservoirs: This week, all reservoirs peaked over the 68 degrees threshold. The reservoir behind the Ice Harbor Dam registered the highest temperature at 71.78°F on July 31st and August 1st. The Lower Monumental Dam registered the second highest temperature at 69.98°F on July 29th and July 31st.

On the lower Columbia River, all reservoirs peaked over the 68 degrees threshold. The reservoirs behind the John Day Dam registered the highest temperature at 72.68°F on July 31st.

 IV. Nez Perce Tribe’s “Snake Basin Chinook and Steelhead Quasi-Extinction Threshold” Analysis

Since time immemorial, the Nez Perce Tribe, also recognized as the Nimiipuu People, have been “connected to the lands and waters of modern-day Idaho, Washington, Oregon, and Montana long before the creation of the Nez Perce Reservation.”¹ As a sovereign nation within the United States, the Nez Perce Tribe retains the “inherent right to fish at usual and accustomed fishing stations, and hunt, gather, and graze livestock on open and unclaimed lands, all outside of the reservation boundary.”¹ However, due to “colonial encroachment, dam construction, and non-tribal fishing,” the numbers of traditional fishing sites for the Nez Perce Tribe and the number of fish have declined.² The Nez Perce Tribe’s Department of Fisheries Resources Management is a critical program that protects and enhances fishing rights reserved by the Tribe in its treaties with the United States.³ Notably, the Department of Fisheries Resources Management successfully brought back Snake River Fall Chinook from the brink of extinction, re-established coho salmon, once extirpated from the Snake River Basin, and has become one of the largest and most successful tribal fisheries programs in the United States.³

In May 2021, the Department of Fisheries Resources Management first presented their analysis called “Snake Basin Chinook and Steelhead Quasi-Extinction Threshold Alarm and Call to Action.” The 2022 update of this analysis, to include the 2021 returns, indicates that nearly half of the wild spring Chinook populations in the Snake River Basin have crossed a critical threshold known as the Quasi-Extinction Threshold (QET), signaling they are nearing extinction, and without intervention, many may not persist. In addition, the river’s steelhead populations also face alarming threats to their continued existence.

To understand what Quasi-Extinction Threshold (QET) means, the department outlined several definitions including: QET means 50 or fewer natural-origin spawners on the spawning grounds for 4 consecutive years. QET also signifies that adult salmon abundance in a population nearing absolute extinction, and the probability of recovery is low without substantial intervention.⁴

During the ‘Salmon Orca Summit’ in July 2021, Dave Johnson, Manager of the Nez Perce Tribe’s Department of Fisheries Resources Management, presented this analysis and stated, “Quasi-Extinction means, aside from biological terminology, you are running out of options. When you have fewer than 50 fish on spawning grounds, the genetic diversity is really limited. Your ability to pull these fish out of inbreeding depression and other stochastic-type risks is really limited. Any type of environmental hazard can cause havoc when you have fish populations that are so low. We are certainly running out of management options.”⁵

The analysis starts with a bar graph depicting the management goals and thresholds for the Snake River Chinook salmon and Snake River steelhead returns. The desired goal for a harvestable and healthy wild Chinook salmon population is 179,000.⁴ The minimum abundance for wild Chinook salmon is 29,250, and the critical threshold, also known as the Quasi-Extinction Threshold (QET), is 1,850 wild Chinook salmon.⁴ Desired steelhead numbers are 137,480, with a minimum abundance of 20,000, and a QET of 1,200.⁴

For the spring and summer Chinook populations, the graph above reflects the numbers of spawners in all 31 populations listed under the Endangered Species Act in the Snake River Basin. The department modeled the natural-origin spawner abundance estimates for Snake River Basin populations relative to the QET (dash line meaning 4 years below 50 fish) for the last 11-years (2011-2021).⁴ The dots on the graph signifies how many spawners were on the spawning grounds in that year.⁵ The red dots indicate that there were 50 or fewer spawners, but more importantly, the red title for that population indicates that there have been 50 or fewer natural origin spawners on the spawning grounds for at least four consecutive years.⁵ During the last four consecutive years, 13 (42%) of the 31 populations had more than 4 years of abundances below the QET.⁴

Similar to the analysis above, the summer steelhead populations graph reflects the numbers of spawners in all 16 populations, for which there was data, of the 25 listed under the Endangered Species Act in the Snake River Basin. The department modeled the natural-origin spawner abundance estimates for Snake River Basin populations relative to the QET for the last 11-years (2011-2021).⁴ During the last four consecutive years, 3 (19%) of the 16 populations had more than 4 years of abundances below the QET.⁴

Using the current trends, the department created a model to forecast future population levels for both Snake River spring and summer Chinook salmon and Snake River summer steelhead. The department found that the Chinook salmon populations are declining about 19% each year, and it is predicted that by 2026, 74% of spring and summer Chinook populations in the Snake River Basin are predicted to be at or below the Quasi-Extinction threshold in the Snake River Basin.⁵ The model clearly shows that 74% of the natural-origin spring and summer Chinook populations in the Snake River Basin will be closer to extinction within the next 5 years.⁴

The department also found that the summer steelhead populations are declining by approximately 15% each year and predictions show that by 2026, 6 (35%) summer steelhead populations are predicted to drop below 50 spawners within the next 5 years.⁴

The Snake and Columbia River Basin contains the best available habitat for salmon populations to recover to any significant level of abundance. However, with predictions pushing the populations below 50 spawners, the four lower Snake River dams are a major factor preventing salmon from reaching spawning grounds.

Current salmon and steelhead returns are higher than those of the past 5 years and these fish encountered suitable water temperatures in the lower Snake River reservoirs prior to mid-July. However, recent heat waves have caused temperatures to rise above 68°F. As stated by Jay Hesse, Director of Biological Services of the Nez Perce Tribe’s Department of Fisheries Resources Management, “The increase in Snake River basin natural-origin spring/summer returns occurring this year (2022) is welcomed and consistent with our expectations for improved survival under good ocean conditions and high spill hydro-operations. However, it is important to understand that while the 2022 return is an improvement over recent years, abundance remains precariously low and well below criteria for ESA-delisting - let alone our goals representing healthy and harvestable status.”

Restoring a freely flowing lower Snake River by removing its four federal dams is our only option to address high water temperatures and their impacts on wild salmon and steelhead as well as recovering salmon and steelhead from extinction. Dave Johnson stated in a recent presentation, "Breaching the dams improves survival [by speeding] the passage down to the ocean so fish travel in a river, not in a series of reservoirs. The fish evolutionarily are developed to make it down to the ocean in a certain amount of time. Well, we've extended that period of time to a month so they run out of reserves, they run out of their food by the time they reach the ocean."⁶

Wild salmon and steelhead returning to their spawning grounds in Idaho are met with high water temperatures of 68°F and above caused by a reservoir system. The dam’s reservoirs create large, stagnant pools that absorb heat from the sun, reaching lethal temperatures for salmon, which kill significant numbers of juvenile (smolts) and adult fish.

“The only way these fish are going to have a chance is if they can get back to the mountains,” stated Dave Johnson. “Otherwise, we lose them. We're losing them every year and we need to turn that around. We need to be able to breach the dams to have those fish get to where they're supposed to be.”⁶

The path forward is clear: we need a comprehensive solution to remove the lower Snake River dams and protect endangered salmon and orca from extinction, uphold our promises to Tribal Nations, create economic opportunities, and upgrade costly and aging energy, irrigation, and transportation infrastructure.

References:
1. Nez Perce Tribe History: Traditional Ways and Treaties
2. Nez Perce Tribe: Cultural Resource Program
3. Nez Perce Tribe: Fisheries Resources Management: DFRM-Management-Plan-2013-2028.pdf (nezperce.org)
4. Snake Basin Chinook and Steelhead Quasi-Extinction Threshold Alarm and Call to Action (2021)
5. Salmon Orca Summit 2021(July 8, 2021)
6. Declining Salmon: Salmon Orca Summit (May 20, 2022)

LINKS TO RECENT NEWS:

• Voice of America: Indigenous Communities Pushing for Dam Destruction to Boost Salmon (August 2, 2022)
• Adventure Journal: Western Wild Salmon Might Finally Get a Big Win They Desperately Need (August 1, 2022)

 Martha Campos is the Hot Water Report Coordinator with Save Our wild Salmon this summer while she resides on Kizh/Tongva ancestral lands in California. Martha holds a BA from the University of California, Davis in Native American Studies (and two minors: Environmental Policy, Analysis, and Planning and Climate Science and Policy) and is a queer, non-binary person of color with ancestral roots in Mexico.

I. INTRODUCTION

Welcome to Save Our wild Salmon’s Hot Water Report 2022.

During the summer, this weekly report will provide an update on real-time water temperatures in the lower Snake and Columbia River reservoirs via graphs and analyses, a summary on the highest weekly water temperatures at the forebay/reservoir of each dam, and the status of adult returns for different salmon and steelhead populations as they make their way back to their natal spawning grounds. We’ll hear first-hand from scientists, Tribal members, fishing guides, advocates, and other experts about the challenges facing the Columbia and Snake rivers - and our opportunities to improve and restore them - in order to recover healthy, resilient fish populations and the benefits they deliver to the Northwest’s culture, economy, and ecology.

The once-abundant anadromous fish populations of the Columbia-Snake River Basin are struggling to survive today in large part due to multiple harms caused by the system of federal dams and reservoirs. The federal hydro-system creates conditions that harm and kill both juvenile and adult fish, including by elevating water temperatures in large, stagnant reservoirs in the summer months. These cold-water fish begin to suffer harmful effects when water temperatures exceed 68° Fahrenheit. The longer and the higher these temperatures rise above 68°F, the greater the harm, including: migration disruption, increased metabolism, increased susceptibility to disease, reduced fecundity or reproductive potential (by reducing egg viability), suffocation (warm water carries less oxygen), and in the worst case - death.

Today, these harmful hot waterepisodes above 68°F in the Columbia and Snake Rivers are increasing in duration, frequency, and intensity. Our changing climate is making a bad situation for the Northwest’s iconic fish worse. Our region and nation must take urgent action to re-establish cool water temperatures - or we will lose these species forever. Restoring a freely flowing lower Snake River by removing its four federal dams is likely our only option to address high water temperatures in this 140-mile stretch of river running through southeast Washington State. Restoring the Snake River is one essential element of what must be a larger regional strategy to protect and rebuild healthy, abundant salmon and steelhead populations in order to benefit other fish and wildlife populations, including critically endangered Southern Resident orcas, to uphold our nation’s promises to Native American tribes, and to ensure prosperous communities across the Northwest.

The Hot Water Report 2022 is a joint project of the Save Our wild Salmon Coalition, Columbia Riverkeeper, American Rivers, Endangered Species Coalition, Environment Washington, Idaho Conservation League, Idaho Rivers United, Idaho Wildlife Federation, National Resource Defense Council, National Wildlife Federation, Nimiipuu Protecting the Environment, Northwest Sportfishing Industry Association, Sierra Club, Snake River Waterkeeper, Spokane Riverkeeper, Wild Orca, and Wild Steelhead Coalition.

II. READING THE DATA - Lower Snake and Columbia River Temperatures

The daily mean temperature at the four reservoir forebays (immediately upstream from the dam) in the lower Snake River (above) and the lower Columbia River (below) for 2022 is represented with solid lines and their 10-year average (2012 - 2022) temperatures with dashed lines of the same color. The dotted line across the graph represents the 68°F “harm threshold” for adult and juvenile fish. Salmon and steelhead begin to suffer harmful effects when water temperatures exceed 68° Fahrenheit. The longer temperatures remain above 68°F and the higher the temperatures rise above 68°F, the more severe the potential effects, including: increased metabolism, increased susceptibility to disease, reduced fecundity or reproductive potential, and/or death.

Since April, temperatures in the lower Snake River and the lower Columbia River reservoirs have steadily moved upward. During April and May, trends tracked closely with the 10-year average. In June, however, water temperatures have dropped considerably below this average. This was good news for cold-water species like salmon and steelhead, though we expect these temperatures will rise considerably in these reservoirs as the summer progresses. This week, in fact, temperatures rapidly increased in the lower Snake River. The reservoir behind the Little Goose Dam had the highest mean temperature of 66.20°F and the Ice Harbor Dam’s reservoir had the second highest mean temperature of 66.02°F.

A note on data information: The mean water temperature data from these reports comes from the USGS Current Conditions for Washington State and the 10-year average water temperature data comes from the Fish Passage Center. There is no available data for Lower Monumental 10-year average water temperature. Graphs and tables were assembled by SOS Staff.

 III. WEEKLY HIGH TEMPERATURES: 7/5-7/11

On the lower Snake River this week, the reservoir behind the Little Goose Dam registered the highest temperature at 67.10°F, followed closely by the Lower Monumental and Ice Harbor reservoir at 66.38°F.

On the lower Columbia River, the reservoirs behind the John Day Dam registered the highest temperature at 66.02°F.

IV. A Look at Snake River Wild Salmon & Steelhead Adult Returns

The Snake River's anadromous fish populations have been on a steady downward trajectory across the last several decades. These salmon and steelhead face multiple obstacles, including dangerously hot water in the summer months in the Snake River reservoirs. Below, we present background information on and current status of native fish returns, including (1) wild/natural sockeye, (2) wild Snake River Spring/Summer Chinook, and (3) wild steelhead. We will also look at how the historical and current numbers of returning adults compare to established recovery goals - the adult returns deemed necessary to recover these populations and remove them from the Endangered Species Act list.

In summary - since the four lower Snake River dams were built, over 60 years ago, Snake River salmon and steelhead populations have been in a steady decline. Each year, these fish return (far) below the recovery goals necessary to remove them from the Endangered Species Act list. Without immediate and meaningful conservation actions, scientists predict we will lose these populations forever.

A. What Are Wild Salmon and Steelhead Returns?

The size and condition of a given population of salmon or steelhead is typically measured by the number of adult fish that return from the ocean to their upriver spawning grounds each year. The most straightforward method to measure the size of a salmon run is to count the fish as they swim upstream.

Snake River salmon and steelhead runs are counted at Lower Granite Dam, the last impediment on the river before the fish enter thousands of miles of tributary spawning and rearing habitat in central Idaho and eastern Oregon, and southeast Washington State. Returning salmon have been counted at the farthest upstream dam on the lower Snake River since Ice Harbor Dam was first completed in 1962. This dataset of 60+ years, coupled with informed estimates of run sizes before the dams were constructed, provides valuable insight into the precipitous declines wild salmon and steelhead have experienced in the last 4-5 decades.

B. Historical Context

The health of these populations has plummeted over time from historic levels that were once in the hundreds of thousands or millions, depending on the particular population.

Enthusiasm about an uptick in returns in a given year is a symptom of the “shifting baseline syndrome,” where the perception of what constitutes a healthy population is based only on recent reference points. These benchmarks are very low already as a result of long-term population declines. The result is that our collective perception of what constitutes a healthy salmon run is continually shifting downward. Put simply, the Columbia and Snake River Basin historically (before the dams) produced over 10 to 16 million returning wild adult salmon and steelhead.¹ The Snake River Basin by itself produced nearly half of all the spring chinook that returned annually to the much-larger Columbia Basin. Notably, the once-numerous and fat-rich spring chinook of the Columbia and Snake rivers have been very important to the health of Southern Resident orcas who have historically relied upon them during the winter months when few other salmon are available in the coastal waters of the West Coast.

C. Recovery Goals: Informed By the Past, Potential for the Future

High-end recovery goals for wild Snake River salmon and steelhead have been set to reflect the healthy runs that returned to Idaho in the 1950s – before the dams were constructed. The goals represent self-sustaining, harvestable populations that currently available, high-quality habitat in the Snake River Basin could support. Restoring abundant populations will allow salmon to once again function as keystone species, feeding countless animals, forests, and plants, and supporting Northwesterners' cultures and economies. Restoring the lower Snake River through dam removal is our most significant river/salmon restoration opportunity anywhere in the nation today. Scientists predict it can regularly produce more than a million adult salmon and steelhead entering the mouth of the Columbia River in the spring and summer months.

D. Current Status of Snake River Returns as of July 1, 2022

(i) Snake River Sockeye

• Endangered Species Act Status: Endangered (listed in 1991)
• Historical Annual Return: Over 100,000+/yr to central Idaho’s high mountain lakes¹
• Recovery Goal: 9,000 wild adults per year to the Stanley Basin
• 2021 Returns²:4 wild/natural-origin sockeye returned to the Stanley Basin

Historic runs to Idaho’s high mountain lakes used to be over 100,000+ sockeye per year but have also severely declined over the years.¹ In the early 1990s, there were no adult returns for sockeye salmon due to harmful conditions the lower Snake River dams produced, and as a result, sockeye were first listed as an endangered species under the Endangered Species Act in 1991.³

The 10-year average for sockeye returning to the Stanley Basin in central Idaho is just 80 fish and a recovery goal of 9,000 wild sockeye per year. Last year, due to hot conditions, most fish did not have a chance to return to spawning grounds in central Idaho's mountain lakes. Idaho Fish and Game trapped the sockeye that arrived at Lower Granite Dam and hauled them by truck to an Idaho fish hatchery as a precautionary conservation measure.

Hot water is jeopardizing the existence of this already very fragile salmon and steelhead run. Last summer, video footage and images showed sockeye with large, open lesions and fungus caused by hot water conditions from the lower Snake and lower Columbia River reservoirs. Only 4 wild adult sockeye salmon survived to swim into their spawning grounds in the Stanley Basin in central Idaho after struggling past eight dams and warm and stagnant reservoirs downstream.

(ii) Snake River Spring/Summer Chinook:

• Endangered Species Act Status: Threatened (listed in 1992)
• Historical Annual Return: Over 2 million¹
• Recovery Goal: Escapement of 127,000 wild adults per year
• 2021 Returns²: 6,563

Spring/summer chinook were once the Pacific Northwest’s most widely distributed and abundant salmon, numbering in the millions. The Salmon River alone produced 39 percent of the spring chinook and 45 percent of the summer chinook in the entire Columbia River Basin.¹ Currently, an estimated 14,213 wild spring/summer Chinook have returned from the ocean to their upriver spawning grounds in Idaho.

In June, water temperatures dropped considerably below the 10-year average for the month (see Lower Snake and Columbia River Temperatures graphs above). This was good news for cold-water species like salmon and steelhead, though these temperatures are rising in these reservoirs as the summer progresses. Despite this year's increase of adult return wild spring/summer Chinook, we remain from recovery and the population remains in long-term decline.

(iii) Snake River Steelhead

• Endangered Species Act Status: Threatened (listed in 1997)
• Historical Annual Return: Over 1 million¹
• Recovery Goal: Escapement of 104,500 wild adults per year
• 2021 Returns²: 15,478

Historic runs of steelhead to the Snake River Basin were estimated to be over one million fish annually.¹ The Snake River and its tributaries produced 55 percent of summer steelhead in the entire Columbia River basin.¹ During the summer of 2021, steelhead saw the lowest returns in history, forcing emergency fishing closures in Washington and Oregon.

An estimated 15,478 wild steelhead have returned from the ocean to their upriver spawning grounds in Idaho in 2021,which is well below the 10-year average of 22,735 and the recovery goal of 104,500 wild steelhead adults per year. Given the current returns for wild Snake River chinook, steelhead, and sockeye, these fish are much closer to extinction than recovery.

E. Hot Water Impacts

The hot, dry conditions during each summer are forecast to become increasingly the norm due to climate change. Periods of prolonged hot water in the Snake River reservoirs are lethal to these coldwater species returning to the Snake River.

The four federal dams and their reservoirs on the lower Snake River in southeast Washington State continue to be the main obstacle to recovery. The rising temperatures caused by these stagnant reservoirs and reductions in snowpack in recent decades due to climate change are contributing to lower survival and reproductive success for already endangered salmon and steelhead. As a result, wild Snake River Chinook, steelhead, and sockeye are much closer to extinction than established recovery goals. Despite spending over 26 billion dollars on recovery projects, long-term trends for these populations have left these species at grave risk of extinction.

Restoring this historic salmon river is essential for protecting these fish from extinction and rebuilding the many benefits they provide for the people of the Northwest and our nation.

References:
1. The Salmon Community’s View: The status of wild salmon and steelhead populations in the Columbia and Snake River Basin (2016)
2. Idaho Rivers United: Snake River Salmon Returns (July 1, 2022)
3. Idaho Fish and Game: Sockeye Salmon (2005)

LINKS TO RECENT NEWS:

• The Herald Letters to the Editor: Waiting could force bad choice on dams, salmon(July 3, 2022)
• Seattle Times Opinion: The future of the Lower Snake River Dams: Do the right thing for salmon, tribes and communities (July 8, 2022)
• Yakima Herald Opinion: Breaching dams is key to saving salmon, steelhead and orcas | Opinion (July 10, 2022)
• Seattle Times: White House weighs in on lower Snake River dam breaching in unusual power play (July 12, 2022)
• The White House: Federal Agencies Announce Two New Analyses to Help Inform Restoration of Columbia River Basin Salmon and Long-Term Energy Planning in the Pacific Northwest (July 12, 2022)

 Martha Campos is the Hot Water Report Coordinator with Save Our wild Salmon this summer while she resides on Kizh/Tongva ancestral lands in California. Martha holds a BA from the University of California, Davis in Native American Studies (and two minors: Environmental Policy, Analysis, and Planning and Climate Science and Policy) and is a queer, non-binary person of color with ancestral roots in Mexico.

I. INTRODUCTION

Welcome to Save Our wild Salmon’s Hot Water Report 2022.

During the summer, this weekly report will provide an update on real-time water temperatures in the lower Snake and Columbia River reservoirs via graphs and analyses, a summary on the highest weekly water temperatures at the forebay/reservoir of each dam, and the status of adult returns for different salmon and steelhead populations as they make their way back to their natal spawning grounds. We’ll hear first-hand from scientists, Tribal members, fishing guides, advocates, and other experts about the challenges facing the Columbia and Snake rivers - and our opportunities to improve and restore them - in order to recover healthy, resilient fish populations and the benefits they deliver to the Northwest’s culture, economy, and ecology.

The once-abundant anadromous fish populations of the Columbia-Snake River Basin are struggling to survive today in large part due to multiple harms caused by the system of federal dams and reservoirs. The federal hydro-system creates conditions that harm and kill both juvenile and adult fish, including by elevating water temperatures in large, stagnant reservoirs in the summer months. These cold-water fish begin to suffer harmful effects when water temperatures exceed 68° Fahrenheit. The longer and the higher these temperatures rise above 68°F, the greater the harm, including: migration disruption, increased metabolism, increased susceptibility to disease, reduced fecundity or reproductive potential (by reducing egg viability), suffocation (warm water carries less oxygen), and in the worst case - death.

Today, these harmful hot waterepisodes above 68°F in the Columbia and Snake Rivers are increasing in duration, frequency, and intensity. Our changing climate is making a bad situation for the Northwest’s iconic fish worse. Our region and nation must take urgent action to re-establish cool water temperatures - or we will lose these species forever. Restoring a freely flowing lower Snake River by removing its four federal dams is likely our only option to address high water temperatures in this 140-mile stretch of river running through southeast Washington State. Restoring the Snake River is one essential element of what must be a larger regional strategy to protect and rebuild healthy, abundant salmon and steelhead populations in order to benefit other fish and wildlife populations, including critically endangered Southern Resident orcas, to uphold our nation’s promises to Native American tribes, and to ensure prosperous communities across the Northwest.

The Hot Water Report 2022 is a joint project of the Save Our wild Salmon Coalition, Columbia Riverkeeper, American Rivers, Endangered Species Coalition, Environment Washington, Idaho Conservation League, Idaho Rivers United, Idaho Wildlife Federation, National Resource Defense Council, National Wildlife Federation, Nimiipuu Protecting the Environment, Northwest Sportfishing Industry Association, Sierra Club, Snake River Waterkeeper, Spokane Riverkeeper, Wild Orca, and Wild Steelhead Coalition.

II. READING THE DATA - Lower Snake and Columbia River Temperatures

Introduction: The daily mean temperature at the four reservoir forebays (immediately upstream from the dam) in the lower Snake River (above) and the lower Columbia River (below) for 2022 is represented with solid lines and their 10-year average (2012 - 2022) temperatures with dashed lines of the same color. The dotted line across the graph represents the 68°F “harm threshold” for adult and juvenile fish. Salmon and steelhead begin to suffer harmful effects when water temperatures exceed 68° Fahrenheit. The longer temperatures remain above 68°F and the higher the temperatures rise above 68°F, the more severe the potential effects, including: increased metabolism, increased susceptibility to disease, reduced fecundity or reproductive potential, and/or death (see Issue 1 for more detailed information).

Discussion: Since April, temperatures in the lower Snake River and the lower Columbia River reservoirs have steadily moved upward. During April and May, trends have tracked closely with the 10-year average. In June, however, water temperatures dropped considerably below this average. This was good for cold-water species like salmon and steelhead, but now, temperatures have reached the 68°F “harm threshold” in the reservoirs on the lower Snake River. Below, we present the highest temperatures for each reservoirs on the lower Snake River

A note on data information: The mean water temperature data from these reports comes from the USGS Current Conditions for Washington State and the 10-year average water temperature data comes from the Fish Passage Center. There is no available data for Lower Monumental 10-year average water temperature. Graphs and tables were assembled by SOS Staff.

III. WEEKLY HIGH TEMPERATURES: 7/12-7/18

Harmful water temperatures in the lower Snake River reservoirs: This week, on the lower Snake River, the Little Goose, Lower Monumental, and Ice Harbor Dams have peaked over the threshold (68 degrees). The reservoir behind the Little Goose Dam registered the highest temperature at 68.72°F on July 15th and the Ice Harbor reservoir registered the second highest temperature at 68.54°F on July 18th.

On the lower Columbia River, the reservoirs behind the Bonneville Dam registered the highest temperature at 67.1°F.

IV. COLUMBIA RIVERKEEPER REPORT (2017): Removing dams will reduce lower Snake River water temperatures and deliver critical survival benefits to endangered salmon and steelhead

In 2015, high water temperatures driven by hot weather and a low snowpack killed more than 250,000 salmon in the Columbia and Snake rivers. This incident of mass mortality inspired SOS member organization Columbia Riverkeeper to produce a report—Columbia Riverkeeper White Paper: Computer modeling shows that Lower Snake River dams caused dangerously hot water for salmon in 2015—evaluating what the water temperatures of the lower Snake would have been during the summer of 2015 if its four federal dams did not exist.

Using a U.S. Environmental Protection Agency (EPA) water temperature model, Columbia Riverkeeper found that each of the four reservoirs behind the dams increased the river temperature by about 2°F. The reservoirs create large, stagnant pools that steadily absorb heat from the sun. When warm water from one reservoir moves downstream to the next pool, the already-warmed water is stopped again by the next dam and continues to heat up. The model indicates clearly that this effect would be absent from the free-flowing lower Snake River.

Since Columbia Riverkeeper published its study in 2017, federal science agencies have released more information corroborating its findings. First, the U.S. Army Corps of Engineers used EPA’s model, as well as another water temperature model, to recreate Columbia Riverkeeper’s study—and got similar results.¹ Second, the EPA released a study showing that, in warm years, water flowing into the lower Snake River is cool enough for fish, but water flowing out of the lower Snake River is too hot, and the dams cause much of this heat pollution.²

A free-flowing lower Snake River would not absorb the same amount of solar radiation. Considerably cooler waters deliver big benefits to migrating juvenile and adult salmon and steelhead populations—leading to increased survival and reproductive success. A free-flowing lower Snake River would also extend the benefit of cold water released from Dworshak reservoir upstream on the Clearwater River in the hot summer months.

Dworshak Dam’s large reservoir is used today to deliver cold water into the Clearwater River, just upstream from its confluence with the Snake River at Lewiston, Idaho. As long as these four dams remain in place, however, the benefits of Dworshak’s cold flows into the lower Snake River are highly limited and serve only as a local, short-term solution to cooling water temperatures to the Lower Granite Dam’s reservoir.

By restoring this 140-mile stretch of the lower Snake River through dam removal, EPA models used in Columbia Riverkeeper’s report show that, while temperatures in a freely flowing river may spike above 68 degrees periodically, they will quickly return to the cool temperatures that salmon and steelhead need to survive and migrate. With a restored LSR, cold summer flows from behind Dworshak Dam would further help keep temperatures healthy for fish from Lewiston (ID) all the way downstream to where the Snake River joins the Columbia River in south-central Washington State near the Tri-Cities.

In summarizing findings of the study, Miles Johnson, senior attorney at Columbia Riverkeeper, notes that "removing the four lower Snake River dams would keep the river cooler and help salmon reach their spawning areas. This is critical for healthy salmon and a healthy river—especially as the changing climate tightens its grip on our waters in the Northwest. It's time for bold action to protect the Northwest's fishing traditions, orcas, and salmon. It’s time to restore the lower Snake River."

The federal government’s latest Columbia-Snake salmon plan—developed during the Trump Administration by Bonneville Power Administration, and Army Corps of Engineers—fails to contain any effective strategy to maintain cool, salmon-friendly water temperatures in these reservoirs during the summer months. The Trump Plan has been challenged in court by the Nez Perce Tribe, the state of Oregon, and more than a dozen conservation and fishing organizations (and members of the Save Our wild Salmon Coalition). Notably, this litigation was paused last October to allow the parties time to negotiate a solution to restore the fish and end the litigation. This pause will expire on July 31st, unless the parties agree to an extension, subject to court approval.

Big news broke last week when the Biden Administration announced two new reports to help inform the restoration of Columbia River Basin salmon and long-term energy planning in the Pacific Northwest. 'Rebuilding Interior Columbia Basin Salmon and Steelhead' from NOAA confirms the actions needed to restore salmon and steelhead in the Columbia Basin, including lower Snake River dam removal. In the press release announcing these reports, CEQ Chair, Brenda Mallory said, “Business as usual will not restore the health and abundance of Pacific Northwest salmon. We need a durable, inclusive, and regionally-crafted long-term strategy for the management of the Columbia River Basin." The second report from USDOE and BPA focuses on energy replacement. This analysis confirms what several other studies show: we can develop a portfolio of clean energy resources to feasibly and affordably replace the dams’ energy services. Studies and analyses continue to accumulate and reinforce each other re: the urgency and opportunity to restore salmon and steelhead in the Columbia Basin - including the removal of the lower Snake River dams and launching a comprehensive energy replacement planning process.

References:
1. U.S. Army Corps of Engineers, Final Environmental Impact Statement for Columbia River System Operations, Appendix D, p. A-1-28 (2020).
2. EPA, Columbia and Lower Snake River Temperature TMDL, pp. 47–50 (2020).

Watch this National Wildlife Federation Outdoors video for quick primer on hot water and wild salmon

Finally, for a clear, compelling summary of how hot water harms and kills salmon and steelhead, view this 2-minute video produced by National Wildlife Federation Outdoors.

LINKS TO RECENT NEWS:

• NOAA Fisheries Report: Rebuilding Interior Columbia Basin Salmon and Steelhead (July 11, 2022)
• White House CEQ Press Release: Federal Agencies Announce Two New Analyses to Help Inform Restoration of Columbia River Basin Salmon and Long-Term Energy Planning in the Pacific Northwest(July 12, 2022)
• Seattle Times: White House weighs in on Lower Snake River dam breaching in unusual power play (July 12, 2022)
• E&E News: NOAA: Breaching Snake River dams ‘essential’ to save salmon (July 12, 2022)
• DCJ Oregon: White House: To help salmon, dams may need to be removed (July 12, 2022)
• NWNews: Federal report recommends breaching Lower Snake River dams to restore salmon (July 12, 2022)
• The Columbian: In Our View: Solutions, not more studies, to save salmon (July 18, 2022)
• Lewiston Tribune Editorial: Where once there were carrots, now there are sticks (July 17, 2022)

 Martha Campos is the Hot Water Report Coordinator with Save Our wild Salmon this summer while she resides on Kizh/Tongva ancestral lands in California. Martha holds a BA from the University of California, Davis in Native American Studies (and two minors: Environmental Policy, Analysis, and Planning and Climate Science and Policy) and is a queer, non-binary person of color with ancestral roots in Mexico.

I. INTRODUCTION

Welcome to Save Our wild Salmon’s Hot Water Report 2022.

During the summer, this weekly report will provide an update on real-time water temperatures in the lower Snake and Columbia River reservoirs via graphs and analyses, a summary on the highest weekly water temperatures at the forebay/reservoir of each dam, and the status of adult returns for different salmon and steelhead populations as they make their way back to their natal spawning grounds. We’ll hear first-hand from scientists, Tribal members, fishing guides, advocates, and other experts about the challenges facing the Columbia and Snake rivers - and our opportunities to improve and restore them - in order to recover healthy, resilient fish populations and the benefits they deliver to the Northwest’s culture, economy, and ecology.

The once-abundant anadromous fish populations of the Columbia-Snake River Basin are struggling to survive today in large part due to multiple harms caused by the system of federal dams and reservoirs. The federal hydro-system creates conditions that harm and kill both juvenile and adult fish, including by elevating water temperatures in large, stagnant reservoirs in the summer months. These cold-water fish begin to suffer harmful effects when water temperatures exceed 68° Fahrenheit. The longer and the higher these temperatures rise above 68°F, the greater the harm, including: migration disruption, increased metabolism, increased susceptibility to disease, reduced fecundity or reproductive potential (by reducing egg viability), suffocation (warm water carries less oxygen), and in the worst case - death.

Today, these harmful hot waterepisodes above 68°F in the Columbia and Snake Rivers are increasing in duration, frequency, and intensity. Our changing climate is making a bad situation for the Northwest’s iconic fish worse. Our region and nation must take urgent action to re-establish cool water temperatures - or we will lose these species forever. Restoring a freely flowing lower Snake River by removing its four federal dams is likely our only option to address high water temperatures in this 140-mile stretch of river running through southeast Washington State. Restoring the Snake River is one essential element of what must be a larger regional strategy to protect and rebuild healthy, abundant salmon and steelhead populations in order to benefit other fish and wildlife populations, including critically endangered Southern Resident orcas, to uphold our nation’s promises to Native American tribes, and to ensure prosperous communities across the Northwest.

The Hot Water Report 2022 is a joint project of the Save Our wild Salmon Coalition, Columbia Riverkeeper, American Rivers, Endangered Species Coalition, Environment Washington, Idaho Conservation League, Idaho Rivers United, Idaho Wildlife Federation, National Resource Defense Council, National Wildlife Federation, Nimiipuu Protecting the Environment, Northwest Sportfishing Industry Association, Sierra Club, Snake River Waterkeeper, Spokane Riverkeeper, Wild Orca, and Wild Steelhead Coalition.

II. READING THE DATA - Lower Snake and Columbia River Temperatures

Introduction: The daily mean temperature at the four reservoir forebays (immediately upstream from the dam) in the lower Snake River (above) and the lower Columbia River (below) for 2022 is represented with solid lines and their 10-year average (2012 - 2022) temperatures with dashed lines of the same color. The dotted line across the graph represents the 68°F “harm threshold” for adult and juvenile fish. Salmon and steelhead begin to suffer harmful effects when water temperatures exceed 68° Fahrenheit. The longer temperatures remain above 68°F and the higher the temperatures rise above 68°F, the more severe the potential effects, including: increased metabolism, increased susceptibility to disease, reduced fecundity or reproductive potential, and/or death (see Issue 1 for more detailed information).

Discussion: Since April, temperatures in the lower Snake River and the lower Columbia River reservoirs have steadily moved upward. During April and May, trends have tracked closely with the 10-year average. In June, however, water temperatures dropped considerably below this average. This was good for cold-water species like salmon and steelhead, but now, temperatures have reached the 68°F “harm threshold” in the reservoirs on the lower Snake and Columbia River. Below, we present the highest temperatures for each reservoir on the lower Snake River.

A note on data information: The mean water temperature data from these reports comes from the USGS Current Conditions for Washington State and the 10-year average water temperature data comes from the Fish Passage Center. There is no available data for Lower Monumental 10-year average water temperature. Graphs and tables were assembled by SOS Staff.

III. WEEKLY HIGH TEMPERATURES: 7/19-7/25

Harmful water temperatures in the lower Snake River reservoirs: This week, on the lower Snake River, the Little Goose, Lower Monumental, and Ice Harbor Dams have peaked over the threshold (68 degrees). The reservoir behind the Ice Harbor reservoir registered the highest temperature at 69.98°F on July 23rd and July 25th and the Little Goose Dam registered the second highest temperature at 69.80°F on July 25th.

On the lower Columbia River, all reservoirs peaked over the 68 degrees threshold. The reservoirs behind the Bonneville and the John Day Dam registered the highest temperature at 69.26°F on July 25th.

 IV. SALMON OR CLEAN ENERGY: DO WE HAVE TO CHOOSE?

Defenders of the embattled lower Snake River dams (LSRD) claim that we can’t restore a free-flowing lower Snake River to recover abundant salmon and steelhead runs, while providing reliable power and meeting our clean energy goals.

Is this true? Can we restore salmon and still have reliable, climate-friendly electricity, or do we have to choose one or the other, but not both?

Let’s start by defining what the dams do (and don’t) contribute to meeting Northwest electricity demand. The four lower Snake dams have a nameplate capacity of 3,033 megawatts (MW), ostensibly enough to serve three cities the size of Seattle. But on an annual basis, they actually generate far less than that: just 888 average megawatts (aMW) – a 29.7% capacity factor (depending on siting, NW wind projects have a 35-50% capacity factor, NW solar about 25%). And the dams’ production of “firm power” – energy that can be generated even in years of exceptionally low stream flows -- is substantially less: just 438 aMW.

Why so low? Because the lower Snake dams are “run-of-the-river” dams, as they do not store water for power production (or flood control, for that matter). The LSRD produce the most power in the spring snowmelt season and much less in other seasons. In addition, climate change is creating challenges for the existing hydropower system. Warming temperatures mean more precipitation in the Northwest falls as rain rather than snow, which causes less, and earlier snowmelt that is needed to power the LSRD. Droughts are expected to increase in both frequency and magnitude which results in lower river flows causing less water to generate power from the dams, especially in summer.

Unfortunately, massive droughts, and warmer temperatures will become more common as climate change continues to advance and will continue to threaten both our fish and the reliability of our region’s power supply.

However, do we have enough clean energy available to replace the four lower Snake River dams’ energy services? Both computer modeling results and real-world evidence say that the answer is yes.

In 2018 Energy Strategies LLC, a respected mainstream energy consulting firm analyzed options for replacing the energy services of the lower Snake dams. Their study found that:

It is possible for a set of clean energy resources to replace the most important power attributes that the four LSR Dams are forecasted to contribute to the Northwest region. The level of wind, solar, energy efficiency, demand response, and battery storage required to achieve sufficient replacement, as defined by this study, is readily available in the region.¹

They concluded that the cost would be little more than $1.25 on an average monthly residential power bill, and system reliability would be maintained or increased.

In 2022, Energy Strategies did an updated analysis of the issue that reaffirmed the 2018 findings but added that:

The study suggests that replacement portfolios will generate power at times when the region needs it the most, resulting in $69M - $131M million per year of energy value above and beyond what the LSR dams provide for the same time period. This result is heavily driven by the LSR dams generating most of their annual energy output during the spring runoff season when power prices are low and the region exports its excess energy.²

The resources in the Energy Strategies replacement portfolios are all “market-ready”, available in the 2024-2028 time frame. The resources selected were chosen from the Bonneville Power Administration’s “transmission queue” – specific projects with sponsors, sites and technology who have notified Bonneville that they will need transmission services when their project is acquired by a regional utility. The replacement portfolios selected only 12% of the resources in the queue.

Perhaps even more compelling evidence comes from the results of recent NW utility requests for proposals (RFP) seeking new energy and capacity resources.

In 2020 PacifiCorp issued an RFP for about 4,300 MW of energy and capacity resources
for delivery by 2024. Bids into the RFP totaled over 36,000 MW. PacifiCorp then selected a mix
of wind, solar and batteries totaling 4,000 MW.

In 2021 Puget Sound Energy issued an RFP for about 3,200 MW of energy and capacity to
be available to the utility in 2025. Bids into the RFP for wind, solar and batteries totaled about
18,000 MW, Puget will make a final selection later this year.

Each of these RFPs sought more energy and capacity than the combined capability of the four lower Snake dams and were each oversubscribed by 5-8 times. There are energy resources – today – that are far more capable to replace the energy services of the lower Snake dams.

Studies and real-world evidence all point towards adding a balanced mix of renewable resources, energy storage, and customer-side resources to replace the power from the lower Snake River dams. We have a unique opportunity to diversify our energy sources, invest in clean energy solutions like solar and wind power, increase energy efficiency and energy storage, and provide customer-side resources as well as develop more resilient solutions to protect and recover salmon and steelhead populations.

References:
1. NW Energy Coalition: The Lower Snake River Dams Power Replacement Study (April, 2018)
2. NW Energy Coalition: Smart Planning Will Drive Replacing the Power from Lower Snake River Dams (February, 2022)

LINKS TO RECENT NEWS:

• Everett Herald Op-Ed: Comment: Our grid can save salmon and a green energy future (July 24, 2022)
• Post Alley: Glimmers: Some Hope for a Solution for Northwest Dams? (July 27, 2022)
• King 5: Advocates show support for removal of Snake River dams (July 14, 2022)

 Martha Campos is the Hot Water Report Coordinator with Save Our wild Salmon this summer while she resides on Kizh/Tongva ancestral lands in California. Martha holds a BA from the University of California, Davis in Native American Studies (and two minors: Environmental Policy, Analysis, and Planning and Climate Science and Policy) and is a queer, non-binary person of color with ancestral roots in Mexico.

I. INTRODUCTION

Welcome to Save Our wild Salmon’s Hot Water Report 2022.

During the summer, this weekly report will provide an update on real-time water temperatures in the lower Snake and Columbia River reservoirs via graphs and analyses, a summary on the highest weekly water temperatures at the forebay/reservoir of each dam, and the status of adult returns for different salmon and steelhead populations as they make their way back to their natal spawning grounds. We’ll hear first-hand from scientists, Tribal members, fishing guides, advocates, and other experts about challenges facing the Columbia and Snake Rivers - and our opportunities to improve and restore them - in order to recover healthy, resilient fish populations and the benefits they deliver to the Northwest’s culture, economy, and ecology.

The once-abundant anadromous fish populations of the Columbia-Snake River Basin are struggling to survive today in large part due to multiple harms caused by the system of federal dams and reservoirs. The federal hydro-system creates conditions that harm and kill both juvenile and adult fish, including by elevating water temperatures in large, stagnant reservoirs in the summer months. These cold-water fish begin to suffer harmful effects when water temperatures exceed 68° Fahrenheit. The longer and the higher these temperatures rise above 68°F, the greater the harm, including: migration disruption, increased metabolism, increased susceptibility to disease, reduced fecundity or reproductive potential (by reducing egg viability), suffocation (warm water carries less oxygen), and in the worst case - death.

These harmful hot waterepisodes above 68°F in the Columbia and Snake Rivers are increasing in duration, frequency, and intensity. Our changing climate is making a bad situation for the Northwest’s iconic fish worse. Our region and nation must take urgent action to maintain cool water temperatures - or we will lose these species forever. Restoring a freely flowing lower Snake River by removing its four federal dams is likely our only option to address high water temperatures in this 140-mile stretch of river running through southeast Washington State. Restoring the Snake River is one essential element of what must be a larger regional strategy to protect and rebuild healthy, abundant salmon and steelhead populations in order to benefit other fish and wildlife populations, including critically endangered Southern Resident orcas, to uphold our nation’s promises to Native American tribes, and to ensure prosperous communities across the Northwest.

The Hot Water Report is a joint project of the Save Our wild Salmon Coalition, Columbia Riverkeeper, American Rivers, Endangered Species Coalition, Environment Washington, Idaho Conservation League, Idaho Rivers United, Idaho Wildlife Federation, National Resource Defense Council, National Wildlife Federation, Nimiipuu Protecting the Environment, Northwest Sportfishing Industry Association, Sierra Club, Snake River Waterkeeper, and Wild Steelhead Coalition.

II. READING THE DATA - Lower Snake and Columbia River Temperatures

The daily mean temperature at the four reservoir forebays (immediately upstream from the dam) in the lower Snake River (above) and the lower Columbia River (below) for 2022 is represented with solid lines and their 10-year average (2012 - 2022) temperatures with dashed lines of the same color. The dotted line across the graph represents the 68°F “harm threshold” for adult and juvenile fish. Salmon and steelhead begin to suffer harmful effects when water temperatures exceed 68° Fahrenheit. The longer temperatures remain above 68°F and the higher the temperatures rise above 68°F, the more severe the potential effects, including: increased metabolism, increased susceptibility to disease, reduced fecundity or reproductive potential, and/or death.

Since April, temperatures in the lower Snake River and the lower Columbia River reservoirs have steadily moved upward. During April and May, trends have tracked closely with the 10-year average. In June, however, water temperatures have dropped considerably below this average. This is good news for cold-water species like salmon and steelhead, though we expect these temperatures will rise considerably in these reservoirs as the summer progresses. The reservoir behind the Little Goose Dam had the highest mean temperature of 55.76°F and Ice Harbor Dam’s reservoir had the second highest mean temperature of 55.22°F. A note on data information: The mean water temperature data from these reports comes from the USGS Current Conditions for Washington State and the 10-year average water temperature data comes from the Fish Passage Center. There is no available data for Lower Monumental 10-year average water temperature. Graphs and tables were assembled by SOS Staff.

III. WEEKLY HIGH TEMPERATURES: 6/13-6/20

On the lower Snake River this week, the reservoir behind the Little Goose Dam registered the highest temperature at 56.66°F, followed closely by Lower Granite and Lower Monumental reservoirs with 56.66°F.

On the lower Columbia River, the reservoir behind the Bonneville Dam registered the highest temperature at 57.92°F. The second highest temperatures came from the reservoirs behind The Dalles Dam and the John Day Dam with a temperature of 57.56°F.

IV. How the Snake and Columbia river reservoirs harm endangered salmon and steelhead populations.

Historically, abundant Snake and Columbia River salmon and steelhead delivered vast cultural, economic, nutritional, and ecological benefits to the people and fish and wildlife of the Pacific Northwest. Not long ago, the Columbia Basin would annually see millions of adult salmon and steelhead swimming back from the Pacific Ocean. Chinook, or King salmon, are the largest and richest of the salmonid species. They are also the primary food source (roughly 80 percent of their diet) of endangered Southern Resident orcas. Columbia Basin chinook can spend up to five years in the Pacific Ocean before they return to freshwater to spawn.

Today, however, these fish are in crisis - thirteen Columbia Basin populations are at risk of extinction. The dams and their reservoirs harm and kill salmon and steelhead in numerous ways, including by elevating water temperatures. This situation is being made worse - and the need for meaningful action more urgent - due to the changing climate. These reservoirs warm water above the temperatures of freely flowing rivers by creating large, slow-moving pools that absorb large amounts of solar radiation. These bodies of water also inundate and destroy diverse micro-habitats that healthy rivers support, including cold-water refuges that salmon and steelhead rely upon during their migration in summer months. When available, these vital pockets of cold water can enable adult (moving upstream) and juvenile (moving downstream) fish to rest and recover before continuing their migration. Rising temperatures and reductions in snowpack in recent decades due to climate change has resulted in lower survival and reproductive success for salmon and steelhead.

Temperature affects salmon behavior, reproduction, and survival. According to the National Wildlife Federation, the optimum water temperature range for most salmon is approximately 55 to 64 degrees Fahrenheit¹. While different stocks and species of salmon and steelhead may have different requirements and tolerances, the National Ocean and Atmospheric Administration indicates that Chinook salmon, for example, prefer/require certain water temperatures for all phases of their life history: spawning, egg survival, smoltification, and migration²:

Influence of water temperatures on Chinook salmon spawning and egg incubation:

• Upstream migration will cease if temperatures are below 3.3°C (37.94°F) or above 20°C (68°F).
• The majority of spawning may occur between 6°C (42.8°F) and 15 °C (59°F)
• The optimal temperature range for egg survival is 8°C (46.4°F) to 12°C (53.6°F).
• The optimal temperature range for development to the alevin (larval stage after hatching before yolk absorption stage) is 4°C (39.2°F) to 8°C (46.4°F)

Influence of water temperatures on smoltification by Chinook salmon:

• Water temperatures above 14°C (57.2°F) and below 7°C (44.6°F) can cause mortality in fry.
• High (sub-lethal) water temperatures accelerate growth of fry, but can also result in increased susceptibility to disease.
• High temperatures can lead to early seaward emigration by influencing physiology.

The lower Snake River dams regularly drive water temperatures above 68°F in the summer for weeks or more at a time. Last year, for example, from June through September, all four lower Snake River reservoirs had waters above 68°F for between 40 to 67 days. The Ice Harbor Dam reservoir registered the highest temperature last summer at 73.22°F on July 18, 2021.

Lower Snake River dam removal will deliver big survival benefits to endangered salmon and steelhead

Columbia Riverkeeper, an SOS member organization, published this analysis - White Paper: Computer modeling shows that Lower Snake River dams caused dangerously hot water for salmon in 2015. This analysis shows how a restored lower Snake River would flow freely, absorb far less sunlight and remain much cooler through the summer. Considerably cooler waters would deliver big benefits to migrating juvenile and adult fish populations – leading to increased survival and reproductive success (more information here).

Currently, we are seeing water temperatures below the 10-year average for this time of year in both the lower Snake and Columbia Rivers due mainly to cool weather and a relatively good snowpack. While salmon returning this spring to spawn are benefiting from these cold water conditions, we expect these temperatures to rise as the summer advances.

The Snake River Basin historically (before the dams) annually produced millions of returning adult salmon and steelhead. It supported nearly half of all the spring chinook that returned to the Columbia Basin overall. Notably, these spring chinook are very important to Southern Resident orcas. Before construction of the dams, they were available as large, numerous, and fat-rich prey for the Southern Resident orcas during the winter months when there are few other fish.

Restoring the lower Snake River through dam removal is our very best river and salmon restoration opportunity anywhere on the West Coast today. Scientists predict it could annually produce between 600K and 1.1M adult spring chinook entering the mouth of the Columbia River in the spring and summer months. Increased adult returns of Snake River sockeye, fall chinook, and steelhead would add significantly to these anticipated numbers.

References:

1. The National Wildlife Federation: Chinook Salmon
2. National Oceanic and Atmospheric Administration: The Influence of In-stream Habitat Characteristics on Chinook Salmon (Oncorhynchus tshawytscha) (November, 2002)

LINKS TO RECENT NEWS:

• The White House Council on Environmental Quality: Columbia River Basin Fisheries here - Working Together to Develop a Path Forward. (March 28, 2022)
• The Seattle Times: Removing Lower Snake River dams offers best chance for salmon recovery – at steep price, report says. (June 9, 2022)
• Press Release: The Confederated Tribes of the Umatilla Indian Reservation responds to draft Murray-Inslee Report on Lower Snake River Dams. Honor the treaties. Protect our salmon. Breach the dams.(June 9, 2022)
• Press Release: Nez Perce Tribe Calls for National Leadership from the Administration and Congress: Murray-Inslee Report on Replacing the Service of the Lower Snake River Dams. (June 9, 2022)
• Press Release: Yakama Nation Responds to Murray-Inslee Draft Salmon Report -- Tribe views near-term dam removal as critical to salmon survival in the Columbia Basin (PDF, June 9, 2022)
• Everett Herald Guest Opinion: Don’t fall for TV ads’ climate case for Snake dams (June 5, 2022)
• Columbian Editorial: In Our View: Snake River dams report leaves many questions (June 13, 2022)
• Seattle Times Editorial: A herculean, worthwhile task before breaching Lower Snake River Dams (June 16, 2022)

 Martha Campos is the Hot Water Report Coordinator with Save Our wild Salmon this summer while she resides on Kizh/Tongva ancestral lands in California. Martha holds a BA from the University of California, Davis in Native American Studies (and two minors: Environmental Policy, Analysis, and Planning and Climate Science and Policy) and is a queer, non-binary person of color with ancestral roots in Mexico.

I. INTRODUCTION

Welcome to Save Our wild Salmon’s Hot Water Report 2022.

During the summer, this weekly report will provide an update on real-time water temperatures in the lower Snake and Columbia River reservoirs via graphs and analyses, a summary of the highest weekly water temperatures at the forebay/reservoir of each dam, and the status of adult returns for different salmon and steelhead populations as they make their way back to their natal spawning grounds. We’ll hear first-hand from scientists, Tribal members, fishing guides, advocates, and other experts about the challenges facing the Columbia and Snake Rivers - and our opportunities to improve and restore them - in order to recover healthy, resilient fish populations and the benefits they deliver to the Northwest’s culture, economy, and ecology.

The once-abundant anadromous fish populations of the Columbia-Snake River Basin are struggling to survive today in large part due to multiple harms caused by the system of federal dams and reservoirs. The federal hydro-system creates conditions that harm and kill both juvenile and adult fish, including by elevating water temperatures in large, stagnant reservoirs in the summer months. These cold-water fish begin to suffer harmful effects when water temperatures exceed 68° Fahrenheit. The longer and the higher these temperatures rise above 68°F, the greater the harm, including: migration disruption, increased metabolism, increased susceptibility to disease, reduced fecundity or reproductive potential (by reducing egg viability), suffocation (warm water carries less oxygen), and in the worst case - death.

These harmful hot waterepisodes above 68°F in the Columbia and Snake Rivers are increasing in duration, frequency, and intensity. Our changing climate is making a bad situation for the Northwest’s iconic fish worse. Our region and nation must take urgent action to maintain cool water temperatures - or we will lose these species forever. Restoring a freely flowing lower Snake River by removing its four federal dams is likely our only option to address high water temperatures in this 140-mile stretch of river running through southeast Washington State. Restoring the Snake River is one essential element of what must be a larger regional strategy to protect and rebuild healthy, abundant salmon and steelhead populations in order to benefit other fish and wildlife populations, including critically endangered Southern Resident orcas, to uphold our nation’s promises to Native American tribes, and to ensure prosperous communities across the Northwest.

The Hot Water Report is a joint project of the Save Our wild Salmon Coalition, Columbia Riverkeeper, American Rivers, Endangered Species Coalition, Environment Washington, Idaho Conservation League, Idaho Rivers United, Idaho Wildlife Federation, National Resource Defense Council, National Wildlife Federation, Nimiipuu Protecting the Environment, Northwest Sportfishing Industry Association, Sierra Club, Snake River Waterkeeper, and Wild Steelhead Coalition.

II. READING THE DATA - Lower Snake and Columbia River Temperatures

The daily mean temperature at the four reservoir forebays (immediately upstream from the dam) in the lower Snake River (above) and the lower Columbia River (below) for 2022 is represented with solid lines and their 10-year average (2012 - 2022) temperatures with dashed lines of the same color. The dotted line across the graph represents the 68°F “harm threshold” for adult and juvenile fish. Salmon and steelhead begin to suffer harmful effects when water temperatures exceed 68° Fahrenheit. The longer temperatures remain above 68°F and the higher the temperatures rise above 68°F, the more severe the potential effects, including: increased metabolism, increased susceptibility to disease, reduced fecundity or reproductive potential, and/or death.

Since April, temperatures in the lower Snake River and the lower Columbia River reservoirs have steadily moved upward. During April and May, trends have tracked closely with the 10-year average. In June, however, water temperatures have dropped considerably below this average. This is good news for cold-water species like salmon and steelhead, though we expect these temperatures will rise considerably in these reservoirs as the summer progresses. This week, the reservoir behind the Little Goose Dam had the highest mean temperature of 63.68°F and the Ice Harbor Dam’s reservoir had the second highest mean temperature of 62.96°F.

A note on data information: The mean water temperature data from these reports comes from the USGS Current Conditions for Washington State and the 10-year average water temperature data comes from the Fish Passage Center. There is no available data for Lower Monumental's 10-year average water temperature. Graphs and tables were assembled by SOS Staff.

 III. WEEKLY HIGH TEMPERATURES: 6/21-7/4

On the lower Snake River this week, the reservoir behind the Little Goose Dam registered the highest temperature at 64.22°F, followed closely by the Lower Monumental reservoir with 63.32°F. 

On the lower Columbia River, the reservoirs behind the Bonneville Dam registered the highest temperature at 63.14°F.

 IV. Senator Murray and Governor Inslee’s ‘Lower Snake River Dams Benefit Replacement Report’ 

This year, the Northwest and the nation face a critical window of opportunity to decide, develop, and deliver a comprehensive regional plan to restore the lower Snake River and invest in its communities. Restoring the lower Snake River is our only realistic option for addressing its dangerously high water temperatures in the summer months. River restoration will help address other dam-caused problems created for fish by, for example, reducing predator populations, increasing current velocity, decreasing juvenile fish migration times to the estuary, and more.

July 31 deadlines loom for (i) Murray/Inslee Snake River salmon initiative and (ii) the Biden Administration’s settlement discussions: Last October, Sen. Patty Murray and Gov. Jay Inslee announced their next steps to develop an action plan to protect and restore Snake River salmon and steelhead, and invest in the region's communities. Earlier this month, Sen. Murray and Gov. Inslee released their draft “Lower Snake River Dams Benefit Replacement Report,” which confirms that the dams’ current services can be fully, feasibly, and affordably replaced. A public comment period on the Draft Report is open now through July 11. Information about the Murray/Inslee Snake River initiative and the draft ‘Lower Snake River Dams’ Benefits Replacement Report’ can be found here.

Costs & Benefits of Salmon Recovery

The findings from Senator Murray and Governor Inslee’s draft report lay the foundation for developing a comprehensive solution to restore the lower Snake River and its salmon, help critically endangered orcas, uphold our promises to Tribal Nations, create economic opportunities, and upgrade costly and aging energy, irrigation, and transportation infrastructure.

The report concludes that all of the services the dams provide can be replaced and doing so would provide tangible economic opportunities. However, the range of costs of replacing the services of the lower Snake River dams as presented in the draft report to Murray and Inslee is $10.3-$27.2 billion over 50 years. This estimate does not consider or compare that with the current costs of maintaining the aging infrastructure of the four lower Snake River dams, the future costs avoided by dam removal, nor of the monetized and non-monetary benefits of life without the lower Snake River dams.

Below, we present background information on the benefits of restoring a freely flowing lower Snake River by removing its four federal dams:

DAM REMOVAL IS A COST-EFFECTIVE SALMON RECOVERY STRATEGY

• Since 1980, Northwest electric consumers have paid $26.1 billion (in 2022 $$) on plans to recover fish and wildlife; most of this has gone to implement salmon recovery plans.
• However, these plans have not achieved recovery goals for Snake River salmon and steelhead as they are on the path to extinction. Last year, thousands of returning adult salmon died before they could spawn due to the deadly hot waters in lower Columbia and lower Snake River reservoirs. Only 4 adult sockeye salmon survived to swim into their spawning grounds in the Stanley Basin in central Idaho after struggling past eight dams and warm and stagnant reservoirs downstream and steelhead saw the lowest returns in history in 2021, forcing emergency fishing closures in Washington and Oregon.
• If the lower Snake dams remain, these costs not only continue, but almost certainly increase as more extensive and expensive measures are introduced. The cheaper option, by far, is to do what salmon scientists call for—restore a free-flowing lower Snake River and invest in comprehensive, science-based salmon recovery plans.

REPLACING THE DAMS’ POWER PRODUCTION ADDS VALUE

• The dams’ cost of operation, maintenance, and capital, which is currently about $151 million annually, will only increase over time. Additional capital investments will be required to keep the dams operating, e.g., the replacement of costly items like 21 of their 24 aging turbine generators is estimated to cost more than $600 million.
• At the same time, the power output of the dams is likely to decrease as a result of changes in hydro operations to benefit fish and, potentially, the impacts of climate change on the amount of water in the river.
• Investing in clean energy resources would provide more value than the output of the lower Snake dams. Renewable energy technology costs are expected to continue declining, meaning replacement of the energy services of the dams will be less costly than today’s projections. Modeling of renewable energy technology costs from the National Renewable Energy Laboratory shows declining costs for solar, wind, and battery systems through 2030 and beyond. A recent Lawrence Berkeley National Laboratory analysis found that current supply chain and inflation issues shouldn’t change that outlook.

OTHER BENEFITS OF A FREE-FLOWING SNAKE RIVER

• The draft report estimates that recovery of these stocks would boost annual tribal harvest by at least 29%. Tribal fishing—commercial and subsistence—has been gravely impacted by declines in salmon and steelhead (and lamprey and other species).
• More fish will support more fishermen. As late as 1978, there were more than 3,000 Washington-based commercial salmon trollers. Today, with depressed salmon populations, there are barely 100—a loss of 6,000 jobs in the fishing fleet and more in onshore businesses providing services, supplies, and equipment to fishermen.
• A restored salmon fishery could generate an additional $1 billion annually in income for recreational fishing industries and support up to 25,000 more jobs, according to the draft report. Opportunities for recreational fishing, jobs, and economic activity they generate, have likewise been limited by the dearth of salmon.

SALMON ARE CRITICAL TO OUR ECOSYSTEM

As salmon, a keystone species, disappear–our Pacific Northwest ecosystems, culture and economies are hugely impacted. Our ocean, rivers, forests, and at least 137 wildlife species in the Pacific Northwest, including Southern Resident Orcas, who rely on vital nutrients from salmon. The enormous benefit that salmon provides for countless species and the overall health and function of the Pacific Northwest ecosystem is irreplaceable and incalculable.

WE CAN AFFORD SALMON RECOVERY

We can, economically speaking, afford a salmon recovery path that protects salmon and orca from extinction. This is a historic opportunity to lead the largest salmon recovery by developing and investing in new, comprehensive, science-based solutions that restore the Snake River; save salmon, steelhead, and orca from extinction; honor tribal treaty rights and uphold our promises to Northwest Tribes; creates jobs and economic opportunities; and upgrades the aging energy, irrigation, and transportation infrastructure.

LINKS TO RECENT NEWS:

• The Herald Letters to the Editor: Snake River dams’ energy is replaceable; salmon species isn’t (June 19, 2022)
• Seattle Times Letters to the Editor: Snake River Dams ‘Status quo is not an option’ (June 24, 2022)
• Public News Service: Public Comment Encouraged on Snake River Dams Removal Plan (June 24, 2022)
• Oregonian: Several hundred take to Willamette River, Willamette Park to protest 4 Snake River dams (June 25, 2022)
• Seattle Times: Dam politics: Why public power utilities are pouring cash into the campaign to support Lower Snake River dams (June 26, 2022)
• The Herald Letters to the Editor: Snake River dams aren’t worth loss of salmon species (June 26, 2022)
• The Herald Letters to the Editor: Saving salmon requires a break from status quo(June 26, 2022)
• Northwest Sportsman Magazine: Rally Held For Salmon, Breaching Lower Snake Dams (June 27, 2022)
• Idaho Statesman: Making ourselves whole by breaching Lower Snake River Dams, restoring salmon to Idaho (July, 1, 2022)

 Martha Campos is the Hot Water Report Coordinator with Save Our wild Salmon this summer while she resides on Kizh/Tongva ancestral lands in California. Martha holds a BA from the University of California, Davis in Native American Studies (and two minors: Environmental Policy, Analysis, and Planning and Climate Science and Policy) and is a queer, non-binary person of color with ancestral roots in Mexico.

I. INTRODUCTION

Welcome to the Hot Water Report 2022, Issue 11, our final issue for this summer!

This summer, we’ve provided updates on real-time water temperatures in the lower Snake and Columbia River reservoirs via graphs and analyses, a report on the highest weekly water temperature at the forebay/reservoir of each dam, and the status of adult returns for the different salmon and steelhead populations as they return to their natal spawning grounds. We heard first-hand from scientists and other experts about challenges facing the Columbia and Snake rivers - and the opportunities we have to restore health to these rivers, and help recover healthy, resilient fish populations and the many benefits they deliver to the Northwest’s culture, economy, and ecology.

The once-abundant anadromous fish populations of the Columbia-Snake River Basin are struggling to survive today in large part due to multiple harms caused by the system of federal dams and reservoirs. The federal hydro-system creates conditions that harm and kill both juvenile and adult fish, including by elevating water temperatures in large, stagnant reservoirs in the summer months. These cold-water fish begin to suffer harmful effects when water temperatures exceed 68° Fahrenheit.

Today, these harmful hot waterepisodes above 68°F in the Columbia and Snake Rivers are increasing in duration, frequency, and intensity. Our changing climate is making a bad situation for the Northwest’s iconic fish worse. Our region and nation must take urgent action to maintain cool water temperatures - or we will lose these species forever. Restoring a freely flowing lower Snake River by removing its four federal dams is our only feasible option to address high water temperatures in this 140-mile stretch of river running through southeast Washington State. Restoring the Snake River is one essential element of what must be a larger regional strategy to protect and rebuild healthy, abundant salmon and steelhead populations in order to benefit other fish and wildlife populations, including critically endangered Southern Resident orcas, to uphold our nation’s promises to Native American tribes, and to ensure prosperous communities across the Northwest.

The Hot Water Report 2022 is a joint project of the Save Our wild Salmon Coalition, Columbia Riverkeeper, American Rivers, Endangered Species Coalition, Environment Washington, Idaho Conservation League, Idaho Rivers United, Idaho Wildlife Federation, National Resource Defense Council, National Wildlife Federation, Nimiipuu Protecting the Environment, Northwest Sportfishing Industry Association, Sierra Club, Snake River Waterkeeper, Spokane Riverkeeper, Wild Orca, and Wild Steelhead Coalition.

II. READING THE DATA - Highest Water Temperatures on Lower Snake and Columbia River in 2022

This year, we experienced another summer of hot water temperature in the lower Snake River and the lower Columbia River. From mid-July to September, all four lower Snake River’s reservoirs had waters above the 68°F “harm threshold” for adult and juvenile fish. Salmon and steelhead begin to suffer harmful effects when water temperatures exceed 68°F.

The longer temperatures remain above 68°F and the higher the temperatures rise above 68°F, the more severe the potential effects to salmon and steelhead, including: migration disruption, increased metabolism, increased susceptibility to disease, reduced reproductive potential (by reducing egg viability), suffocation (warm water carries less oxygen), and in the worst case - death. Specifically, as temperatures reach 70°F, salmon start to form fungus on their bodies and are more susceptible to diseases. At 71-72°F, salmon stop migrating and at 73°F, salmon die (see this 2-minute video from National Wildlife Federation for more information).

Hot Water Temperatures in the lower Snake River: On July 14, 2022, the Little Goose reservoir was the first to reach 68°F and registered above 68°F for 48 days. On August 19, 2022, the reservoir behind the Ice Harbor Dam registered the highest temperature we have seen this summer – 72.32°F. In addition, the Ice Harbor reservoir had temperatures reaching above 68°F for 46 days.

The Lower Granite Dam’s reservoir had the second highest temperature of 71.96°F on August 31, 2022, and the reservoir registered above 68°F for 26 days. Lastly, the Lower Monumental reservoir reached a high temperature of 70.88°F on multiple days in mid-August.

By restoring this 140-mile stretch of the lower Snake River through dam removal, computer models show that, while temperatures in a freely flowing river may spike above 68 degrees periodically, they will quickly return to the cool temperatures that salmon and steelhead need to survive and migrate. A free-flowing lower Snake River would not absorb the same amount of solar radiation. Considerably cooler waters deliver big benefits to migrating juvenile and adult salmon and steelhead populations—leading to increased survival and reproductive success (see Issue 4 for more information on computer models showing the improvement of water temperatures without the lower Snake River dams). 

Hot Water Temperatures in the lower Columbia River: The water temperatures in the lower Columbia River gives us an in-depth look at the lethal conditions and temperatures that Snake River salmon and steelhead must migrate through. Endangered Snake River salmon and steelhead have to cross eight dams and reservoirs to reach the ocean and then again as they return to their spawning grounds. In addition, the dams and their hot water reservoirs can kill up to 70% of out-migrating Snake River juvenile fish before they ever reach the ocean.

Dave Johnson, Department Manager of the Nez Perce Tribe’s Department of Fisheries Resources Management, recently stated, "The fish evolutionarily are developed to make it down to the ocean in a certain amount of time. We've extended that period of time to a month [with the four lower Snake River dams in place] so they run out of reserves, they run out of their food by the time they reach the ocean” (see Issue 6for more information).

As we see from the “Highest Water Temperatures on the Lower Columbia River” table above, the John Day reservoir reached a high temperature of 73.04°F on August 29, 2022. For endangered Snake River salmon and steelhead, the dams and the reservoirs have extended and changed their migration journey and continuously change water temperatures as the summer progresses.

A note on data information: The water temperature data from these reports comes from the USGS Current Conditions for Washington State. Tables were assembled by SOS Staff.

 III. A Look at Snake River Wild Salmon & Steelhead Adult Returns as of September 14, 2022

The Snake River's anadromous fish populations have been on a steady downward trajectory across the last several decades. These salmon and steelhead face multiple obstacles, including dangerously hot water in the summer months in the Snake River reservoirs. Below, we present background information on and current status of native fish returns, including (1) wild Snake River Spring/Summer Chinook, (2) wild steelhead, and (3) wild/natural sockeye. We will also look at how the historical and current numbers of returning adults compare to established recovery goals - the adult returns deemed necessary to recover these populations and remove them from the Endangered Species Act list.

In summary - since the four lower Snake River dams were built, over 60 years ago, Snake River salmon and steelhead populations have been in a steady decline. Even before the dams were built, it was projected that lower Snake River dams would cause salmon and steelhead to go extinct. Each year, these fish return (far) below the recovery goals necessary to remove them from the Endangered Species Act list. Without immediate and meaningful conservation actions, scientists predict we will lose these populations forever.

(i) Snake River Spring/Summer Chinook:

• Endangered Species Act Status: Threatened (listed in 1992)
• Historical Annual Return: Over 2 million¹
• Recovery Goal: Escapement of 127,000 wild adults per year
  Estimated 2022 Returns: 15,678 (estimated as 20% of total run in season)
• Analysis: Spring/summer chinook were once the Pacific Northwest’s most widely distributed and abundant salmon, numbering in the millions. The Salmon River alone produced 39 percent of the spring chinook and 45 percent of the summer chinook in the entire Columbia River Basin.¹ Currently, an estimated 15,678 wild spring/summer Chinook have returned from the ocean to their upriver spawning grounds in Idaho.

(ii) Snake River Steelhead

• Endangered Species Act Status: Threatened (listed in 1997)
• Historical Annual Return: Over 1 million¹
• Recovery Goal: Escapement of 104,500 wild adults per year
• Estimated 2021/2022 Returns: 10,998
• Analysis: An estimated 10,998 wild steelhead have returned from the ocean to their upriver spawning grounds in Idaho in 2021/2022, which is well below the 10-year average of 22,735 and the recovery goal of 104,500 wild steelhead adults per year.

(iii) Snake River Sockeye

• Endangered Species Act Status: Endangered (listed in 1991)
• Historical Annual Return: Over 100,000+/yr to central Idaho’s high mountain lakes¹
• Recovery Goal: 9,000 wild adults per year to the Stanley Basin
• Estimated 2022 Returns: 39 wild/natural-origin sockeye returned to the Stanley Basin 
• Analysis: Historic runs to Idaho’s high mountain lakes used to be over 100,000+ sockeye per year but have also severely declined over the years.¹ The 10-year average for sockeye returning to the Stanley Basin in central Idaho is just 80 fish and a recovery goal of 9,000 wild sockeye per year. Only 39 wild adult sockeye salmon survived to swim into their spawning grounds in the Stanley Basin in central Idaho after struggling past eight dams and warm and stagnant reservoirs downstream.

Given the current returns for wild Snake River chinook, steelhead, and sockeye, these fish are much closer to extinction than recovery. Snake River salmon and steelhead are on the brink of extinction today. The health of these populations has plummeted over time from historic levels that were once in the hundreds of thousands or millions, depending on the particular population. Snake River salmon and steelhead populations have been in a steady decline for many years; they are returning each year below their historical and recovery levels.

This summer, current salmon and steelhead returns are higher than those of the past 5 years as these fish encountered suitable water temperatures in the lower Snake River reservoirs prior to mid-July. However, recent heat waves caused temperatures to rise above 68°F – causing migration disruption and dangerous water conditions for salmon and steelhead. Restoring a freely flowing lower Snake River by removing its four federal dams is our only option to address high water temperatures and their impacts on wild salmon and steelhead, as well as recovering salmon and steelhead from extinction.

In the Hot Water Report Issue 6, we asked Jay Hesse, Director of Biological Services of the Nez Perce Tribe’s Department of Fisheries Resources Management, about this year’s current salmon returns:

“The increase in Snake River basin natural-origin spring/summer returns occurring this year (2022) is welcomed and consistent with our expectations for improved survival under good ocean conditions and high spill hydro-operations. However, it is important to understand that while the 2022 return is an improvement over recent years, abundance remains precariously low and well below criteria for Endangered Species Act-delisting - let alone our goals representing healthy and harvestable status.”

In addition, the Nez Perce Tribe’s Quasi-Extinction Threshold Analysis indicates that wild spring Chinook and steelhead populations in the Snake River Basin have crossed a critical threshold known as the Quasi-Extinction Threshold, signaling they are nearing extinction. And without immediate intervention, within the next 3-4 years, many may not persist.

A note on data information: The Snake River Wild Salmon returns data comes from the Fish Passage Center and Idaho Department of Fish and Game. Tables and graphs were assembled by Idaho Rivers UnitedStaff.

 IV. Urgency To Restore The Lower Snake River

With U.S. Senator Patty Murray and Washington State Governor Jay Inslee's long-anticipated final Lower Snake River Dam Benefits Replacement Report and recommendations, we’re entering a critical new phase of work to protect and recover endangered Snake River salmon and steelhead populations and aid endangered, salmon-dependent Southern Resident orcas.

Senator Patty Murray and Governor Jay Inslee’s recommendations include this essential conclusion: “The science is clear that – specific to the Lower Snake River – breach of the dams would provide the greatest benefit to the salmon. Salmon runs in the Lower Snake River are uniquely impacted by the dam structures relative other watersheds, and the waters of the Lower Snake River have unique potential for robust aquatic ecosystem and species recovery.”

Sen. Murray and Gov. Inslee announced key action items for the Snake River as one part of a larger set of important priorities and next steps, for state and federal governments working with Tribes and stakeholders to develop and implement a comprehensive regional solution to restore this historic river, protect and rebuild abundant salmon populations, uphold our nation’s promises to Tribes - and meet the needs of communities.

Our way forward – to plan and implement (i) the replacement of services and (ii) the removal of the lower Snake River dams – will require significant collaborative planning, policy, advocacy, and state and federal investments. With salmon and steelhead populations and the Southern Resident orcas struggling for survival today, immediate and sustained action is essential.

References:
1. The Salmon Community's View: The Status of wild salmon and steelhead populations in the Columbia and Snake River Basin (2016) 

Hot Water Report 2022

Throughout our 2022 Hot Water Reports, we have identified key solutions and strategies to salmon recovery and restoring the lower Snake River. To protect, restore, and reconnect the freshwater habitats that salmon and steelhead depend upon.

View each of the Hot Water Reports here: HOT WATER REPORT– COMPILED.

Martha Campos is the Hot Water Report Coordinator with Save Our wild Salmon this summer while she resides on Kizh/Tongva ancestral lands in California. Martha holds a BA from the University of California, Davis in Native American Studies (and two minors: Environmental Policy, Analysis, and Planning and Climate Science and Policy) and is a queer, nonbinary person of color with ancestral roots in Mexico.

I. INTRODUCTION

Welcome to Save Our wild Salmon’s Hot Water Report 2022.

During the summer, this weekly report provides an update on real-time water temperatures in the lower Snake and Columbia River reservoirs via graphs and analyses, a summary on the highest weekly water temperatures at the forebay/reservoir of each dam, and the status of adult returns for different salmon and steelhead populations as they make their way back to their natal spawning grounds. We’ll hear first-hand from scientists, Tribal members, fishing guides, advocates, and other experts about the challenges facing the Columbia and Snake rivers - and our opportunities to improve and restore them - in order to recover healthy, resilient fish populations and the benefits they deliver to the Northwest’s culture, economy, and ecology.

The once-abundant anadromous fish populations of the Columbia-Snake River Basin are struggling to survive today in large part due to multiple harms caused by the system of federal dams and reservoirs. The federal hydro-system creates conditions that harm and kill both juvenile and adult fish, including by elevating water temperatures in large, stagnant reservoirs in the summer months. These cold-water fish begin to suffer harmful effects when water temperatures exceed 68° Fahrenheit. The longer and the higher these temperatures rise above 68°F, the greater the harm, including: migration disruption, increased metabolism, increased susceptibility to disease, reduced reproductive potential (by reducing egg viability), suffocation (warm water carries less oxygen), and in the worst case - death.

Today, these harmful hot waterepisodes above 68°F in the Columbia and Snake Rivers are increasing in duration, frequency, and intensity. Our changing climate is making a bad situation for the Northwest’s iconic fish worse. Our region and nation must take urgent action to maintain cool water temperatures - or we will lose these species forever. Restoring a freely flowing lower Snake River by removing its four federal dams is our only feasible option to address high water temperatures in this 140-mile stretch of river running through southeast Washington State. Restoring the Snake River is one essential element of what must be a larger regional strategy to protect and rebuild healthy, abundant salmon and steelhead populations in order to benefit other fish and wildlife populations, including critically endangered Southern Resident orcas, to uphold our nation’s promises to Native American tribes, and to ensure prosperous communities across the Northwest.

The Hot Water Report 2022 is a joint project of the Save Our wild Salmon Coalition, Columbia Riverkeeper, American Rivers, Endangered Species Coalition, Environment Washington, Idaho Conservation League, Idaho Rivers United, Idaho Wildlife Federation, National Resource Defense Council, National Wildlife Federation, Nimiipuu Protecting the Environment, Northwest Sportfishing Industry Association, Sierra Club, Snake River Waterkeeper, Spokane Riverkeeper, Wild Orca, and Wild Steelhead Coalition.

II. READING THE DATA - Lower Snake and Columbia River Temperatures

Introduction: The daily mean temperature at the four reservoir forebays (immediately upstream from the dam) in the lower Snake River (above) and the lower Columbia River (below) for 2022 is represented with solid lines and their 10-year average (2012 - 2022) temperatures with dashed lines of the same color. The dotted line across the graph represents the 68°F “harm threshold” for adult and juvenile fish. Salmon and steelhead begin to suffer harmful effects when water temperatures exceed 68° Fahrenheit. The longer temperatures remain above 68°F and the higher the temperatures rise above 68°F, the more severe the potential effects, including: increased metabolism, increased susceptibility to disease, reduced reproductive potential, and/or death (see Issue 1 for more detailed information).

Discussion: Since April, temperatures in the lower Snake River and the lower Columbia River reservoirs have steadily moved upward. During April and May, trends have tracked closely with the 10-year average. In June, however, water temperatures dropped considerably below this average. This was good for cold-water species like salmon and steelhead, but since July, temperatures have reached and exceeded the 68°F “harm threshold” in the reservoirs on the lower Snake and Columbia River. Below, we present the highest temperatures for each reservoir on the lower Snake and Columbia River. 

A note on data information: The mean water temperature data from these reports comes from the USGS Current Conditions for Washington State and the 10-year average water temperature data comes from the Fish Passage Center. There is no available data for Lower Monumental 10-year average water temperature. Graphs and tables were assembled by SOS Staff.

 III. WEEKLY HIGH TEMPERATURES: 8/16-8/29

Harmful water temperatures in the lower Snake River reservoirs: This week, all reservoirs exceeded 68 degrees. The Little Goose Dam reservoir has spent 45 days above 68°F and similarly, the Ice Harbor Dam spent 44 consecutive days above 68°F.

The reservoir behind Ice Harbor Dam registered the highest temperature at 72.32°F on August 19th - significantly above the level that cold-water fish require. The waters behind Lower Monumental Dam registered the second highest temperature at 70.88°F.

This week, on the lower Columbia River, all reservoirs peaked over 68°F. The reservoirs behind the John Day Dam registered the highest temperature: 73.04°F.

 IV. Sen. Murray and Gov. Inslee’s Final 'Lower Snake River Dams' Benefit Replacement Report' and Recommendations 

Last year Washington Sen. Patty Murray and Gov. Jay Inslee announced a process that “evaluated the feasibility of breaching the Lower Snake River Dams as a way of protecting endangered salmon and steelhead species.” In June, they released a draft “Lower Snake River Dams Benefit Replacement Report”, which confirmed that the dams’ current services can be fully, feasibly, and affordably replaced or their loss mitigated.

On August 25, 2022, Sen. Murray and Gov. Inslee released their recommendationson salmon recovery and the dams, as well as a final report on replacing the dams’ services. Sen. Murray and Gov. Inslee stated they are committed to action that will make dam breaching viable, noting that the extinction of salmon and the orca that feed on them is “categorically unacceptable.” They stressed the need for prompt action to replace—or mitigate the loss of —the dams’ services in advance of breaching. In addition, the final report affirmed that Columbia/Snake salmon and steelhead are in real peril of extinction, that the lower Snake dams are a major source of their endangerment and their removal is an essential part of a larger strategy to protect and restore abundant, harvestable populations.

In a statement, Gov. Inslee said that the status quo is not an option and that saving salmon is imperative. “The state and federal governments should implement a plan to replace the benefits of the Lower Snake River Dams to enable breaching to move forward,” Inslee said. “We will not permit Washington state to lose its salmon,” the governor and senator promised in their recommendations.

The senator and governor’s recommendations emphasize three key themes:

• Status quo is not an option. Changing economic, energy, and climate conditions require leaders to plan for changing circumstances in the Columbia Basin region during the coming decades.
• Saving salmon and other iconic species in the Columbia Basin is imperative. The scientific review affirms that breaching these specific dams offers the greatest benefit to the salmon.
• The impacts and benefits of breaching the dams are significant, but they can and must be mitigated or replaced.

Information about the Murray/Inslee Snake River initiative and the final ‘Lower Snake River Dams’ Benefits Replacement Report’ and recommendations can be found here.

A Path Towards Salmon Recovery and the Removal of the Lower Snake River:

Sen. Murray and Gov. Inslee’s final report and recommendations have clearly stated our region should move forward with a plan to replace the benefits of the lower Snake River dams, and implement a new comprehensive approach to protect and recover salmon and steelhead populations facing extinction today.

“The science is clear that – specific to the Lower Snake River – breach of the dams would provide the greatest benefit to the salmon. Salmon runs in the Lower Snake River are uniquely impacted by the dam structures relative to other watersheds,” stated in Sen. Murray and Gov. Inslee’s final recommendations. Their findings lay the foundation for developing a comprehensive solution to restore the lower Snake River and its salmon, help critically endangered orcas, uphold our promises to Tribal Nations, create economic opportunities, and upgrade costly and aging energy, irrigation, and transportation infrastructure.

Sen. Murray and Gov.Inslee recognized that after 20+ years of “implementing mitigation and restoration actions for Snake River salmon and steelhead species, the species are on a downward trajectory. Despite robust levels of assessment and planning, actions have not resulted in responses that would indicate adequate mitigation, let alone levels of recovery.”

“Extinction of salmon, orca, and other iconic species in the Pacific Northwest is categorically unacceptable to us, and we will not permit Washington state to lose its salmon. We must move forward in a way that restores our salmon populations and acknowledges and redresses the harms to Tribes while responsibly charting the course to an energy and economic future for Washington state and the region. It is for these reasons that we previously stated that breaching of the lower Snake River dams should be an option, and why we believe, at the conclusion of this Process, that it must be an option we strive to make viable,” they concluded.

Replacing the lower Snake River dams’ services:

We are now on a path to breaching the four lower Snake River dams and replacing their services as part of a comprehensive plan for salmon restoration in the Columbia Snake River Basin. Sen. Murray and Gov. Inslee committed to developing a plan that requires building new energy, transportation, and irrigation infrastructure “in an effective and efficient manner. We can do so in a manner that is responsible and environmentally safe, that addresses the concerns of communities, and that respects the Treaty rights and cultural imperatives of Tribal sovereigns. But we must do this work.”

Notably, Sen. Murray and Gov. Inslee affirmed that, “The clean energy provided by the Lower Snake River Dams constitutes only a small fraction of the new generating and transmission capacity that our region must build – just over 3.4% according to the most recent E3 report. As such, replacing that capacity does not meaningfully alter what we must already accomplish.”

Sen. Murray and Gov. Inslee further concluded that to make dam removal a “realistic and actionable option, we must focus on short- and medium-term actions to invest in the region’s transportation network and electrical grid….Importantly, we must also aggressively pursue projects and initiatives to restore habitat and support salmon recovery throughout the Columbia River Basin and the Puget Sound.”

Senator Murray and Governor Inslee’s commitments to Salmon Recovery:

Sen. Murray and Gov. Inslee have both committed to develop and “implement a plan to replace the benefits of the Lower Snake River Dams to enable breaching to move forward."

For example, Sen. Murray and Gov. Inslee have committed to:

• Work with Tribes, co-managers, and impacted stakeholders to determine a plan to more efficiently and effectively distribute salmon funding.
• Leverage the historic investments made in the Infrastructure Investment and Jobs Act and the Inflation Reduction Act to support energy replacement, infrastructure enhancement, and salmon recovery and habitat restoration.
• Governor Inslee’s 2023 legislative agenda will include new, robust salmon recovery investments, legislation, and other actions to improve the health of our oceans, coastal areas, and rivers, including the Snake.
• The Lower Snake River Dams Benefit Replacement Report identifies the need for further detailed transportation analysis, focusing primarily on potential highway and road impacts that would result from the elimination of barging on the lower Snake River. Governor Inslee will seek such an analysis from the Washington State Department of Transportation.

The Urgency to Restore Salmon and Steelhead: 

As salmon and steelhead (keystone species) decline, our Pacific Northwest ecosystems, culture, and economies are hugely impacted. Our ocean, rivers, forests, and at least 137 wildlife species in the Pacific Northwest, including Southern Resident Orcas, rely on vital nutrients from salmon. The enormous benefit that salmon provides for countless species and the overall health and function of the Pacific Northwest ecosystem is irreplaceable and incalculable.

But salmon and steelhead are running out of time. The federal hydro-system creates conditions that harm and kill juvenile and adult fish, including elevating water temperatures in large, stagnant reservoirs in the summer months. This summer, the lower Snake River have reached temperatures between 68°F - 72.32°F – causing dangerous conditions for salmon and steelhead. In addition, the Nez Perce Tribe’s Quasi-Extinction Threshold Analysis indicates that wild spring Chinook and steelhead populations in the Snake River Basin have crossed a critical threshold known as the Quasi-Extinction Threshold, signaling they are nearing extinction, and without intervention within the next 3-4 years, many may not persist.

Our region and nation must work together to develop and implement a plan to restore the lower Snake River, honor the treaty rights and other promises made to Northwest tribes, invest in clean energy and upgrade aging infrastructure, and create new economic opportunities for communities across our state and region.

 LINKS TO RECENT NEWS AND INFORMATION:

• Press Release: Inslee statement regarding final report for Join Federal-State Process for salmon recovery in the Columbia Basin 
• Press Release: Senator Murray Statement on Finding of Murray-Inslee Joint Federal-State Process
• Press Release: Governor Kate Brown Commends Washington Leaders for Supporting Collaborative Solution for Columbia Basin Salmon, Steelhead Restoration
• Press Release: Yakama Nation Responds to Final Murray and Inslee Salmon Report 
• Press Release: SNAKE RIVER: Energy, fishing, conservation groups respond to Sen. Murray’s & Gov. Inslee’s presumptive plan for dam replacement
• The New York Times: Breaching Dams ‘Must Be an Option’ to Save Salmon, Washington Democrats Say (August 31, 2022)
• OPB: Benefits of Snake River dams must be replaced before breaching to save salmon, report says (August 25, 2022)
• Spokesman-Review: Murray and Inslee conclude breaching Snake River dams ‘not an option right now,’ while calling status quo unsustainable for salmon (August 25, 2022)
• Seattle Times: Inslee, Murray say Snake River dam removal possible, but not yet(August 25, 2022)
• KREM 2: Inslee, Murray recommend taking action to make breaching Snake River dams a 'viable option' (August 25, 2022)
• Spokesman-Review: Snake River spring Chinook struggling like never before, feds decide against classifying them as ‘endangered’ (August 25, 2022)
• AP News: Columbia River's Salmon Are at the Core of Ancient Religion (August 15, 2022)
• Lewiston Morning Tribune: Guest Opinion: Dugger ‘gas lights’ fish recovery and dam breaching (August 14, 2022)
• My Edmonds News: Activists demonstrate in Edmonds for Snake River dam removal(August 20, 2022)
• Past Hot Water Reports are archived here: Hot Water Reports - Compiled

Martha Campos is the Hot Water Report Coordinator with Save Our wild Salmon this summer while she resides on Kizh/Tongva ancestral lands in California. Martha holds a BA from the University of California, Davis in Native American Studies (and two minors: Environmental Policy, Analysis, and Planning and Climate Science and Policy) and is a queer, nonbinary person of color with ancestral roots in Mexico.

I. INTRODUCTION

Welcome to Save Our wild Salmon’s Hot Water Report 2022.

During the summer, this weekly report provides an update on real-time water temperatures in the lower Snake and Columbia River reservoirs via graphs and analyses, a summary on the highest weekly water temperatures at the forebay/reservoir of each dam, and the status of adult returns for different salmon and steelhead populations as they make their way back to their natal spawning grounds. We’ll hear first-hand from scientists, Tribal members, fishing guides, advocates, and other experts about the challenges facing the Columbia and Snake rivers - and our opportunities to improve and restore them - in order to recover healthy, resilient fish populations and the benefits they deliver to the Northwest’s culture, economy, and ecology.

The once-abundant anadromous fish populations of the Columbia-Snake River Basin are struggling to survive today in large part due to multiple harms caused by the system of federal dams and reservoirs. The federal hydro-system creates conditions that harm and kill both juvenile and adult fish, including by elevating water temperatures in large, stagnant reservoirs in the summer months. These cold-water fish begin to suffer harmful effects when water temperatures exceed 68° Fahrenheit. The longer and the higher these temperatures rise above 68°F, the greater the harm, including: migration disruption, increased metabolism, increased susceptibility to disease, reduced reproductive potential (by reducing egg viability), suffocation (warm water carries less oxygen), and in the worst case - death.

Today, these harmful hot waterepisodes above 68°F in the Columbia and Snake Rivers are increasing in duration, frequency, and intensity. Our changing climate is making a bad situation for the Northwest’s iconic fish worse. Our region and nation must take urgent action to maintain cool water temperatures - or we will lose these species forever. Restoring a freely flowing lower Snake River by removing its four federal dams is our only feasible option to address high water temperatures in this 140-mile stretch of river running through southeast Washington State. Restoring the Snake River is one essential element of what must be a larger regional strategy to protect and rebuild healthy, abundant salmon and steelhead populations in order to benefit other fish and wildlife populations, including critically endangered Southern Resident orcas, to uphold our nation’s promises to Native American tribes, and to ensure prosperous communities across the Northwest.

The Hot Water Report 2022 is a joint project of the Save Our wild Salmon Coalition, Columbia Riverkeeper, American Rivers, Endangered Species Coalition, Environment Washington, Idaho Conservation League, Idaho Rivers United, Idaho Wildlife Federation, National Resource Defense Council, National Wildlife Federation, Nimiipuu Protecting the Environment, Northwest Sportfishing Industry Association, Sierra Club, Snake River Waterkeeper, Spokane Riverkeeper, Wild Orca, and Wild Steelhead Coalition.

  II. READING THE DATA - Lower Snake and Columbia River Temperatures

Introduction: The daily mean temperature at the four reservoir forebays (immediately upstream from the dam) in the lower Snake River (above) and the lower Columbia River (below) for 2022 is represented with solid lines and their 10-year average (2012 - 2022) temperatures with dashed lines of the same color. The dotted line across the graph represents the 68°F “harm threshold” for adult and juvenile fish. Salmon and steelhead begin to suffer harmful effects when water temperatures exceed 68° Fahrenheit. The longer temperatures remain above 68°F and the higher the temperatures rise above 68°F, the more severe the potential effects, including: increased metabolism, increased susceptibility to disease, reduced reproductive potential, and/or death (see Issue 1 for more detailed information).

Discussion: Since April, temperatures in the lower Snake River and the lower Columbia River reservoirs have steadily moved upward. During April and May, trends have tracked closely with the 10-year average. In June, however, water temperatures dropped considerably below this average. This was good for cold-water species like salmon and steelhead, but since July, temperatures have reached and exceeded the 68°F “harm threshold” in the reservoirs on the lower Snake and Columbia River. Below, we present the highest temperatures for each reservoir on the lower Snake and Columbia River.

A note on data information: The mean water temperature data from these reports comes from the USGS Current Conditions for Washington State and the 10-year average water temperature data comes from the Fish Passage Center. There is no available data for Lower Monumental 10-year average water temperature. Graphs and tables were assembled by SOS Staff.

 III. WEEKLY HIGH TEMPERATURES: 8/30 - 9/5*

Harmful water temperatures in the lower Snake River reservoirs: This week, all reservoirs exceeded 68 degrees. The Little Goose Dam reservoir has spent 48 days above 68°F and similarly, the Ice Harbor Dam spent 46 consecutive days above 68°F.

The reservoir behind the Lower Granite registered the highest temperature at 71.96°F on August 31st - significantly above the level that cold-water fish require. The waters behind the Ice Harbor Dam registered the second highest temperature at 71.24°F.

* NOTE re: this week’s lower Snake River water temperatures: USGS Washington State has ended its daily recordings of lower Snake River water temperatures for 2022. However, considering the conditions we see in the lower Columbia Rivers (temperatures below), we know salmon are migrating through lethal conditions and temperatures. Next week, we’ll explore the highest recorded temperature for each reservoir during this summer.

This week, on the lower Columbia River, all reservoirs peaked over 68°F. The reservoirs behind the John Day Dam registered the highest temperature: 73.04°F.

 IV. Interview with Dr. Deborah Giles - Science and Research Director at Wild Orca

Critically endangered Southern Resident Orcas need more chinook salmon: This week, we have a special addition to the Hot Water Report - an interview with Dr. Deborah Giles, one of the world’s leading experts on Southern Resident orcas. Dr.Giles is the Science and Research Director at Wild Orca - a non-profit organization - and SOS member organization - based in Washington State.

Highly social, highly intelligent Southern Resident killer whales have roamed the coastal waters of the Pacific Northwest for hundreds of thousands of years – relying primarily on an abundance of large, fatty Chinook salmon for their diet. However, Southern Resident orcas face extinction today due to the steep declines of Chinook salmon populations across the Pacific Northwest. Only 73 individual orcas survive today.

Dr. Giles and other scientists agree there is an urgent need to remove the four lower Snake River dams to restore Snake River salmon runs, restore salmon habitats across the PNW, and protect marine habitats in order to increase their ability to reproduce, and increase their survival rate. Dr. Giles’ interview provides an in-depth look at the status of Southern Resident orcas, as well as actions our region should take to protect and restore both salmon and orcas.

 1. Dr. Giles, can you tell us a little bit about you and your work with Southern Resident orcas?

I've been researching Southern Residents professionally since 2005. I started my Masters in 2006 and finished up with my Masters and PhD in 2007 and 2014. All of that study was focused on the Southern Resident killer whales.

I started working for the Scat project (at the UW) in 2009, and have continued this work (Health Monitoring Program) under Wild Orca. We use a scat detection dog (Eba) on the front of the boat to sniff out killer whale feces. We collect the fecal samples and analyze them for stress hormones, nutrition hormones, pregnancy hormones, and toxicants in the environment – basically man-made chemicals making their way up the food chain and into the blubber of the whales. We're also now looking at other threats such as Harmful Algal Bloom impacts and other forms of toxins that are released into the food web, and we're partnering with DFO (Fisheries and Oceans Canada) on that right now. Also, we can look at parasites, fungus, bacteria – pretty much anything you can imagine that can be looked at from a blubber biopsy or blood sample, we can determine from a fecal sample. And what's nice about the way that we do this is that we're far away from the whale so we non-invasively are able to collect these samples. Using Eba allows us to stay really far away from the backend of the animal.

2. Why are Snake River salmon important to Southern Resident orcas?

The Snake River would have contributed as much as 50% of the salmon that existed in the Columbia Basin, historically. And going back in time, there's no doubt that the Southern Resident killer whales co-evolved eating Pacific salmon, and specifically, the really, really large salmon that would have spawned in the Snake River. Even with the low abundance of Snake River salmon, we do see that the whales are targeting those fish and so in a nutshell, Snake River salmon would have been food that the whales would have eaten as tribes say – since time immemorial most likely. And the fact that there are so few of them now is impacting the whales overall health as a population. 

3. What is the connection between orcas and restoring the lower Snake River? Why is this region significant to Southern Resident orcas?

The Snake River is highly modified, it's been damaged by humans in many, many different ways. The most significant of course, being the installation of the four dams on the lower Snake River. Essentially the dams create a situation in the river system that is not natural. There are large reservoirs that build up behind the dams that create a lot of methane which is a greenhouse gas, which obviously is lending to the climate change issues that we're seeing. The whales need salmon throughout their entire range, throughout the entire year, especially in the winter and early spring when the whales loop around the mouth of the Columbia Basin – a disproportionate amount of time than what would be expected by chance. Most likely those whales have a very deep long history or knowledge of foraging in these waters. These are traditions that are passed down from grandmothers to mothers and mothers to daughters within the Southern Resident killer whale clan. So, these are areas that the whales used to be able to go and get a lot of food and it's just not there now. Having a healthy and restored Snake River means that the salmon, especially the wild stocks of Chinook salmon, can more easily make it out of the river as small smolts and then back to the river, back up past the dams and into an area where they need to spawn. Removing the dams will create a restored habitat which will allow the river to support a higher number of salmon, and in a healthy way.

 4. Can you explain Southern Resident orcas’ family bonds?

So we say that there's one clan, it’s a clan that's connected by acoustics so they essentially speak the same language. Genetically, we now know that they are related to each other. So within the overall umbrella of the Southern Resident killer whale clan, there are three pods: J pod, K pod, and L pod. Of the three pods, J pod has been the most resident of the Resident killer whales in the San Juan Islands and the Southern Canadian Gulf Islands. That being said, K pod and L pod also, historically, used the Salish Sea quite a bit. K pod and L pod are also the two pods that in the fall and winter exit this area and go south, past the Columbia River all the way down to California. K pod ranges as far south as Point Reyes, California, while L pod travels as far as Monterey, California. J pod has never really been seen as far south as the mouth of the Columbia River, which is interesting. But this is a way for the whole community, the whole population to do what's called Habitat Partitioning –splitting up so that they're not in competition with each other for limited prey. And that's what happens during that time of the year (fall, winter, and early spring) – since their prey is just more patchy. It probably always has been, but it's even more so now because of overfishing (the way we manage fisheries – where and when and how we manage offshore fishing), coupled with issues related to the river habitat just not being as conducive to a thriving population of wild Chinook salmon, which is what the whales are co-evolved to be seeking out.

And it's been a challenging few decades for the Southern Residents because we believe that for hundreds of thousands of years, they have been eating salmon along the Pacific coast in abundance, and really what amounts to the blink of an eye, we humans have decimated their prey base and so restoring rivers, whenever possible, and especially large river restoration projects, like the Snake River dam removals, those are going to be the projects that have the best bang for the buck. We're going to be able to increase the amount of salmon available to the Southern Residents considerably once those dams come down.

5. This year, we heard both good and bad news for the Southern Resident orcas. Bad news included, earlier this year, two miscarriages from the J Pod and more recently, K44, an 11-year-old male, has not been seen over the past few months, and unfortunately, it seems that he may have passed away. Why do orcas have a high rate of reproductive loss? How does the death of a family member impact the rest of the orca pod? 

We believe based on fecal sample analysis the biggest cause of the deaths in the Southern Resident population is the lack of prey—that’s mostly Chinook salmon. At different times of the year, Southern Residents’ diet is roughly 90% Chinook salmon, but also other species of salmon like coho and chum. We don't have any evidence to suggest that they ever eat Pink Salmon, but they do occasionally eat some steelhead. They also get small numbers of other fish like rockfish, lingcod, even some skates – one sample showed that they were eating skates, which is an Elasmobranchii in the shark family (it's similar to a stingray). So they do branch out a little bit to other fish species, but they only eat fish. They don't eat any marine mammals, unfortunately, because there's a lot of marine mammals that they could prey on.

The loss of even one member of the population is devastating because there are so few Southern Resident killer whales. We only have probably 73 individuals left. Every single member matters, essentially for different reasons. We know also from our fecal studies, that almost 70% of the females in this population who get pregnant are not able to bring the calf to bear, meaning the calf dies in their uterus and hopefully is miscarried and doesn't kill them in the process, or the baby is born and dies right away. The females that make up the 69.8% who are losing their calves are nutritionally deprived. We know that those are the ones that they're essentially just not getting enough to eat to successfully birth their offspring. These are very clear reasons to say that prey is the biggest problem.

Of course, contaminants in the environment are also a problem, as well as vessels – both the associated noise and just the physical presence of vessels. But out of all three of these main identified threats, the lack of prey is by far the biggest because when they're not getting enough to eat, they're more susceptible to metabolizing their fat stores (releasing those toxicants or those chemicals from their fat stores), which circulates through their body making them immune compromised. It makes it harder to forage – imagine if you were starving and metabolizing your fat stores was releasing toxicants into your system. This is happening with the whales, but on a regular basis. They're often in some stage of starvation. So back to the question about why one death matters, it's really just a numbers game and you know, it can be thought of as simply as that. Every member is a vital member of the population and when we lose one of them, it's just ratcheting down with the population number more and more and more.

 6. What can Members of Congress, policymakers, salmon and orca advocates, and citizens do to help orcas now?

The most important thing to do is to really be looking at this as a full picture. It's not just one thing that needs to happen. We need to remove dams like the four Snake River dams. We need to continue to look at other river systems that would have produced salmon in the past and look to find ways to recover those rivers.Restoring the habitat in areas where the river system is fairly pristine to protect it in a way so that it can't be degraded. We need to be looking at harvest as well, when and where and how we're fishing for salmon. We have to have a better idea of the salmon that is being caught in other fisheries, that end up yielding a lot of what's called bycatch–accidentally caught Chinook salmon in other fisheries–that’s a big problem. And then, being more aware of how we're treating the environment in all aspects. Making sure that we're not putting toxiants into the marine realm, which means being careful about how we're managing agriculture because in so many cases, we do not have enough buffer between agricultural lands and rivers/streams, and so everything that happens on the land ends up in the river, which ends up in the ocean, which ultimately means that it ends up in the food web and not only into the whales, but then to humans that are consuming that food as well.

The decline of salmon is a big problem for tribes, who rely on fish or other species in the marine realm for not only their food, their protein but also for their ceremonies. And it's important for us to be mindful of that and recover these salmon, for the salmon sake, for the human sake–humans that rely on the salmon– and of course, for the Southern Resident killer whales, who have lived in these waters and have been eating Pacific salmon for hundreds of thousands of years.

 LINKS TO RECENT NEWS AND INFORMATION:

• The New York Times: Breaching Dams 'Must Be an Option' to Save Salmon, Washington Democrats Say (August 31, 2022) 
• Past Hot Water Reports are archived here: Hot Water Reports - Compiled

Martha Campos is the Hot Water Report Coordinator with Save Our wild Salmon this summer while she resides on Kizh/Tongva ancestral lands in California. Martha holds a BA from the University of California, Davis in Native American Studies (and two minors: Environmental Policy, Analysis, and Planning and Climate Science and Policy) and is a queer, nonbinary person of color with ancestral roots in Mexico.

Sockeye salmon with lesions dying from hot water in the Columbia-Snake River Basin ©Conrad Gowell

I. INTRODUCTION

Welcome to the 2023 Hot Water Report: Warming Waters in the Lower Snake and Columbia Rivers.

During the summer, this weekly report provides an update on real-time water temperatures in the lower Snake and Columbia River reservoirs via graphs and analyses, a summary of the highest weekly water temperatures at the forebay/reservoir of each federal dam, and a monthly status of adult returns for different salmon and steelhead populations as they make their way back to their natal spawning grounds. We’ll report first-hand from scientists, Tribal members, fishing guides, advocates, and other experts about the challenges facing these rivers – and our opportunities to improve and restore them - in order to recover healthy, resilient fish populations and the benefits they deliver to Northwest communities, other fish and wildlife populations (including the critically endangered Southern Resident orca), and ecosystems.

Many once-abundant anadromous fish populations—fish that hatch in freshwater, go to sea, and return to freshwater to spawn—in the Columbia-Snake River Basin are on the brink of extinction today due primarily to harms caused by federal dams and their warming reservoirs. The Columbia-Snake federal hydro-system harms and kills both juvenile and adult fish in multiple ways, including by elevating water temperatures in the summer months in their large, stagnant reservoirs. These cold-water fish begin to suffer harmful effects when water temperatures exceed 68° Fahrenheit.

This week, on the lower Snake River, the reservoir behind the Ice Harbor Dam registered the highest water temperature at 71.64°F on August 12. On the lower Columbia River, the Bonneville and the John Day reservoirs registered the highest water temperature at 73.40°F, this week. Salmon and steelhead entering the lower Columbia River are now facing temperatures at 73°F—5 degrees above the 68°F “harm” threshold. For Issue 7, we have a special addition to the Hot Water Report - a series of articles about Southern Resident orcas and the urgency to restore the lower Snake River through dam removal to bring salmon back to abundance and significantly increase the amount of salmon available to the Southern Residents.

Restoring the lower Snake River by removing the four federal dams and replacing their services, is our only opportunity to recover and protect these once-highly prolific salmon and steelhead populations from extinction, uphold our nation's promises to Tribes, and help feed the critically endangered Southern Residents.

View the past Hot Water Report issues here: Hot Water Reports - Compiled

The Hot Water Report is a joint project of the Save Our wild Salmon Coalition, American Rivers, Association of Northwest Steelheaders, Columbia Riverkeeper, Earthjustice, Endangered Species Coalition, Environment Oregon, Idaho Conservation League, Idaho Rivers United, Natural Resources Defense Council, National Wildlife Federation, Northwest Sportfishing Industry Association, Orca Network, Sierra Club, Snake River Waterkeeper, Wild Orca and Wild Steelhead Coalition.

 II. READING THE DATA - Water Temperatures in the Lower Snake and Columbia Rivers

Figure 1. Lower Snake River Water Temperatures - 2023 Daily Average and 10-year Average. Click on the image to view the graph.

Introduction to the data:
The daily average temperature at the four reservoir forebays (measured with sensors stationed at various depths below the reservoir surface, immediately upstream from the dam) in the lower Snake River (above) and the lower Columbia River (below) for 2023 is represented with solid lines and the 10-year average (2013 - 2023) temperatures with dashed lines of the same color. The dotted line across the graph represents the 68°F “harm threshold” for adult and juvenile fish.

The longer and the higher these temperatures rise above 68°F, the greater the harm, including: migration disruption, increased metabolism, increased susceptibility to disease, reduced reproductive potential (by reducing egg viability), suffocation (warm water carries less dissolved oxygen), and in the worst case - death.

Reservoirs are large, stagnant pools that absorb enormous amounts of solar radiation, and cause the water to warm. These waters inundate and destroy diverse micro-habitats that healthy rivers support, including cold-water refuges that salmon and steelhead rely upon during their migration. Without these vital pockets of cold water, salmonids cannot rest and recover on their journeys—adults moving upstream to spawn and juveniles moving downstream to the ocean. Rising temperatures and reductions in snowpack in recent decades due to climate change create warmer waters, which results in lower survival and reduced reproductive success for salmon and steelhead.

Figure 2. Lower Columbia River Water Temperatures - 2023 Daily Average and 10-year Average. Click on the image to view the graph.

Discussion of data:
Since April, temperatures in the lower Snake River and the lower Columbia River reservoirs have steadily increased. As Figure 1 shows, this week, the reservoir behind the Ice Harbor Dam had the highest average temperature of 71.40°F from August 12. The Lower Monumental reservoir had the second highest average temperature of 70.44°F on August 17.

As Figure 2 shows, this week, the reservoir behind the Bonneville dam registered the highest average temperature of 73.22°F on August 16 and 17. Both juvenile and adult salmon continue to experience water temperatures well above the 68°F “harm” threshold for over 40 days.

Below, we present the weekly high water temperatures for each reservoir on the lower Snake and Columbia rivers for August 9 - August 17. 

A note on the data: The 2023 lower Snake River and lower Columbia River water temperature data presented in the Hot Water Report are collected from the Columbia River DART program by Columbia Basin Research, University of Washington, using data courtesy of the U.S. Army Corps of Engineers (USACE). The 10-year average water temperature data is courtesy of the Fish Passage Center. There is no data available for the Lower Monumental 10-year average water temperature, and McNary reservoir water temperature data is collected from USACE with current available data. Graphs and tables were assembled by SOS Staff.

III. WEEKLY HIGH WATER TEMPERATURES: August 9 - August 17

This week, on the lower Snake River, the reservoir behind the Ice Harbor Dam registered the highest water temperature at 71.64°F on August 12, and the Little Goose Dam registered the second highest temperature at 70.92°F on August 17.
This week, on the lower Columbia River, the Bonneville reservoir registered the highest water temperature at 73.58°F.

IV. Critically endangered Southern Resident orcas need more Chinook salmon

K17 (large dorsal fin) with family at sunset ©Center for Whale Research

Highly social, highly intelligent Southern Resident orcas have roamed the coastal waters of the Pacific Northwest for hundreds of thousands of years. The three Southern Resident orca populations - the J, K, and L pods - have historically fed on an abundance of large, fatty Chinook salmon. However, today, Southern Residents face extinction due to the steep declines of Chinook salmon populations across the Pacific Northwest.

This week, we have a special addition to the Hot Water Report— a series of articles about Southern Resident orcas and the urgency to restore the lower Snake River through dam removal to bring salmon back to abundance and significantly increase the amount of salmon available to the Southern Residents, especially in the winter months when other salmon populations are far less available.

A. ‘Salmon and Orcas Are Being Managed Toward Extinction—and So Is the Lummi Nation’

By W’tot lhem (Jay Julius)

J,K, and L pods returning to the Salish Sea in early June, 2008 ©Erin Heydenreich

“Like other members of the Lummi Nation, I am often out on these waters in the company of our ancestors and with our elders such as scha’enexw (“the salmon”), qwe’lhol mechen (“the killer whales”), and all our other relations in Xw’ullemy (the Salish Sea).

We call these other forms of life our elders because they are the ones who came first. We humans were the young and weak ones who could not survive without their generosity, their pity and compassion, and their spiritual strength. I sometimes wonder what qwe’lhol mechen would say if they could speak about their two-legged relatives on the land. I believe they would ask us if we know we are destroying their home and their way of life, and also starving their families and driving them to extinction. I believe they would ask why we have forgotten an inviolable and sacred obligation we made to them long ago.

We appeal, once again, to state and federal politicians to honor the spirit and intent of the treaties by breaching the Lower Snake River dams. We call on those officials to stand on the right side of history and on the moral high ground. They know and understand this is a matter of the survival of our lifeway and the spirit of our people.”

Read the full article here.

W’tot lhem (Jay Julius) is former Chairman of the Lummi Nation, a full-time fisher and father, and the Founder and President of Se’Se’Le.

B. Endangered orcas’ risk of inbreeding is increased by insufficient Chinook salmon and lack of positive government action to save both predator and prey.

ByWild Orca

L127 with mother, L94 | Taken under NMFS permit #26288 | Wild Orca.

Current Status
The total population of the Southern Residents now stands at 75, with the recent addition of two new calves. A male calf, L126, was born to Joy (L119), an eleven-year-old. Also, in L pod, a female calf, L127, was born to 28-year-old Calypso (L94).

This is welcome and good news. But while we celebrate these births that give us hope for the population, we must also keep in mind that the population, as a whole, is still struggling and urgent conservation actions are needed now more than ever. 11 of the Southern Residents are listed as vulnerable by Washington State Department of Fish and Wildlife (WDFW). Six of these whales remain on the list from last year. According to WDFW’s emergency rule, “the orca’s body condition falls in the lowest 20% of measurements for their age and sex compared to comparable measurements from 2016-2023.

Threats to recovery
Southern Residents are the original fishers of the PNW waters, co-evolving over millennia with their preferred prey, Chinook salmon. We know that almost half of the Southern Resident’s salmon originate in the Columbia River Basin. Before the lower Snake River dams were built in the 1960s and ‘70s, 40% of Chinook salmon began life in the Snake River Basin. Until roughly 100 years ago, Southern Resident orcas’ historical numbers ranged from 100 – 250 members. In this brief spate of time, colonizers arriving in the Pacific Northwest have drastically altered orcas and salmon’s habitat and population numbers by damming rivers, overfishing, deforestation, polluting waterways, and excessive, artificial noise such as marine vessels, aircraft, and other anthropogenic disturbances.

Another known threat that has recently been the subject of a 2023 study by NOAA is inbreeding. Southern Resident killer whales’ small population size puts them at risk of inbreeding. Coast-wide salmon declines initially caused a steep population decline in the Southern Residents, impacting their genetic diversity. In addition, it is now uncommon for true superpods to occur due to lack of salmon abundance. Simply put, there is not enough salmon to support the entire Southern Resident community in one place at one time. This decreases mating opportunities across the population and further impacts the gene pool. This risk is significantly increased by the lack of government action urgently needed to prevent the extinction of wild Chinook salmon. Well-fed whales would be less susceptible to disease and the impacts of environmental pollutants and vessels.

NOAA’s study, Inbreeding depression explains killer whale population dynamics, assesses how often inbreeding—mating with an animal with a common ancestor—occurs in the Southern Resident killer whale population. Scientists believe this leads to lower survival rates and population decline, known as “inbreeding depression.” Could this be a critical factor in their current struggle for survival, as NOAA now claims, or could their small population size and ill-health result from decades of inaction to restore wild Chinook salmon?

Is inbreeding the reason the SRKWs are not recovering?

Read the full article here.

C. Lasting Legacies of the Southern Resident orcas

J59 Sxwyeqόlh, female, born 2022 ©Cindy Hansen

The Southern Residents are one of the most studied and well-known populations of whales anywhere in the world. Thanks to pioneering research by Michael Bigg and Ken Balcomb, every orca in the population can be identified by unique markings and observed throughout their lives. Ongoing work by the Center for Whale Research provides known or estimated ages for each individual and an entire family tree dating back to 1976. We know who is a grandmother, an uncle, a cousin, or a friend. We know they share their prey with one another, even when times are hard and salmon is hard to come by. Because of this incredible body of work, people around the world have come to know and love these whales as individuals with unique personalities. During Orca Action Month every June, the Orca Salmon Allianceand their partners share stories so the public can get to know some legendary Southern Resident orcas who have left behind a ‘Lasting Legacy.’

Read more here.

People from all walks of life are united over their love and admiration for Southern Resident orcas, and no one wants to see them go extinct. If we want them to recover and thrive once again in the Pacific Northwest waters that have been their home for countless generations, we have to focus on recovering their prey.

One of the most essential components of a comprehensive range-wide recovery plan is restoring the Columbia-Snake River Chinook that are listed as a priority stock and make up the bulk of coastal diet for the Southern Residents. We need to immediately begin to replace the services provided by the Snake River dams, and begin breaching the dams as soon as possible. It doesn't have to be an us vs them situation - we can help recover endangered Snake River salmon, and in turn the Southern Resident orcas, while also ensuring our state continues to work toward alternatives for those whose livelihoods will be impacted by the breaching of the dams.

– Orca Network 

 

Sockeye salmon with lesions dying from hot water in the Columbia-Snake River Basin ©Conrad Gowell

I. INTRODUCTION

Welcome to the 2023 Hot Water Report: Warming Waters in the Lower Snake and Columbia Rivers.

During the summer, this weekly report provides an update on real-time water temperatures in the lower Snake and Columbia River reservoirs via graphs and analyses, a summary of the highest weekly water temperatures at the forebay/reservoir of each federal dam, and a monthly status of adult returns for different salmon and steelhead populations as they make their way back to their natal spawning grounds. We’ll report first-hand from scientists, Tribal members, fishing guides, advocates, and other experts about the challenges facing these rivers – and our opportunities to improve and restore them - in order to recover healthy, resilient fish populations and the benefits they deliver to Northwest communities, other fish and wildlife populations (including the critically endangered Southern Resident orca), and ecosystems.

Many once-abundant anadromous fish populations—fish that hatch in freshwater, go to sea, and return to freshwater to spawn—in the Columbia-Snake River Basin are on the brink of extinction today due primarily to harms caused by federal dams and their warming reservoirs. The Columbia-Snake federal hydro-system harms and kills both juvenile and adult fish in multiple ways, including by elevating water temperatures in the summer months in their large, stagnant reservoirs. These cold-water fish begin to suffer harmful effects when water temperatures exceed 68° Fahrenheit.

This week, on the lower Snake River, the reservoir behind the Ice Harbor Dam registered the highest water temperature at 72.73°F on August 19. This week, on the lower Columbia River, the John Day reservoirs registered the highest water temperature at 73.40°F. Salmon and steelhead entering the lower Columbia River are facing temperatures at 73°F—5 degrees above the 68°F “harm” threshold. In Issue 8, we’re addressing how the lower Snake River dams’ impact Snake River salmon and steelhead and their freshwater ecosystems. There is a misleading narrative that warming ocean conditions are the real obstacle to recovering healthy, abundant populations of Snake River salmon and steelhead. Yet, Snake River salmon and steelhead suffer the highest mortality rates, and lowest smolt-to-adult return ratios, compared to other fish that spawn lower in the watershed and encounter fewer dams and reservoirs. This issue reports the current estimated status of Snake River salmon and steelhead returns as of August 17, 2023.

Restoring a free-flowing Snake River by removing its four dams and replacing their services is essential to provide cold, clean, healthy water for salmon and steelhead, recover and protect these once-highly prolific fish populations from extinction, uphold our nation's promises to Tribes, and help feed the critically endangered Southern Residents.

View the past Hot Water Report issues here: Hot Water Reports - Compiled

The Hot Water Report is a joint project of the Save Our wild Salmon Coalition, American Rivers, Association of Northwest Steelheaders, Columbia Riverkeeper, Earthjustice, Endangered Species Coalition, Environment Oregon, Idaho Conservation League, Idaho Rivers United, Natural Resources Defense Council, National Wildlife Federation, Northwest Sportfishing Industry Association, Orca Network, Sierra Club, Snake River Waterkeeper, Wild Orca and Wild Steelhead Coalition.

II. READING THE DATA - Water Temperatures in the Lower Snake and Columbia Rivers

Figure 1. Lower Snake River Water Temperatures - 2023 Daily Average and 10-year Average. Click on the image to view the graph.

Introduction to the data:
The daily average temperature at the four reservoir forebays (measured with sensors stationed at various depths below the reservoir surface, immediately upstream from the dam) in the lower Snake River (above) and the lower Columbia River (below) for 2023 is represented with solid lines and the 10-year average (2013 - 2023) temperatures with dashed lines of the same color. The dotted line across the graph represents the 68°F “harm threshold” for adult and juvenile fish.

The longer and the higher these temperatures rise above 68°F, the greater the harm, including: migration disruption, increased metabolism, increased susceptibility to disease, reduced reproductive potential (by reducing egg viability), suffocation (warm water carries less dissolved oxygen), and in the worst case - death. 

Figure 2. Lower Columbia River Water Temperatures - 2023 Daily Average and 10-year Average. Click on the image to view the graph.

Discussion of data:
Since April, temperatures in the lower Snake River and the lower Columbia River reservoirs have steadily increased. As Figure 1 shows, the reservoir behind the Ice Harbor Dam had the highest average temperature of 71.83°F on August 19. The Lower Monumental reservoir had the second highest average temperature of 71.52°F on August 14.

As Figure 2 shows, the reservoir behind the John Day Dam registered the highest average temperature of 72.86°F on August 20. Both juvenile and adult salmon continue to experience water temperatures well above the 68°F “harm” threshold for over 50 days.

Below, we present the weekly high water temperatures for each reservoir on the lower Snake and Columbia rivers for August 18 - August 23.

A note on the data: The 2023 lower Snake River and lower Columbia River water temperature data presented in the Hot Water Report are collected from the Columbia River DART program by Columbia Basin Research, University of Washington, using data courtesy of the U.S. Army Corps of Engineers (USACE). The 10-year average water temperature data is courtesy of the Fish Passage Center. There is no data available for the Lower Monumental 10-year average water temperature, and McNary reservoir water temperature data is collected from USACE with current available data. Graphs and tables were assembled by SOS Staff.

III. WEEKLY HIGH WATER TEMPERATURES: August 18 - August 23

This week, on the lower Snake River, the reservoir behind the Ice Harbor Dam registered the highest water temperature at 72.73°F on August 19, and the Lower Monumental Dam registered the second highest temperature at 71.71°F on August 20. 

This week, on the lower Columbia River, the John Day reservoirs registered the highest water temperature at 73.40°F.

IV. Restoring a healthy lower Snake River for salmon and steelhead

Northwest salmon and steelhead all swim in the same ocean; however, their mortality rates increase significantly with the number of dams and reservoirs they encounter. Endangered Snake River salmon and steelhead must traverse eight stagnant reservoirs created by federal dams on their migration to the ocean and again on their journey back upstream as adults. There is a misleading narrative advanced by defenders of the status quo that warming ocean conditions are the real obstacle to recovering healthy, abundant populations of Snake River salmon and steelhead. Yet, Snake River salmon and steelhead suffer the highest mortality rates, and lowest smolt-to-adult return ratios, compared to other fish that spawn lower in the watershed and encounter fewer dams and reservoirs.

Salmon and their ecosystems:

Freshwater: Salmon and steelhead require clean, cold water, intact/contiguous rivers, and reliable streamflows for spawning, rearing, and migration. Before the dams were built, juvenile salmon were able to migrate quickly to the ocean - within a few days to several weeks - due to the swiftly moving current of the Snake and Columbia rivers. Now, because of the harmful conditions created by the lower Snake River dams and their hot reservoirs, it takes salmon and steelhead on average more than a month to reach the ocean. According to scientists, Snake River fish that successfully reach the ocean, often arrive injured, stressed, and weak, leading to 'delayed mortality' in the estuary and the ocean. The fish that do survive will range in the ocean for one to six years. Adult salmon then return to freshwater to spawn, and die, in the same rivers or streams where they were born. Steelhead are a little different; they have the ability to return to the ocean after they spawn and repeat this process one or more times–albeit this capacity has diminished due the number of dams and reservoirs they encounter on their journey.

Saltwater: The ocean has a long-running and well-documented cyclic pattern of good conditions followed by bad conditions. Ocean conditions play a significant role in salmon and steelhead survival. When ocean conditions are good (abundant food availability for salmon and steelhead to eat), salmonid survival in the ocean increases, and we see increased survival of juvenile fish as they enter the ocean and increased adult salmon returns back into the Columbia-Snake Basin. When ocean conditions decline (reduced food availability), we often see adult returns decline too.

“Scientific studies continue to show that breaching the four lower Snake River dams would provide greater certainty of achieving long-term survival and recovery of native wild fishes more than any other measure or combination of measures without dam breaching.

Breaching the dams to restore riverine habitats in the lower Snake River will also benefit ecosystem processes, entire biological communities, and increase climate change resilience of anadromous fishes.” –The American Fisheries Society (AFS) and The Western Division AFS

The lower Snake River dams' impact on freshwater habitat and salmon:

This summer, the Northwest is experiencing ocean heat waves amplified by climate change and El Niño. While addressing ocean conditions must be a priority now and over time, there are necessary and meaningful actions we can - and must - take today in freshwater ecosystems to protect our region’s emblematic Snake River fish from extinction and to restore them to abundance. Like many other parts of the country this summer, the Northwest is experiencing land and river heat waves. Due to early snowmelt, a lack of spring rain and warmer spring, and low streamflows, the Washington Department of Ecology declared a drought emergency on July 24, for multiple counties located in the lower Snake River Basin.

Dams increase water temperatures in the lower Snake River reservoirs to lethal levels. They absorb solar radiation and destroy diverse microhabitats within healthy rivers, including cold-water refuges for migratory fish. During summer nights, there is little opportunity for reservoirs to cool. Restoring a free-flowing Snake River by removing its four dams is essential for preventing salmon extinction.

In the Columbia-Snake Basin, the construction of the federal hydro system has profoundly degraded viable fish habitat. The four lower Snake River dams are an undeniably large source of mortality for salmon and steelhead.

“The basin’s native salmon and steelhead hover on the brink of extinction. Today, only 1-2% of historic wild salmon and steelhead return to the Snake River to spawn above the four lower Snake River dams. Climate change will continue to worsen the outlook for these coldwater species.

Ensuring access to this high-elevation habitat is the best opportunity to promote broad-scale population recovery in the face of warming waters.” –Doug Austen, Executive Director of American Fisheries Society and Helen Neville, Senior Scientist at Trout Unlimited

How do we know the lower Snake River dams are a large source of mortality for Snake River fish?

Sockeye salmon with lesions dying from hot water in the Columbia-Snake River Basin ©Conrad Gowell

We use the smolt-to-adult ratio - or SAR - to see the percentage of ocean-bound juvenile fish that return as adults to spawn in freshwater.¹ SAR is the only metric that captures the cumulative impacts of the hydro-system on salmon and steelhead and thus indicates the sustainability of adult returns. In order to maintain current population levels, Snake River salmon must return consistently at a 2 percent SAR (meaning, for every 100 smolts that head out to the ocean, 2 adults must successfully return to spawn). Rebuilding abundant, harvestable Snake River salmon and steelhead populations will require SARs between 4 and 6 percent (for every 100 smolts that head out to the ocean, 4 to 6 adults must successfully return to spawn).

After the completion of the lower Snake River dams in 1975, SARs for Snake River Chinook salmon have fallen consistently below 1 percent and steelhead SARs average just over 1%. This decline in SARs below 1% represents a trajectory toward extinction as not enough smolts survive to maintain healthy population numbers over time.

Smolt-to-Adult Ratios (SARs) decrease as the number of dams and reservoirs fish encounter increase:

• Fish encountering 2 - 3 dams: Almost 7% of steelhead smolts from Oregon’s Deschutes River, who pass just two dams going and coming, successfully return as adults. More than 5% of Steelhead smolts from the John Day River, (three dams) return as adults, as do about 3.6% of Chinook smolts.
• Fish encountering 4 dams: On the Yakima River, about 4.5% of steelhead smolts return to spawn, as do a little over 2.7% of Chinook.
• Fish encountering 8 dams: Snake River salmon and steelhead encounter 8 dams and reservoirs - twice, in each direction - to successfully return as adults. On average, just 1.6% of these steelhead smolts return as adults and only 0.76% of Chinook pass the Lower Granite Dam and complete the journey.

The evidence is clear – the more dams that anadromous fish populations must navigate, the lower the smolt-to-adult return ratio.

“The SARs tell the story that matters: passage through four dams or fewer allows SARs that equal maintaining and rebuilding salmon populations. Passage through eight dams yields SARs that point to imminent extinction. Clearly, the fewer dams and the more juvenile salmon we can get to the ocean in good condition, the better chance we have of getting more adults back to their spawning grounds regardless of ocean conditions.” –Rick Williams, Fisheries ecologist and Research Associate in the Department of Biology at The College of Idaho.

Restoring the lower Snake River and its fish:

Through modeling, scientists compared Spring Chinook returns with the dams in place and with removal of the lower Snake River dams under three ocean conditions: bad, average, and good.² With dam removal, Spring Chinook returns increased in abundance and above healthy and harvestable recovery goals under each ocean condition.

As ocean conditions continue to decline in the face of climate change, it is critical that now, more than ever, we focus our efforts on near-term, tangible solutions that will increase and improve salmon survival in freshwater habitat. We may not be able to control the cyclical ocean conditions that salmon encounter, but we can restore health to the rivers they journey through on their way to and from the ocean. The science is clear: restoring the Snake River by removing the four lower Snake River dams is an essential action we must take as quickly as possible, or we will lose its wild salmon and steelhead populations forever.

References:
1. Trout Unlimited, What is a smolt-to-adult ratio and why is it important?
2. NMFS (National Marine Fisheries Service), 2020. A vision for salmon and steelhead: goals to restore thriving salmon and steelhead to the Columbia River basin. Phase 2 report of the Columbia River Partnership Task Force of the Marine Fisheries Advisory Committee. Portland, OR

V. Current Status of Snake River Returns as of 8/17/23

“As we consider the future of our Northwest salmon and the communities that rely on it, we must make decisions grounded in scientific evidence. As returns continue to decline, decision-makers at all levels must take swift and decisive action to breach the lower four Snake River dams.” –Doug Austen, Executive Director of American Fisheries Society and Helen Neville, Senior Scientist at Trout Unlimited

Below are the current estimated returns of native Snake River fish so far, including (1) wild Snake River Spring/Summer Chinook, (2) wild steelhead, and (3) wild/natural sockeye. Over the past several decades, these fish have returned annually far below the recovery goals necessary to remove them from the protections of the Endangered Species Act. Without immediate and meaningful conservation actions, scientists predict these populations will continue to decline toward extinction.

• Endangered Species Act Status: Threatened (listed in 1992)
• Historical Annual Return: Over 2 million
• Recovery Goal: Escapement of 127,000 wild adults per year
• 2023 Estimated Wild Returns as of August 17: 10,714

• Endangered Species Act Status: Threatened (listed in 1997)
• Historical Annual Return: Over 1 million
• Recovery Goal: Escapement of 104,500 wild adults per year
• 2022/2023 Estimated Wild Returns as of August 17: 19,138

• Endangered Species Act Status: Endangered (listed in 1991)
• Historical Annual Return: Over 100,000+/yr to central Idaho’s high mountain lakes
• Recovery Goal: 9,000 wild adults per year to the Stanley Basin
• 2023 Estimated Wild Returns as of August 17: 12 wild/natural-origin sockeye

A note on the ‘Snake River Wild Salmon Returns’ report: The data from this report comes from the Fish Passage Center and Idaho Department of Fish and Game. Tables and graphs were assembled by Idaho Rivers United staff.

Sockeye salmon with lesions dying from hot water in the Columbia-Snake River Basin ©Conrad Gowell

I. INTRODUCTION

Welcome to the 2023 Hot Water Report: Warming Waters in the Lower Snake and Columbia Rivers.

During the summer, this weekly report provides an update on real-time water temperatures in the lower Snake and Columbia River reservoirs via graphs and analyses, a summary of the highest weekly water temperatures at the forebay/reservoir of each federal dam, and a monthly status of adult returns for different salmon and steelhead populations as they make their way back to their natal spawning grounds. We’ll report first-hand from scientists, Tribal members, fishing guides, advocates, and other experts about the challenges facing these rivers – and our opportunities to improve and restore them - in order to recover healthy, resilient fish populations and the benefits they deliver to Northwest communities, other fish and wildlife populations (including the critically endangered Southern Resident orca), and ecosystems.

Many once-abundant anadromous fish populations - fish that hatch in freshwater, go to sea, and return to freshwater to spawn - in the Columbia-Snake River Basin are on the brink of extinction today due primarily to harms caused by federal dams and their warming reservoirs. The Columbia-Snake federal hydro-system harms and kills both juvenile and adult fish in multiple ways, including by elevating water temperatures in the summer months in their large, stagnant reservoirs. These cold-water fish begin to suffer harmful effects when water temperatures exceed 68° Fahrenheit.

This week, on the lower Snake River, the reservoir behind the Ice Harbor Dam registered the highest water temperature at 72.50°F on July 26 – over 4 degrees over the 68°F “harm” threshold. This week marks the second week, where the lower Snake River reached 72 degrees, a temperature that can stop salmon from migrating. In Issue 5, we’ll provide insight into how steep salmon declines in the lower Snake River dams and elsewhere in the Columbia Basin have impacted commercial salmon fisheries. The restoration of Snake River salmon by removing the four lower Snake River dams will, among many other benefits, expand economic opportunity for commercial salmon fisheries in the ocean and in Columbia-Snake River Basin by rebuilding runs of the salmon and steelhead, which Northwest Tribal, sport, and commercial fishing depend on.

Importantly, a restored, healthy, and resilient lower Snake River is necessary to uphold our nation's promises to Tribes and sustain salmon populations in perpetuity. Lower Snake River dam removal is our greatest salmon restoration opportunity on the West Coast today; it will reconnect the Northwest’s most emblematic fish to over 5,500 miles of pristine, cold-water river and streams in Idaho, Oregon, and Washington.

The Hot Water Report is a joint project of the Save Our wild Salmon Coalition, American Rivers, Association of Northwest Steelheaders, Columbia Riverkeeper, Earthjustice, Endangered Species Coalition, Environment Oregon, Idaho Conservation League, Idaho Rivers United, Natural Resources Defense Council, National Wildlife Federation, Northwest Sportfishing Industry Association, Orca Network, Sierra Club, Snake River Waterkeeper, Wild Orca and Wild Steelhead Coalition.

II. READING THE DATA - Water Temperatures in the Lower Snake and Columbia Rivers

Figure 1. Lower Snake River Water Temperatures - 2023 Daily Average and 10-year Average. Click on the image to view the graph.

Introduction to the data:
The daily average temperature at the four reservoir forebays (measured with sensors stationed at various depths below the reservoir surface, immediately upstream from the dam) in the lower Snake River (above) and the lower Columbia River (below) for 2023 is represented with solid lines and the 10-year average (2013 - 2023) temperatures with dashed lines of the same color. The dotted line across the graph represents the 68°F “harm threshold” for adult and juvenile fish.

The longer and the higher these temperatures rise above 68°F, the greater the harm, including: migration disruption, increased metabolism, increased susceptibility to disease, reduced reproductive potential (by reducing egg viability), suffocation (warm water carries less dissolved oxygen), and in the worst case - death.

Reservoirs are large, stagnant pools that absorb enormous amounts of solar radiation, and cause the water to warm. These waters inundate and destroy diverse micro-habitats that healthy rivers support, including cold-water refuges that salmon and steelhead rely upon during their migration. Without these vital pockets of cold water, salmonids cannot rest and recover on their journeys – adults moving upstream to spawn and juveniles moving downstream to the ocean. Rising temperatures and reductions in snowpack in recent decades due to climate change create warmer waters, which results in lower survival and reduced reproductive success for salmon and steelhead.

Figure 2. Lower Columbia River Water Temperatures - 2023 Daily Average and 10-year Average. Click on the image to view the graph.

Discussion of data:
Since April, temperatures in the lower Snake River and the lower Columbia River reservoirs have steadily increased. As Figure 1 shows, this week, the reservoir behind the Ice Harbor Dam had the highest average temperature of 72.03°F from July 26. The Lower Monumental reservoir had the second highest average temperature of 70.91°F on August 1.

As Figure 2 shows, this week, the reservoir behind The Dalles Dam, and John Day Dam registered the highest average temperature of 72.14°F. Both juvenile and adult salmon are experiencing water temperatures above the 68°F “harm” threshold in several of the reservoirs they pass.

Below, we present the weekly high water temperatures for each reservoir on the lower Snake and Columbia rivers for July 26 - August 2. 

A note on the data: The 2023 lower Snake River and lower Columbia River water temperature data presented in the Hot Water Report are collected from the Columbia River DART program by Columbia Basin Research, University of Washington, using data courtesy of the U.S. Army Corps of Engineers (USACE). The 10-year average water temperature data is courtesy of the Fish Passage Center. There is no data available for the Lower Monumental 10-year average water temperature, and McNary reservoir water temperature data is collected from USACE with current available data. Graphs and tables were assembled by SOS Staff.

III. WEEKLY HIGH WATER TEMPERATURES: July 26 - August 2 

This week, on the lower Snake River, the reservoir behind the Ice Harbor Dam registered the highest water temperature at 72.50°F on July 26, and the Lower Monumental Dam registered the second highest temperature at 71.26°F on August 1.

This week, on the lower Columbia River, the Dalles Dam reservoir registered the highest water temperature at 72.50°F from July 27 - July 29.

 IV. Salmon declines impacting Northwest Salmon Fishing Opportunity

Columbia-Snake River Basin salmon have historically supported fishing businesses and the related shoreside jobs that are important, long-standing contributors to Washington’s coastal communities and economy. However, with Snake River salmon on the brink of extinction, fishing opportunities in the Columbia and Snake rivers and on the ocean currently are limited in order to protect these imperiled populations. Restoring the lower Snake River by removing the four dams will recover Snake River salmon and steelhead populations and is our greatest opportunity to save and rebuild the declining runs of salmon and steelhead, which many Northwest Tribal, sport, and commercial fishing depend. Additionally, rebuilt salmon populations can once again serve as a critical source of nutrition for Endangered Species Act-listed Southern Resident orcas and more than 100 other species of fish and animals.

Loss of Economic Opportunities for Commercial Fishing Families in the Pacific Northwest

Salmon were once the pillar of commercial fisheries on the West Coast. Commercial salmon troll fishery—composed of small ocean-going boats, independently owned and operated, that catch Chinook salmon one at a time on hook and line gear—depends upon the number of Columbia-Snake River Basin Chinook that survive to become adults.

The four lower Snake River dams and their reservoirs are a leading cause of mortality for these fish. The dams have dangerously extended salmon’s travel time to the ocean. Before the dams were constructed, juvenile salmon could travel—pushed by the cold, clear spring freshet—from their natal spawning grounds to the Pacific Ocean in as little as a week. Today, for those fish that survive the often-lethal out-migration through the federal hydro-system, it now requires more than a month for the fish to actively swim to the ocean. Wild salmon populations are currently at just 1-3 percent historic run levels, and in the past five years, wild Snake River Spring/Summer Chinook numbers averaged less than half of their total return when the fish were first listed under the ESA in 1992. Washington and Oregon’s fisheries managers closely monitor salmon fishing week to week and make in-season catch adjustments necessary to protect and sustain the fish over time.¹ The extremely low returns of adult salmon these days often leads to emergency commercial fishing closures with only 24 hours notice. Fishing closures may last for a few days or weeks or until the following year.^2,3

For some historical perspective, consider this: In 1949, the State of Washington Department of Fisheries’ managers warned about the harmful effect of hydropower development in the Snake River Basin and predicted the four dams proposed at that time would cause devastating impacts to Snake River-origin fisheries and communities that rely on fishing jobs.⁴ Policymakers failed to heed the scientists' admonitions and build the dams anyway. For decades now, salmon populations and the commercial fishing families that rely on them have declined and suffered as predicted almost a century ago. From 1971 to 1975, the salmon catch of the troll fishery was valued at an average of $21.8 million annually,⁵ but in 2022, the catch was worth $3.1 million;⁶ this is over 90% loss of economic value. In 1978, there were 3041 salmon fishermen, licensed and based in Washington, operating salmon trollers in the coastal waters across Washington to Southeast Alaska.⁷ By 2018, the number had fallen to 102 boats, and in 2022, the number fell to 79 boats.⁸

The devastating economic losses for the commercial fishing fleet are also felt in coastal communities as jobs generated and/or supported by the salmon fishing industry disappear. Commercial salmon fisheries support land based jobs in, for example, fishing gear stores, boat and engine repair businesses, grocery stores, restaurants, and marinas, and bring tax dollars into communities to support local investments such as schools, hospitals, and vital infrastructure. Today, as fewer harvestable salmon are available, there has been a loss of approximately 6,000 jobs in the West Coast fishing fleet and more in onshore businesses that provide services, supplies, and equipment to the fleet as well as investments to local communities and infrastructure.⁹

In recognition of the extinction crisis facing many Northwest salmon populations, more than 229 food professionals - chefs, brewers, market owners, farmers, fishermen, and others from across Washington State – sent a letter in 2022 to Gov. Jay Inslee, Sen. Patty Murray, and Sen. Maria Cantwell to thank them for their past efforts to protect salmon and encouraged them to develop and deliver a comprehensive solution that recovers healthy salmon populations by removing the four lower Snake River dams, replace their services, and invest in communities in a manner that brings everyone forward together.

The letter states, “salmon is much more than a fish; it is one of our most valued business partners. The health and availability of salmon here in the Pacific Northwest impacts our bottom line and our ability to maintain good jobs for the people we employ, provide healthy food for our customers, and feed our own families.” The letter stresses that “decades of trial and error have demonstrated that well-managed fisheries by themselves are not enough to assure sufficient numbers of salmon to drive the economic engine, jobs, and businesses they support.”

“When I was a kid in the ‘70’s I remember how the surface shimmered red when the sockeye came home to spawn. I also sadly remember the story of Lonesome Larry, the only sockeye that made it home to the Salmon River’s headwaters. This was in 1992, and my heart broke when I heard the news. I’m passionate about restoring salmon abundance. This isn’t a debate about borders, or what side of the state you are on. It’s about prioritizing healthy salmon and healthy communities!”

–Chef Robin Leventhal, instructor at the Wine Country Culinary Institute in Walla Walla.

Protecting, restoring, and reconnecting healthy and resilient habitat is essential to Snake River salmon and steelhead survival and recovery. And it is imperative for the Tribal cultures, coastal communities, and fishing families that rely upon the fish.

A free-flowing river benefiting commercial fishing and coastal communities

“The four lower Snake River dams are doing more than holding up fish and making the water warmer, they are impacting the economies of coastal communities and inland communities above them. When we remove the dams and replace their services, we need to make sure Snake River salmon, water, and other resources are healthy and abundant for Tribes, farmers, fishermen, and others to use.”

– Amy Grondin, Commercial Fisherman and Co-owner of Duna Fisheries

The loss of jobs and economic opportunities for commercial salmon fishing families provide evidence over  fifty years of hardship due to the four lower Snake River dams. The restoration of Snake River salmon by removing the four lower Snake River dams offers great economic opportunity for both the ocean salmon troll and Columbia-Snake River Basin commercial fisheries and many, many others.

View the past Hot Water Report issues here: Hot Water Reports - Compiled

References:
1. Save Our wild Salmon: The Importance of Commercial and Recreational Fishing in WA, 2020. pg.6
2. Spokesman-Review: Helen Neville: The need to breach the Lower Snake River dams: A look at 2022 fish returns
3. Save Our wild Salmon: The Importance of Commerical and Recreational Fishing in WA, 2020 pg.6
4. Alvin Anderson, State of WA Dept of Fisheries Annual Report for 1949
5. Pacific Salmon Commission, Economic impacts of Pacific Salmon Fisheries, 2018
6. Pacific Salmon Commission, Economic impacts of Pacific Salmon Fisheries, 2022
7. Pacific Salmon Commission, Economic impacts of Pacific Salmon Fisheries, 2018
8. Pacific Salmon Commission, Economic impacts of Pacific Salmon Fisheries, 2022
9. Lower Snake River Dams: Benefit Replacement Report, August 2022

Sockeye salmon with lesions dying from hot water in the Columbia-Snake River Basin ©Conrad Gowell

I. INTRODUCTION

Welcome to the 2023 Hot Water Report: Warming Waters in the Lower Snake and Columbia Rivers.

During the summer, this weekly report provides an update on real-time water temperatures in the lower Snake and Columbia River reservoirs via graphs and analyses, a summary of the highest weekly water temperatures at the forebay/reservoir of each federal dam, and a monthly status of adult returns for different salmon and steelhead populations as they make their way back to their natal spawning grounds. We’ll report first-hand from scientists, Tribal members, fishing guides, advocates, and other experts about the challenges facing these rivers – and our opportunities to improve and restore them - in order to recover healthy, resilient fish populations and the benefits they deliver to Northwest communities, other fish and wildlife populations (including the critically endangered Southern Resident orca), and ecosystems.

Many once-abundant anadromous fish populations - fish that hatch in freshwater, go to sea, and return to freshwater to spawn - in the Columbia-Snake River Basin are on the brink of extinction today due primarily to harms caused by federal dams and their warming reservoirs. The Columbia-Snake federal hydro-system harms and kills both juvenile and adult fish in multiple ways, including by elevating water temperatures in the summer months in their large, stagnant reservoirs. These cold-water fish begin to suffer harmful effects when water temperatures exceed 68° Fahrenheit.

This week, on the lower Snake River, the reservoir behind the Ice Harbor Dam registered the highest water temperature at 72.36°F on August 5. Both juvenile and adult salmon have experienced water temperatures above the 68°F “harm” threshold for over a month this summer. In Issue 6, Miles Johnson, Legal Director for Columbia Riverkeeper, uncovers the critical role of the Clean Water Act in addressing dams’ hot water pollution, also known as heat pollution, to protect endangered salmon and steelhead from extinction. This issue provides an in-depth review of how federal agencies such as the U. S. Army Corps of Engineers and the Bonneville Power Administration have purposely delayed the implementation of the Clean Water Act’s requirements to address heat pollution for over two decades.

The four federal dams and their hot water reservoirs on the lower Snake River continue to be main obstacle to salmon and steelhead recovery. We urgently need federal agencies—especially the Army Corps of Engineers and Bonneville Power Administration—to actively support comprehensive regional solutions that include the removal of the lower Snake River dams and replacement of their services in order to restore a healthier, cooler and resilient lower Snake River, uphold our nation's promises to Tribes and sustain salmon populations in perpetuity.

The Hot Water Report is a joint project of the Save Our wild Salmon Coalition, American Rivers, Association of Northwest Steelheaders, Columbia Riverkeeper, Earthjustice, Endangered Species Coalition, Environment Oregon, Idaho Conservation League, Idaho Rivers United, Natural Resources Defense Council, National Wildlife Federation, Northwest Sportfishing Industry Association, Orca Network, Sierra Club, Snake River Waterkeeper, Wild Orca and Wild Steelhead Coalition.

II. READING THE DATA - Water Temperatures in the Lower Snake and Columbia Rivers

Figure 1. Lower Snake River Water Temperatures - 2023 Daily Average and 10-year Average. Click on the image to view the graph.

Introduction to the data:
The daily average temperature at the four reservoir forebays (measured with sensors stationed at various depths below the reservoir surface, immediately upstream from the dam) in the lower Snake River (shown above) and the lower Columbia River (shown below) for 2023 is represented with solid lines and the 10-year average (2013 - 2023) temperatures with dashed lines of the same color. The dotted line across the graph represents the 68°F “harm threshold” for adult and juvenile fish.

The longer and the higher these temperatures rise above 68°F, the greater the harm, including: migration disruption, increased metabolism, increased susceptibility to disease, reduced reproductive potential (by reducing egg viability), suffocation (warm water carries less dissolved oxygen), and in the worst case - death.

Reservoirs are large, stagnant pools that absorb enormous amounts of solar radiation, and cause the water to warm. These waters inundate and destroy diverse micro-habitats that healthy rivers support, including cold-water refuges that salmon and steelhead rely upon during their migration. Without these vital pockets of cold water, salmonids cannot rest and recover on their journeys—adults moving upstream to spawn and juveniles moving downstream to the ocean. Rising temperatures and reductions in snowpack in recent decades due to climate change create warmer waters, which results in lower survival and reduced reproductive success for salmon and steelhead.

Figure 2. Lower Columbia River Water Temperatures - 2023 Daily Average and 10-year Average. Click on the image to view the graph.

Discussion of data:
Since April, temperatures in the lower Snake River and the lower Columbia River reservoirs have steadily increased. As Figure 1 shows, this week, the reservoir behind the Ice Harbor Dam had the highest average temperature of 71.97°F from August 6. Lower Monumental Dam's reservoir had the second highest average temperature of 71.09°F on August 6.

As Figure 2 shows, this week the reservoirs behind The Dalles and John Day dams registered the highest average temperature of 71.60°F.

Both juvenile and adult salmon have now experienced water temperatures consistently above the 68°F “harm” threshold for more than a month.

Below, we present the weekly high water temperatures for each reservoir on the lower Snake and Columbia rivers for August 3 - August 8.

A note on the data: The 2023 lower Snake River and lower Columbia River water temperature data presented in the Hot Water Report are collected from the Columbia River DART program by Columbia Basin Research, University of Washington, using data courtesy of the U.S. Army Corps of Engineers (USACE). The 10-year average water temperature data is courtesy of the Fish Passage Center. There is no data available for the Lower Monumental 10-year average water temperature, and McNary reservoir water temperature data is collected from USACE with current available data. Graphs and tables were assembled by SOS Staff.

 III. WEEKLY HIGH WATER TEMPERATURES: August 3 - August 8

This week, on the lower Snake River, the reservoir behind the Ice Harbor Dam registered the highest water temperature at 72.36°F on August 5, and the Lower Monumental Dam registered the second highest temperature at 71.20°F on August 6.

This week, on the lower Columbia River, The Dalles Dam reservoir registered the highest water temperature at 72.32°F on August 8.

IV. Hot water vs. the Clean Water Act
by Miles Johnson, Columbia Riverkeeper, Legal Director

The Clean Water Act is our nation's flagship law for protecting healthy streams, rivers, and lakes. Enacted when some of our nation’s waterways were so contaminated that they actually caught fire, the Clean Water Act’s common-sense goal is to ensure that rivers and lakes remain clean enough to support fishing, swimming, and (after appropriate treatment) drinking. Although significant threats to water quality obviously remain, the Clean Water Act has proven to be one of our nation’s most effective—and most popular—environmental laws.

All of this prompts the question: Does the Clean Water Act contain the tools and authorities to address hot water pollution caused by dams on the Lower Snake and Columbia rivers? In theory, the answer is yes. Columbia Riverkeeper and others are working hard to translate that theory into action to protect endangered salmon and steelhead from the dams’ heat pollution.

Here is a quick tour of the legal landscape: The Clean Water Act defines heat as a pollutant. The states of Oregon and Washington long ago recognized that the Columbia and Lower Snake rivers have too much heat pollution to safely support salmon and steelhead. After litigation by Columbia Riverkeeper and others in 2021, the U.S. Environmental Protection Agency (EPA) issued a heat pollution budget (called a Total Maximum Daily Load analysis or TMDL) for these rivers. EPA’s heat pollution budget identified the dams as the largest sources of heat pollution and calculated each dam’s heat pollution limit.¹ New Clean Water Act discharge permits for the dams (issued because of recent litigation by Columbia Riverkeeper) made EPA’s heat pollution limits enforceable and required the Army Corps to develop plans to reduce its dams’ heat pollution.

If the Clean Water Act applies to heat pollution, why are we just beginning to regulate heat pollution from these dams? Unfortunately, the federal agencies that operate the dams and sell the electricity have long sought to obscure, and avoid responsibility for, their dams’ heat pollution. Nearly twenty years ago, the Army Corps prevailed upon EPA to bury a draft of the heat pollution TMDL. When EPA took up the draft TMDL again several years later, the Army Corps asked EPA to pretend that the temperature impacts of the dams were part of the natural river system and beyond the reach of the Clean Water Act. Rebuffed, and concerned that EPA would issue a TMDL limiting heat pollution from the dams, the Army Corps pressured Oregon to eliminate salmon and steelhead as Clean Water Act-protected uses of the Columbia River² (an invitation Former Oregon Governor Kulongoski pointedly refused). After EPA finally issued the heat pollution TMDL, the Army Corps unsuccessfully appealed a decision by the Washington Department of Ecology that made the TMDL’s heat pollution limits legally enforceable.³ In short, the Army Corps and other federal dam agencies like Bonneville Power Administration have purposely delayed the implementation of the Clean Water Act’s basic requirements for over two decades. Meanwhile, Snake River salmon and steelhead moved steadily towards extinction.

Sockeye salmon with lesions dying from hot water in the Columbia-Snake River Basin ©Conrad Gowell

What will happen next? Despite the Army Corps’ prolonged resistance, new Clean Water Act discharge permits require the Army Corps to create and implement plans to meet the TMDL’s heat pollution reduction targets for each dam. The plans must evaluate actions such as drawing down (lowering the level of) reservoirs during hot months to reduce heat pollution. Indeed, the Army Corps has submitted the outline of its plans for the lower Snake River dams; they identify operating the reservoirs below the Minimum Operating Pool level as one of the Army Corps’ “Future Measures/Strategies” to address the dams’ heat pollution. (Note: The Minimum Operating Pool (MOP) is the reservoir level where barges can use the river. Operating below MOP would also significantly decrease power generation.)  

Refining and implementing these studies will take several years. If the Army Corps’ past reluctance to comply with the Clean Water Act is any guide, Columbia Riverkeeper and others will need to remain engaged to ensure outcomes that actually benefit salmon and steelhead. However, if the Army Corps doesn’t make and implement water quality attainment plans and meet the TMDL’s heat pollution limits, the Army Corps will continue to be vulnerable to Clean Water Act enforcement lawsuits. The Washington Department of Ecology could also revoke the Army Corps’ Clean Water Act certifications, which would cast into doubt the Army Corps’ legal authority to continue operating the dams.

The bottom line remains: Wild salmon and steelhead who return to the Snake River Basin are struggling for survival. Hot water continues to be a major driver of fish mortality. The federal agencies—especially the Army Corps of Engineers and Bonneville Power Administration—persistently seek to mislead, obfuscate, delay, and deny. Today, they are part of the problem when we need them to be part of the solution. Their bad behavior is driving up salmon recovery costs and underscores the urgent need for the Biden Administration to deliver a comprehensive regional solution that includes the removal of the lower Snake River dams and replacement of their services—as quickly as humanly possible!

View the past Hot Water Report issues here: Hot Water Reports - Compiled

References:
1. U.S. EPA, Columbia and Lower Snake River Temperature TMDL, pp. 55–59 (Aug. 13, 2021) (Columns E and F in Tables 6-6 through 6-10 show the heat pollution caused by the four Lower Snake River dams individually and cumulatively during the summer and fall.).
2. See, e.g., Letter from Army Corps, Bureau of Reclamation, and EPA to Oregon Department of Environmental Quality encouraging Use Attainability Analyses for the Columbia and Snake Rivers(May 9, 2005).
3. See, e.g., Army Corps, Notice of Appeal to the Washington Pollution Control Hearings Board re Ecology Order No. 18146 Granting Water Quality Certification for the Bonneville Project(June 8, 2020).

 V. Snake River sockeye run sputters - an article by Eric Barker, Lewiston Tribune

“Strong early numbers at Bonneville Dam haven’t led to a lot of fish making it to Lower Granite Dam. The promising start to the Snake River sockeye run appears to have melted away as the adult fish progressed upstream.

Sockeye that return to Redfish, Pettit and Alturas lakes in the shadow of Idaho’s Sawtooth Mountains are the most imperiled salmon run in the Columbia River basin and listed as endangered by the federal government. But in mid-July, fisheries managers at the Idaho Department of Fish and Game were hopeful at the number of Idaho-bound sockeye detected at Bonneville Dam, the first in a series of dams salmon and steelhead from the Columbia and Snake rivers must pass on their way home. They estimated 4,351 had navigated past the dam, a number that would be the most since 2012.

Even so, there already were signs that those fish faced tough conditions. Flows in the Columbia and Snake were dropping and water temperatures were already above seasonal norms at federal dams on the two rivers.

On average, 40% to 70% of adult Snake River sockeye counted at Bonneville Dam make it to Lower Granite Dam on the Snake River. Known as conversion, the rate varies based on river conditions.

In mid-July, Eric Johnson, a sockeye specialist with the Idaho Department of Fish and Game, predicted survival would be in the 40% range this year. Fast forward two weeks and the Bonneville-to-Granite conversion rate is only at 20%. That compares to a conversion rate of 66% in 2022.

'It’s definitely lower than average and lower than we would have hoped for,' Johnson said. 'We are not completely through the run. I expect that it will probably improve a little bit but I’m not expecting it’s going to improve too much.'”

Read the full article here.

Sockeye salmon with lesions dying from hot water in the Columbia-Snake River Basin ©Conrad Gowell

I. INTRODUCTION

Welcome to the 2023 Hot Water Report: Warming Waters in the lower Snake and Columbia rivers.

During the summer, this weekly report provides an update on real-time water temperatures in the lower Snake and Columbia river reservoirs via graphs and analyses, a summary of the highest weekly water temperatures at the forebay/reservoir of each dam, and a monthly status of adult returns for different salmon and steelhead populations as they make their way back to their natal spawning grounds. We’ll report first-hand from scientists, Tribal members, fishing guides, advocates, and other experts about the challenges facing these rivers - and our opportunities to improve and restore them - in order to recover healthy, resilient fish populations and the benefits they deliver to Northwest communities, other fish and wildlife populations (including the critically endangered Southern Resident orca), and ecosystems.

The once-abundant anadromous fish populations of the Columbia-Snake River Basin are on the brink of extinction today due primarily to harms caused by federal dams and their warming reservoirs. The Columbia-Snake federal hydro-system harms and kills both juvenile and adult fish in multiple ways, including by elevating water temperatures in the summer months in their large, stagnant reservoirs. These cold-water fish begin to suffer harmful effects when water temperatures exceed 68° Fahrenheit.

This July marked the first time in 2023 the lower Snake and Columbia river reservoirs surpassed the 68°F “harm” threshold for salmon and steelhead, and now salmon are migrating through dangerous and lethal water temperatures. In Issue 2, we’ll review the water temperatures suitable for juvenile and adult salmon as well as lethal, and the urgent need to restore a freely flowing lower Snake River to provide cold, clean, and healthy waters for salmon and steelhead.

A restored, healthy, and resilient lower Snake River is a necessary step in order to uphold our nation's promises to Tribes and sustain salmon populations in perpetuity. Dam removal will reconnect the Northwest’s emblematic fish to over 5,500 miles of pristine, cold-water river and streams in Idaho, Oregon, and Washington.

The Hot Water Report is a joint project of the Save Our wild Salmon Coalition, Association of Northwest Steelheaders, Columbia Riverkeeper, Earthjustice, Endangered Species Coalition, Environment Oregon, Idaho Conservation League, Idaho Rivers United, Natural Resources Defense Council, National Wildlife Federation, Northwest Sportfishing Industry Association, Orca Network, Sierra Club, Snake River Waterkeeper, Wild Orca and Wild Steelhead Coalition.

II. READING THE DATA - Lower Snake and Columbia River Temperatures

Figure 1. Lower Snake River Water Temperatures - 2023 Daily Average and 10-year Average. Click on the image to view the graph.

Introduction to the data:

The daily average temperature at the four reservoir forebays (immediately upstream from the dam) in the lower Snake River (above) and the lower Columbia River (below) for 2023 is represented with solid lines and the 10-year average (2013 - 2023) temperatures with dashed lines of the same color. The dotted line across the graph represents the 68°F “harm threshold” for adult and juvenile fish.

The longer and the higher these temperatures rise above 68°F, the greater the harm, including: migration disruption, increased metabolism, increased susceptibility to disease, reduced reproductive potential (by reducing egg viability), suffocation (warm water carries less oxygen), and in the worst case - death.

Reservoirs are large, slow-moving pools that absorb enormous amounts of solar radiation, causing waters to warm. These waters inundate and destroy diverse micro-habitats that healthy rivers support, including cold-water refuges that salmon and steelhead rely upon during summer migrations. Without these vital pockets of cold water, salmonids struggle to rest and recover on their journeys – adults moving upstream to spawn and juveniles moving downstream to the ocean. Rising temperatures and reductions in snowpack in recent decades due to climate change create warmer waters, which results in lower survival and reduced reproductive success for salmon and steelhead. The lower Snake River dams and their reservoirs exacerbate these already-warmed waters, creating conditions that harm these fish.

Figure 2. Lower Columbia River Water Temperatures - 2023 Daily Average and 10-year Average. Click on the image to view the graph.

Discussion of data:

Since April, temperatures in the lower Snake River and the lower Columbia River reservoirs have steadily increased. Water temperatures in June this year were considerably higher than 10-year average. As Figure 1 shows, this week, the reservoir behind the Ice Harbor Dam had the highest recorded average temperature of 69.45°F on July 11. The Little Goose reservoir had the second highest recorded average temperature of 69.42°F on July 8.

As Figure 2 shows, the reservoir behind the John Day dam on the lower Columbia River had the highest recorded average temperature of 70.34°F on July 6. Both juvenile and adult salmon are now experiencing water temperatures 1- 2 degrees above the 68°F “harm” threshold.

Last week, on the lower Snake River, the reservoir behind the Lower Granite Dam had the highest recorded average temperature of 68.63°F on July 5. This week, however, the pool behind Lower Granite Dam fell to an average temperature of 65.71°F on July 11. This significant decrease in temperatures is the result of the US Army Corps of Engineers’ annual summer release of cold waters from the Dworshak reservoir into the Clearwater River, a tributary to the lower Snake River. The goal of this release is to lower water temperatures and aid salmon migration, but the benefit of this cold water does not last long in the heat of the summer and does not cool the other three downstream reservoirs. With a free-flowing lower Snake River, the additional benefit of cold waters released from the Dworshak reservoir will extenddown the lower Snake River to its confluence with the Columbia River.

Below, we present the highest temperatures for each reservoir on the lower Snake and Columbia rivers for July 6 - July 11.

A note on the data: The 2023 lower Snake River and lower Columbia River water temperature data presented in the Hot Water Report are collected from the Columbia River DART program by Columbia Basin Research, University of Washington, using data courtesy of the U.S. Army Corps of Engineers (USACE). The 10-year average water temperature data is courtesy of the Fish Passage Center. There is no data available for the Lower Monumental 10-year average water temperature, and McNary reservoir water temperature data is collected from USACE with current available data. Graphs and tables were assembled by SOS Staff.

 III. WEEKLY HIGH TEMPERATURES: 7/6 - 7/11

On the lower Snake River, the reservoir behind the Ice Harbor reservoir registered the highest water temperature at 70.02°F on July 11, and the Little Goose Dam registered the second highest temperature at 69.98°F on July 8.

On the lower Columbia River, the John Day reservoir registered the highest water temperature at 71.24°F on July 6.

IV. Salmon and Steelhead are in Hot Water

Sockeye salmon with lesions dying from hot water in the Columbia-Snake River Basin ©Conrad Gowell, July 2021

This July marked the first time in 2023 the lower Snake and Columbia river reservoirs surpassed the 68°F “harm” threshold for salmon and steelhead. This week, the Ice Harbor reservoir registered the highest water temperature at 70.02°F on July 11, and the John Day reservoir reached 71.24°F on July 6 – both temperatures significantly exceed the legal (and biological) limit of 68°F, which scientists have identified as critical for protecting salmon. Salmon and steelhead are now in hot water.

Hot Water Temperatures and Their Impact on Salmon

Dead sockeye hangs upside down in Columbia River. ©Conrad Gowell, July 2021

Salmon require cold, clean water and freshwater habitat to thrive and complete their ancestral migration. The once free-flowing river has been transformed into reservoirs that produce lethal high water temperatures and significantly reduce access to the cold-water, high-quality spawning, and nursery habitat that are essential for fish sustainability.¹

Below is a brief list of temperature ranges suitable and lethal to salmon and steelhead:

• Although varying by species, life stage, and season, the optimal range for juvenile and adult salmon in this region is 55-64°F.²
• 68°F: Adult salmon have difficulty migrating upstream when water temperatures approach 68°F.
• 69°F: As temperatures reach 69°F, salmon become sluggish.³ An increase of even a few degrees above the optimum range can change migration timing, reduce growth rates, reduce available oxygen, and increase susceptibility to parasites, predators, and disease.⁴ Warm water temperature can alter growth and development rates for juvenile salmon.⁵
• 70°F: Stream temperatures of 70°F and above are extremely stressful for most species,⁶ stress including concurrent thermal stress and energy depletion.⁷ As of July 2023, water temperatures are reaching between 68 - 71°F.
• 72-73°F: Migration stops altogether when water temperatures reach 72-73°F. Salmon that have stopped or slowed their migration, and languish for days or weeks in warm water, begin dying from thermal stress and disease.⁸
• 77°F and above: If salmon are exposed to water above 77°F for more than 24 hours, they will die.⁹

Restoring the lower Snake River by removing its four federal dams is an essential cornerstone for any credible regional salmon recovery strategy. Up to 70 percent of total out-migrating smolts are killed each year before they reach the ocean as a result of dam encounters, hot stagnant reservoirs, predation, and extended travel time.¹⁰ A letter signed by 68 national and Northwest scientists stated, “These four dams must be removed not only to avoid extinction of Snake River fish, but, because these dams block the gateway to high quality, resilient spawning habitat in a world facing increasing impacts of climate change, their removal is essential to restore abundant, harvestable salmon,... and honor the nation’s promises to Northwest Tribes.”¹¹

Salmon need cold, clean water

Scientists state excessively high water temperatures above 68°F, are now normal for extended periods in July, August, and September in the lower Snake River. In the summer of 2015, 96 percent of the returning adult Snake River sockeye salmon run died prematurely (pre-spawn) in the lower Snake and Columbia rivers because the reservoirs, coupled with record air temperature and low flows, caused the water to become too warm.¹² In early July 2021, video footage showed heat-stressed sockeye salmon with large, open lesions and fungus returning to the Columbia and Snake rivers in waters exceeding 71°F, leading Oregon and Washington to order drastic emergency fishing closures. Scientists predict this year will be another summer of lethally hot water conditions for endangered salmon and steelhead.

“The Snake basin contains the largest area of high-quality Pacific salmon and steelhead habitat left in the lower 48 states. This habitat is increasingly important for them as climate change proceeds, providing a haven of cold waters and the habitat integrity and complexity they need to build and maintain healthy, resilient populations. And yet, even here in the best of the best habitat remaining, the impact of the dams on our salmon and steelhead is unquestionable. Downstream, salmon and steelhead populations on the John Day Rivers and Yakima Rivers must cross three and four dams, respectively. These populations are returning at sustainable rates, nearly four times as high as salmon and steelhead in the Snake basin, which must cross 8 dams and are reaching critical thresholds of risk.”

– Helen Neville, Senior Scientist, Trout Unlimited¹³

In a published reportby Columbia Riverkeeper – ‘Columbia Riverkeeper White Paper: Computer modeling shows that Lower Snake River dams caused dangerously hot water for salmon in 2015’ – confirmed, through computer modeling, “A cooler, free-flowing Lower Snake River could provide refuge for endangered sockeye and other salmon that survive the first part of their difficult journey—rather than forcing these fish to migrate through another 140 miles of hot, stagnant reservoirs. A free-flowing lower Snake River would create opportunities and flexibility, both for migrating salmon and for the state, federal, and tribal governments working to recover these iconic fish.”¹⁴

The American Fisheries Society (AFS) and the Western Division AFS, in a statement, affirmed that “breaching the four lower Snake River dams would provide greater certainty of achieving long-term survival and restore riverine habitats in the lower Snake River that will also benefit ecosystem processes, entire biological communities, and increase climate change resilience of anadromous fishes.¹⁵

The science is clear: salmon are headed to extinction unless we remove the four lower Snake River dams and replace the dams' services. Salmon and steelhead desperately need a cold free-flowing lower Snake River to ensure resilient and abundant salmon and steelhead populations for generations to come.

View the Hot Water Report Issue 1 and past issues here: Hot Water Reports - Compiled

References:
1, 15. Statement of the American Fisheries Society (AFS) and the Western Division AFS (WDAFS) About the Need to Breach the Four Dams on the Lower Snake River
2, 4, 6. A Great Wave Rising: Solutions for Columbia and Snake River Salmon and McCullough, D.A., 1999. “A Review and Synthesis of Effects of Alterations to the Water Temperature Regime on Freshwater Life Stages of Salmonids, With Special Reference to Chinook Salmon.” Region 10 Water Resources Assessment Report No. 910-R-99-010
3. National Wildlife Federation: How Water Temperatures affect salmon
5, 7. Poole, G., et al., 2001. Technical Synthesis: Scientific Issues Relating to Temperature Criteria for Salmon, Trout, and Char Native to the Pacific Northwest
8, 12, 14. Columbia Riverkeeper White Paper - Computer modeling shows that Lower Snake River dams caused dangerously hot water for salmon in 2015.
9. Columbia River Inter-Tribal Fish Commission: Climate Change
10. Save Our wild Salmon Press Release: Congressional field hearing ignores the urgency for protecting salmon from extinction and opportunity to invest in Northwest communities and infrastructure
11. Scientists’ letter on the need for lower Snake River dam removal to protect salmon and steelhead from extinction and restore abundant, fishable populations.
13. Spokesman-Review: Helen Neville: The need to breach the Lower Snake River dams: A look at 2022 fish returns 

Sockeye salmon with lesions dying from hot water in the Columbia-Snake River Basin ©Conrad Gowell

I. INTRODUCTION

Welcome to the 2023 Hot Water Report: Warming Waters in the lower Snake and Columbia Rivers.

During the summer, this weekly report provides an update on real-time water temperatures in the lower Snake and Columbia River reservoirs via graphs and analyses, a summary of the highest weekly water temperatures at the forebay/reservoir of each dam, and a monthly status of adult returns for different salmon and steelhead populations as they make their way back to their natal spawning grounds. We’ll report first-hand from scientists, Tribal members, fishing guides, advocates, and other experts about the challenges facing these rivers - and our opportunities to improve and restore them - in order to recover healthy, resilient fish populations and the benefits they deliver to Northwest communities, other fish and wildlife populations (including the critically endangered Southern Resident orca), and ecosystems.

The once-abundant anadromous fish populations of the Columbia-Snake River Basin are on the brink of extinction today due primarily to harms caused by federal dams and their warming reservoirs. The Columbia-Snake federal hydro-system harms and kills both juvenile and adult fish in multiple ways, including by elevating water temperatures in the summer months in their large, stagnant reservoirs. These cold-water fish begin to suffer harmful effects when water temperatures exceed 68° Fahrenheit.

This week, on the lower Snake River, the reservoir behind the Ice Harbor Dam registered the highest water temperature at 71.98°F on July 18 –  over 3 degrees above the 68°F “harm" threshold set to protect salmon and steelhead from extinction.In Issue 3, we’ll explore historical and 2022 wild Snake River salmon and steelhead returns and compare the returns to their established recovery goals – the adult returns deemed necessary to recover these populations and remove them from the Endangered Species Act list. Since the four lower Snake River dams were built over 60 years ago, Snake River salmon and steelhead returns have declined and remained far below the recovery goals necessary to remove them from the Endangered Species Act list. Without immediate and meaningful conservation actions, scientists predict we will lose these fish forever.

A restored, healthy, and resilient lower Snake River is a necessary step in order to uphold our nation's promises to Tribes and sustain salmon populations in perpetuity.

The Hot Water Report is a joint project of the Save Our wild Salmon Coalition, American Rivers, Association of Northwest Steelheaders, Columbia Riverkeeper, Earthjustice, Endangered Species Coalition, Environment Oregon, Idaho Conservation League, Idaho Rivers United, Natural Resources Defense Council, National Wildlife Federation, Northwest Sportfishing Industry Association, Orca Network, Sierra Club, Snake River Waterkeeper, Wild Orca and Wild Steelhead Coalition.

II. READING THE DATA - Lower Snake and Columbia River Temperatures

Figure 1. Lower Snake River Water Temperatures - 2023 Daily Average and 10-year Average. Click on the image to view the graph.

Introduction to the data:
The daily average temperature at the four reservoir forebays (measured with sensors stationed at various depths below the reservoir surface, immediately upstream from the dam) in the lower Snake River (above) and the lower Columbia River (below) for 2023 is represented with solid lines and the 10-year average (2013 - 2023) temperatures with dashed lines of the same color. The dotted line across the graph represents the 68°F “harm threshold” for adult and juvenile fish.

The longer and the higher these temperatures rise above 68°F, the greater the harm, including: migration disruption, increased metabolism, increased susceptibility to disease, reduced reproductive potential (by reducing egg viability), suffocation (warm water carries less dissolved oxygen), and in the worst case - death.

Reservoirs are large, stagnant pools that can absorb enormous amounts of solar radiation, and cause waters to warm. These waters inundate and destroy diverse micro-habitats that healthy rivers support, including cold-water refuges that salmon and steelhead rely upon during their migration. Without these vital pockets of cold water, salmonids cannot rest and recover on their journeys – adults moving upstream to spawn and juveniles moving downstream to the ocean. Rising temperatures and reductions in snowpack in recent decades due to climate change create warmer waters, which results in lower survival and reduced reproductive success for salmon and steelhead. 

Figure 2. Lower Columbia River Water Temperatures - 2023 Daily Average and 10-year Average. Click on the image to view the graph.

Discussion of data:
Since April, temperatures in the lower Snake River and the lower Columbia River reservoirs have steadily increased. As Figure 1 shows, this week, the reservoir behind the Ice Harbor Dam had the highest average temperature of 71.99°F on July 16 and July 18. The Lower Monumental reservoir had the second highest average temperature of 69.67°F on July 12.

As Figure 2 shows, this week, the reservoir behind the Bonneville dam had the highest average temperature of 71.42°F on July 16. Both juvenile and adult salmon are now experiencing water temperatures 1- 3 degrees above the 68°F “harm” threshold in several of the reservoirs they pass.

On the lower Snake River, the reservoir behind the Lower Granite Dam recorded an average temperature of 68.63°F on July 5. This week, however, the pool behind Lower Granite Dam fell to an average temperature of 67.1°F on July 18. This decrease in temperatures is the result of the US Army Corps of Engineers’ annual summer release of cold waters from the Dworshak reservoir into the Clearwater River, a tributary to the lower Snake River. The goal of this release is to lower water temperatures and aid salmon migration, but the benefit of this cold water does not last long in the heat of the summer and does not cool the other three downstream reservoirs. By restoring a freely flowing lower Snake River, the additional benefit of cold waters released from the Dworshak reservoir will extend down the lower Snake River to its confluence with the Columbia River.

Below, we present the weekly high temperatures for each reservoir on the lower Snake and Columbia rivers for July 12 - July 18.

A note on the data: The 2023 lower Snake River and lower Columbia River water temperature data presented in the Hot Water Report are collected from the Columbia River DART program by Columbia Basin Research, University of Washington, using data courtesy of the U.S. Army Corps of Engineers (USACE). The 10-year average water temperature data is courtesy of the Fish Passage Center. There is no data available for the Lower Monumental 10-year average water temperature, and McNary reservoir water temperature data is collected from USACE with current available data. Graphs and tables were assembled by SOS Staff.

III. WEEKLY HIGH TEMPERATURES: 7/12 - 7/18

This week, on the lower Snake River, the reservoir behind the Ice Harbor Dam registered the highest water temperature at 71.98°F on July 18, and the Lower Monumental Dam registered the second highest temperature at 70.12°F on July 18.

This week, on the lower Columbia River, the Bonneville reservoir registered the highest water temperature at 71.96°F on July 16.

IV. A Look at Snake River Wild Salmon & Steelhead Adult Returns

The Snake River's anadromous fish populations have been on a steady downward trajectory for decades. These salmon and steelhead face multiple obstacles, including increasingly hot water in the summer months in the lower Snake River reservoirs. Below, we present background information on the status of native fish returns, including (1) wild Snake River Spring/Summer Chinook, (2) wild steelhead, and (3) wild/natural sockeye. We will also look at how the historical and 2022 adult returns compare to established recovery goals – the adult fish returns deemed necessary to recover these populations to abundance and remove them from the Endangered Species Act list.

In summary - since the four lower Snake River dams were built, over 60 years ago, Snake River salmon and steelhead populations have steadily declined. Long before the dams were built, scientists projected that the construction of the lower Snake River dams would devastate salmon and steelhead populations. Over the past several decades, these fish have returned annually far below the recovery goals necessary to remove them from the protections of the Endangered Species Act. Without immediate and meaningful conservation actions, scientists predict these populations will continue to decline toward extinction.

A. What Are Wild Salmon and Steelhead Returns?
The size and condition of a given population of salmon or steelhead are typically measured by the number of adult fish that return from the ocean to their upriver spawning grounds each year. The most straightforward method to measure the size of a salmon run is to count the fish as they swim upstream.

Snake River salmon and steelhead runs are counted at Lower Granite Dam, the last impediment on the river before the fish enter thousands of miles of tributary spawning and rearing habitat in central Idaho, Oregon, and Washington. Salmon returns have been counted on the lower Snake River since Ice Harbor Dam was first completed in 1962. This dataset of 60+ years, coupled with informed estimates of run sizes before the dams were constructed, provides valuable insight into the precipitous declines wild salmon and steelhead have experienced in the last 4-5 decades.

B. Historical Context
Historical data for the Columbia and Snake rivers estimates that 10-16 million wild salmon and steelhead entered the Columbia River Basin to spawn, annually, with 2-4 million more utilizing the Snake River watershed.¹ The Columbia River Basin was once home to the largest runs of Chinook salmon in the world, and roughly half of those Chinook returned to the Snake River in the spring and fall seasons about 200 years ago.² The health of these populations has plummeted over time from historic levels that were once in the hundreds of thousands or millions, depending on the particular population.

Any enthusiasm today about a modest uptick in adult returns in a given year is a symptom of what scientists call “the shifting baseline syndrome,” where the perception of what constitutes a healthy population is based only on very recent reference points. These benchmarks today are extraordinarily low due to long-term population declines. The result is that our collective perception of what constitutes a healthy salmon run continually shifts downward. Put simply, since the completion of the dams on the lower Snake River, nearly half of Snake River salmon and steelhead populations have reached quasi-extinction thresholds – a critical threshold signaling they are nearing extinction, and without intervention, many may not persist, according to Nez Perce Tribe fishery scientists.

C. Recovery Goals: Informed By the Past, Potential for the Future
Recovery goals for wild Snake River salmon and steelhead have been set to reflect the healthy runs that returned to Idaho in the 1950s – before the dams were constructed. These goals represent self-sustaining, harvestable populations that the currently available, high-quality habitat in the Snake River Basin can support. Restoring abundant populations will allow salmon to once again function as keystone species, feeding countless animals, forests, and plants, and supporting the Northwest's unique cultures and economies. Restoring the lower Snake River through dam removal is our most significant river and salmon restoration opportunity anywhere in the nation today. A restored, healthy and resilient lower Snake River is necessary to uphold our nation's promises to Tribes by reconnecting this emblematic fish to 5,500 miles of pristine, protected river and streams in Idaho, Oregon, and Washington.

D. Current Status of Snake River Returns

(1) Snake River Spring/Summer Chinook:

• Endangered Species Act Status: Threatened (listed in 1992)
• Historical Annual Return: Over 2 million³
• Recovery Goal: Escapement of 127,000 wild adults per year
• 2022 Wild Returns⁴: 16,462
• Analysis: Spring/summer chinook were once the Pacific Northwest’s most widely distributed and abundant salmon, numbering in the millions.⁵

In the past five years, wild Snake River Spring/Summer Chinook numbers averaged less than half of their total return when the fish were first listed under the ESA in 1992. Despite last year's small improvement in adult return wild spring/summer Chinook (16K total), we remain far from the recovery goal (a minimum of 127K annually), and the population remains in long-term decline and at risk of extinction.⁶

In June 2023, the Oregon Department of Fish and Wildlife (ODFW) and Washington Department of Fish and Wildlife (WDFW) announced an emergency fishing closure after Endangered Species Act limits on listed salmon were exceeded.

“Rather than pointing fingers at a particular fishery, it’s important to acknowledge the real problem, that there are way too few wild Snake River spring/summer Chinook coming back,” said Tucker Jones, ODFW Columbia River Program Manager. “NOAA’s recent ‘Rebuilding Interior Columbia Basin Salmon and Steelhead’ report acknowledges this, and notes that without aggressive, urgent actions, including restoration of the lower Snake River for Snake River spring/summer Chinook, achieving healthy and abundant populations won’t be possible. While fisheries are playing their critical role in the conservation and recovery story, it’s important that the region continue to push other sectors to do the same.”⁷

(2) Snake River Steelhead:

• Endangered Species Act Status: Threatened (listed in 1997)
• Historical Annual Return: Over 1 million⁸
• Recovery Goal: Escapement of 104,500 wild adults per year
• 2021/22 Returns⁹: 9,807
• Analysis: Historic runs of steelhead to the Snake River Basin were estimated to be over one million fish annually.¹⁰ The Snake River and its tributaries produced 55 percent of summer steelhead in the entire Columbia River basin.¹¹ However, today, steelhead are returning below their recovery goal. During the summer of 2021, steelhead saw the lowest returns in history, forcing emergency fishing closures in Washington and Oregon.

(3) Snake River Sockeye:

• Endangered Species Act Status: Endangered (listed in 1991)
• Historical Annual Return: Over 100,000+/yr to central Idaho’s high mountain lakes¹²
• Recovery Goal: 9,000 wild adults per year to the Stanley Basin
• 2022 Wild Returns: 46 wild/natural-origin sockeye returned to the Stanley Basin¹³
• Analysis: Historic runs to Idaho’s high mountain lakes used to be over 100,000+ sockeye per year but have also severely declined over the years.¹⁴ In 1991, the Shoshone-Bannock Tribes successfully petitioned the federal government to list the run under the Endangered Species Act - making Snake River sockeye the first ESA-listed salmonid in the Columbia Basin. According to the Idaho Fish and Game, in 1991, only four adult sockeye returned to the Sawtooth Basin. The total number of sockeye that returned between 1991-99 was 23 fish, including two years when no sockeye returned.¹⁵

Sockeye are particularly susceptible to hot water, and along with summer Chinook, have shifted their run timing earlier to avoid warming river temperatures.¹⁶ In 2015, only 15% of migrating adult Snake River sockeye survived the trip from Bonneville to McNary Dam.¹⁶

Hot water is jeopardizing the existence of this already very fragile population. During the summer of 2021, video footage, and images showed sockeye with large, open lesions and fungus caused by hot water conditions from the lower Snake and lower Columbia River reservoirs. In 2021, only 4 wild adult sockeye salmon survived and reached their spawning grounds in the Stanley Basin in central Idaho, after struggling past eight dams and warm, stagnant reservoirs downstream.

A note on the ‘Snake River Wild Salmon Returns’ report: The data from this report comes from the Fish Passage Center and Idaho Department of Fish and Game. Tables and graphs were assembled by Idaho Rivers Unitedstaff.

E. Hot Water Impacts

Sockeye salmon with lesions dying from hot water in the Columbia-Snake River Basin ©Conrad Gowell

Given the current returns for wild Snake River Spring/Summer Chinook, steelhead, and sockeye, these fish are much closer to extinction than recovery. Each year, salmon and steelhead are returning far, far below their historical and recovery levels.

The four federal dams and their reservoirs on the lower Snake River continue to be the main obstacle to recovery. The rising temperatures caused by these stagnant reservoirs and reductions in snowpack in recent decades due to climate change are contributing to lower survival and reproductive success for already endangered salmon and steelhead.

Restoring this historic salmon river is essential for protecting these fish from extinction and rebuilding the many benefits they provide for the people of the Northwest and our nation.

View the past Hot Water Report issues here: Hot Water Reports - Compiled

References:
1, 2. Orca Action Month: Exploring the History of Salmon in the Columbia and Snake River Systems
3, 5, 8, 10, 11, 12, 14, 15 The Salmon Community’s View: The status of wild salmon and steelhead populations in the Columbia and Snake River Basin 
4, 9, 13 Idaho Rivers United: Snake River Wild Salmon Returns report
6. Spokesman-Review: Helen Neville: The need to breach the Lower Snake River dams: A look at 2022 fish returns
7. Northwest Sportsman Magazine: Lower Columbia Closing Thursday For Chinook, Steelhead
14. Idaho Fish & Game: Idaho sockeye returns at Lower Granite Dam are already the second-highest in a decade
16. U.S. Environmental Protection Agency Region 10: Columbia River Cold Water Refuges Plan - January 2021

Sockeye salmon with lesions dying from hot water in the Columbia-Snake River Basin ©Conrad Gowell

I. INTRODUCTION

Welcome to the 2023 Hot Water Report: Warming Waters in the Lower Snake and Columbia Rivers.

During the summer, this weekly report provides an update on real-time water temperatures in the lower Snake and Columbia River reservoirs via graphs and analyses, a summary of the highest weekly water temperatures at the forebay/reservoir of each dam, and a monthly status of adult returns for different salmon and steelhead populations as they make their way back to their natal spawning grounds. We’ll report first-hand from scientists, Tribal members, fishing guides, advocates, and other experts about the challenges facing these rivers – and our opportunities to improve and restore them - in order to recover healthy, resilient fish populations and the benefits they deliver to Northwest communities, other fish and wildlife populations (including the critically endangered Southern Resident orca), and ecosystems.

Many once-abundant anadromous fish populations in the Columbia-Snake River Basin are on the brink of extinction today due primarily to harms caused by federal dams and their warming reservoirs. The Columbia-Snake federal hydro-system harms and kills both juvenile and adult fish in multiple ways, including by elevating water temperatures in the summer months in their large, stagnant reservoirs. These cold-water fish begin to suffer harmful effects when water temperatures exceed 68° Fahrenheit.

This week, on the lower Snake River, the reservoir behind the Ice Harbor Dam registered the highest water temperature at 72.01°F – over 4 degrees above the 68°F “harm” threshold. Between 72-73°F water temperatures, salmon migration can stop altogether. Salmon that have stopped or slowed their migration, languish for days or weeks in warm water and begin dying from thermal stress and disease. In Issue 4, we’ll provide insight on how salmon and steelhead declines severely impact the recreational and sportfishing economy and fishing opportunities. Restoring a free-flowing lower Snake River by removing the four dams will advance economic opportunities for sport and recreational salmon industries, restore 140 miles of river for recreation activities, and unlock the major earnings potential of the Snake River Basin. (NOTE: While this HWR issue focuses on recreational fishing, it must be emphasized that salmon also deliver very important economic and cultural benefits for commercial and Tribal fishing communities as well).

A restored, healthy, and resilient lower Snake River is necessary to uphold our nation's promises to Tribes and sustain salmon populations in perpetuity. Dam removal is a huge salmon restoration opportunity as it will reconnect the Northwest’s most emblematic fish to over 5,500 miles of pristine, cold-water river and streams in Idaho, Oregon, and Washington.

The Hot Water Report is a joint project of the Save Our wild Salmon Coalition, American Rivers, Association of Northwest Steelheaders, Columbia Riverkeeper, Earthjustice, Endangered Species Coalition, Environment Oregon, Idaho Conservation League, Idaho Rivers United, Natural Resources Defense Council, National Wildlife Federation, Northwest Sportfishing Industry Association, Orca Network, Sierra Club, Snake River Waterkeeper, Wild Orca and Wild Steelhead Coalition.

II. READING THE DATA - Water Temperatures in the Lower Snake and Columbia Rivers

Figure 1. Lower Snake River Water Temperatures - 2023 Daily Average and 10-year Average. Click on the image to view the graph.

Introduction to the data:
The daily average temperature at the four reservoir forebays (measured with sensors stationed at various depths below the reservoir surface, immediately upstream from the dam) in the lower Snake River (above) and the lower Columbia River (below) for 2023 is represented with solid lines and the 10-year average (2013 - 2023) temperatures with dashed lines of the same color. The dotted line across the graph represents the 68°F “harm threshold” for adult and juvenile fish.

The longer and the higher these temperatures rise above 68°F, the greater the harm, including: migration disruption, increased metabolism, increased susceptibility to disease, reduced reproductive potential (by reducing egg viability), suffocation (warm water carries less dissolved oxygen), and in the worst case - death.

Reservoirs are large, stagnant pools that can absorb enormous amounts of solar radiation, and cause waters to warm. These waters inundate and destroy diverse micro-habitats that healthy rivers support, including cold-water refuges that salmon and steelhead rely upon during their migration. Without these vital pockets of cold water, salmonids cannot rest and recover on their journeys – adults moving upstream to spawn and juveniles moving downstream to the ocean. Rising temperatures and reductions in snowpack in recent decades due to climate change create warmer waters, which results in lower survival and reduced reproductive success for salmon and steelhead.

Figure 2. Lower Columbia River Water Temperatures - 2023 Daily Average and 10-year Average. Click on the image to view the graph.

Discussion of data:
Since April, temperatures in the lower Snake River and the lower Columbia River reservoirs have steadily increased. As Figure 1 shows, this week, the reservoir behind the Ice Harbor Dam had the highest average temperature of 71.99°F from July 19 - July 25. The Lower Monumental reservoir had the second highest average temperature of 70.53°F on July 23.

As Figure 2 shows, this week, the reservoir behind the Bonneville Dam, and The Dalles Dam registered the highest average temperature of 72.5°F. Both juvenile and adult salmon are now experiencing water temperatures above the 68°F “harm” threshold in several of the reservoirs they pass.

Below, we present the weekly high temperatures for each reservoir on the lower Snake and Columbia rivers for July 19 - 25

A note on the data: The 2023 lower Snake River and lower Columbia River water temperature data presented in the Hot Water Report are collected from the Columbia River DART program by Columbia Basin Research, University of Washington, using data courtesy of the U.S. Army Corps of Engineers (USACE). The 10-year average water temperature data is courtesy of the Fish Passage Center. There is no data available for the Lower Monumental 10-year average water temperature, and McNary reservoir water temperature data is collected from USACE with current available data. Graphs and tables were assembled by SOS Staff.

 III. WEEKLY HIGH WATER TEMPERATURES: July 19 - July 25

This week, on the lower Snake River, the reservoir behind the Ice Harbor Dam registered the highest water temperature at 72.01°F on July 22, and the Lower Monumental Dam registered the second highest temperature at 70.99°F on July 23.

This week, on the lower Columbia River, the Bonneville reservoir and The Dalles reservoir registered the highest water temperature at 72.86°F.

IV. How Snake River salmon declines impact the Northwest recreational fishing economy

Not long ago, the Columbia-Snake Basin supported the most diverse and abundant salmon and steelhead populations in the continental United States. Historically, an estimated 10-16 million wild salmon and steelhead annually entered the Columbia River Basin to spawn, with 2-4 million Spring/Summer Chinook and B-run steelhead utilizing the Snake River watershed.

Salmon are not only vital to Pacific Northwest ecology, culture, and food but also contribute to a thriving fishing economy. However, since the completion of the four lower Snake River dams in the 1970s, annual returns for salmon and steelhead have persisted far below the recovery goals necessary to remove them from the protections of the Endangered Species Act (ESA), and the dams continue to threaten the existing regional fishing economy. With devastating and record-low salmon and steelhead returns, fishing businesses and communities suffer due to the loss of economic opportunities these fish would otherwise provide.

“There's no longer such a thing as a full-time fishing guide. We don't get to make a full-time living at this any longer like I did 20 years ago. Snake River salmon and steelhead are keystone species and iconic species of the Pacific Northwest, drawing visitors from all over the world because those populations are decimated on the East Coast and in Europe. The West Coast is the last remaining stronghold of wild salmon and steelhead.”

– Bob Rees, recreational fishing guide and executive director for the Northwest Guides and Anglers Association

Restoring a free-flowing Snake River through the removal of its four dams is our only feasible option to rebuild salmon and steelhead abundance. It will generate hundreds of millions of dollars annually from restored fishing opportunities in many rural communities and rebuild a robust and prosperous salmon economy.

Loss of economic opportunities for Recreational Fishing and Sportfishing in the Northwest

Snake River salmon and steelhead populations support thousands of ocean, sportfishing and guide jobs in often-rural communities throughout the Northwest. Recreational fishing for salmon and steelhead in the Columbia and Snake River Basin currently supports a vital economy in the Northwest. Recreational fishing involves spending on boats and related fishing gear (rods, reels, tackle, etc.), as well as travel expenses (food, gas, lodging, etc.) in and around river and coastal communities. This economic output ripples through local communities, helping to foster jobs, economic stability, and growth.

The American Sportfishing Association’s ‘Economic Contribution of Recreational Fishing’ report shows the number of jobs that are dependent on salmon and steelhead (Table 1). In combining the number of recreational fishing jobs in Washington, Oregon, and Idaho, salmon and steelhead are key in sustaining over 29,420 jobs and have a positive economic influence in the Northwest.

Increasingly, recreational and sportfishing businesses are faced with emergency closures and a limited number of days to fish in order to protect ESA-listed salmon and steelhead. A majority of recreational and sportfishing jobs have been negatively impacted by the decline of salmon and steelhead and loss of economic opportunity. Communities who benefit from salmon also suffer economically, culturally, and socially; such as hotels, restaurants, shops, and other businesses that rely on fishing.

"I made a choice to stop guiding due to decreased run size of steelhead populations. Seasons closed, businesses slowed, and my livelihood suffered. But more than anything, I felt guilty harassing a population that was already so depressed.

The main issue, however, is not my guiding or fishing. The main issue is that salmon and steelhead need rivers. The dams have reduced the Snake to a series of lakes."

– Ian Faurot, McCall, ID

The lower Snake River dams and their hot water reservoirs create hazardous conditions for salmon and steelhead as they migrate. The dams and reservoirs on the lower Snake River continue to be the main obstacle to recovery for salmon and steelhead. In 2015, some of the earliest and hottest weather on record produced warm river temperatures that killed more than 95% of all adult sockeye salmon returning to the Columbia Basin. In recent years, state agencies have had to severely limit or cancel entire fishing seasons to protect the dwindling fish headed for the Snake Basin.

In 2019, anglers only had about seven days of a meaningful opportunity for salmon in the first seven months on the Columbia and Snake rivers. It was a record low of economic benefit to communities over the last 16 years, and 2020 produced equally poor opportunities.

In 2021, regional fish and wildlife agencies recorded one of the smallest counts of adult spring Chinook salmon in a generation in the Snake and Columbia River Basin, and Snake River steelhead saw the lowest returns in history, forcing emergency fishing closures in Washington and Oregon.

This year, due to early snowmelt, lack of spring rain and low streamflows, hot water temperatures in the lower Snake River, salmon and steelhead are overwhelmed by the tortuous conditions created by these federal dams and their warming reservoirs, thus imperiling their final journeys to their natal spawning grounds. This week, the Ice Harbor reservoir reached the highest water we have seen so far this year at 72.01°F – over 4 degrees over the 68°F “harm” threshold. Between 72-73°F water temperatures, salmon migration stops altogether or is slowed. Salmon can languish for days or weeks in hot water and begin to die from thermal stress and disease.

"During my relatively short time guiding, I have seen a steep decline in yearly averages to the point of full river closures up and down the Columbia corridor. So much so that I have lost full seasons and opportunities due to low steelhead returns and morally feeling unethical to target such a struggling fish."

– KynsLee Scott, fly-fishing guide, Missoula, MT

A letter signed by hundreds of businesses and individuals in the Pacific Northwest who depend upon robust fisheries, outdoor recreation and healthy rivers, recently urged immediate action from the Biden Administration to ensure the fishery resources that industries, Northwest Tribes, and imperiled Southern Resident Orcas depend upon are restored to abundance. 

The letter states “dam removal must be a ‘centerpiece action’ for a durable long-term solution to salmon recovery in the Snake River Basin, and investments must be identified and prioritized to ensure economic development opportunities for the recreation, tourism, and fishing industries that rely on abundant salmon and steelhead populations, and healthy free-flowing rivers. By restoring the lower Snake River and replacing their services, we will regain 140 miles of riverfront on each side of the river to fish, hunt and recreate while also modernizing and expanding agriculture, transportation and clean energy infrastructure in the Columbia Basin.”

Opportunities for anglers have declined drastically in recent years, which keeps families from recreating outside together and the sportfishing community from importing critical revenue to rural communities during shoulder tourist seasons. The benefit of economic opportunities for recreational fishing would increase when the dams are breached, and an increase in harvestable salmon abundance will follow.

Restoring a free-flowing lower Snake River

“I look forward to the day where I can share the joy of fishing for salmon and steelhead with my guests, and that day will come as soon as we breach the four lower Snake River dams and replace the services they provide. I don't think that we should look at the removal of the four lower Snake River dams as an expense but rather an investment in the economy and the ecology of the area.” 

– Mandela van Eeden, Communications Coordinator for the National Wildlife Federation Outdoors; Artemis sportswoman; and part-time fishing guide and river guide

Restoring a free-flowing lower Snake River by removing the four dams will advance economic opportunities for sport and recreational salmon industries, restore 140 miles of river for recreation activities, and unlock the major earnings potential in the Snake River Basin.

Notably, Senator Murray and Governor Inslee’s final Lower Snake River Dams: Benefit Replacement Report recognized that with a free-flowing lower Snake River and restored salmon fisheries in the Columbia-Snake Basin, recreational fishing (a major economic driver of rural communities) could generate up to $1 billion annually in additional regional personal income benefits and support up to 25,000 new family-wage jobs.

A restored lower Snake River will create abundant fishing opportunities, new network of waterfront parks and trails for hiking, biking, hunting, fishing, and other recreation. It will also draw visitors from across the nation and world to see thriving salmon and steelhead. Interest in the restored river will generate diverse recreation-based economic activity, especially in inland Northwest communities like Lewiston, Idaho and Pasco, Washington.

Removing the four lower Snake River dams and replacing their services is our only viable long-term solution to Snake River salmon and steelhead recovery and our only opportunity to secure economic development opportunities for recreation and sportfishing that heavily rely on abundant salmon and steelhead populations.

“Salmon fishing supports thousands of jobs and is an important part of our Northwest way of life. But fishing businesses are struggling for survival today, and the rock bottom runs and fishing closures have been devastating.We need all of our elected leaders leaning in and working on real solutions.”

– Liz Hamilton, executive director for the Northwest Sportfishing Industry Association 

V. Read ‘Economic development for rural communities and recovery for imperiled salmon’ op-ed by Dan McDonald, president and board chairman of the Yakima Bait Company, based in Granger, Washington.

“Restoring a free-flowing lower Snake River – and replacing the dams’ services with alternatives – is critical for protecting its fish from extinction. It also represents our region’s greatest opportunity to safeguard Washington’s recreational fishing industry that supports almost 15,000 jobs and an annual economic output of $2.3 billion every year.

This kind of comprehensive approach – removing these dams and replacing their services – also represents the greatest economic development opportunity our region has seen in decades. With bi-partisan leadership in the Northwest and an administration in Washington D.C. that’s committed to expanding clean energy resources and modernizing other critical infrastructure, we have a once-in-a-generation opportunity right now to fix some big problems and modernize aging infrastructure.”

Read the full op-ed here.

VI.  LINKS TO RECENT NEWS

1. View the past Hot Water Report issues here: Hot Water Reports - Compiled
2. The Lewiston Tribune: Sockeye begin epic Northwest journey (July 22, 2023)
3. East Oregonian: Other views: The science is clear on restoring wild salmon in the Snake River Basin (July 22, 2023)
4. Idaho Capital Sun: Salmon politics in motion: Responsible momentum is building in Idaho, Pacific Northwest(July 27, 2023)

Sockeye salmon with lesions dying from hot water in the Columbia-Snake River Basin ©Conrad Gowell

I. INTRODUCTION

Welcome to the 2023 Hot Water Report: Warming Waters in the lower Snake and Columbia rivers.

During the summer, this weekly report provides an update on real-time water temperatures in the lower Snake and Columbia river reservoirs via graphs and analyses, a summary of the highest weekly water temperatures at the forebay/reservoir of each dam, and a monthly status of adult returns for different salmon and steelhead populations as they make their way back to their natal spawning grounds. We’ll report first-hand from scientists, Tribal members, fishing guides, advocates, and other experts about the challenges facing these rivers - and our opportunities to improve and restore them - in order to recover healthy, resilient fish populations and the benefits they deliver to Northwest communities, other fish and wildlife populations (including the critically endangered Southern Resident orca), and ecosystems.

The once-abundant anadromous fish populations of the Columbia-Snake River Basin are on the brink of extinction today due primarily to harms caused by federal dams and their warming reservoirs. The Columbia-Snake federal hydro-system harms and kills both juvenile and adult fish in multiple ways, including by elevating water temperatures in the summer months in their large, stagnant reservoirs. These cold-water fish begin to suffer harmful effects when water temperatures exceed 68° Fahrenheit.

Today, harmful hot water episodes above 68°F in the lower Snake and Columbia rivers are increasing in duration, frequency, and intensity. Our anthropogenically changing climate is worsening these harmful impacts on salmon survival and increasing the urgency to take action to maintain cool water temperatures - or we will lose these species forever. Recovering abundant salmon populations by restoring a free-flowing lower Snake River through dam removal is a once-in-a-lifetime opportunity for the Northwest and nation; and our only feasible option to address hot water temperatures created by the four lower Snake River dams.

A restored, healthy, and resilient lower Snake River is necessary to uphold our nation's promises to Tribes and sustain salmon populations in perpetuity. Dam removal will reconnect the Northwest’s most emblematic fish to over 5,500 miles of pristine, cold-water river and streams in Idaho, Oregon, and Washington.

The Hot Water Report is a joint project of the Save Our wild Salmon Coalition, Association of Northwest Steelheaders, Columbia Riverkeeper, Earthjustice, Endangered Species Coalition, Environment Oregon, Idaho Conservation League, Idaho Rivers United, Natural Resources Defense Council, National Wildlife Federation, Northwest Sportfishing Industry Association, Orca Network, Sierra Club, Snake River Waterkeeper, Wild Orca and Wild Steelhead Coalition.

II. READING THE DATA - Lower Snake and Columbia River Temperatures

Click on the image to view the graph. 

Introduction: The daily average temperature at the four reservoir forebays (immediately upstream from the dam) in the lower Snake River (above) and the lower Columbia River (below) for 2023 is represented with solid lines and the 10-year average (2013 - 2023) temperatures with dashed lines of the same color. The dotted line across the graph represents the 68°F “harm threshold” for adult and juvenile fish.

The longer and the higher these temperatures rise above 68°F, the greater the harm, including: migration disruption, increased metabolism, increased susceptibility to disease, reduced reproductive potential (by reducing egg viability), suffocation (warm water carries less oxygen), and in worst case - death.

Reservoirs are large, slow-moving pools which absorb enormous amounts of solar radiation, causing warm waters. These waters inundate and destroy diverse micro-habitats that healthy rivers support, including cold-water refuges that salmon and steelhead rely upon during summer migrations. Without these vital pockets of cold water, salmonids cannot rest and recover on their journeys – adults moving upstream to spawn and juveniles moving downstream to the ocean. Rising temperatures and reductions in snowpack in recent decades due to climate change have resulted in warmer waters, which results in lower survival and reduced reproductive success for salmon and steelhead. The lower Snake River dams exacerbate these already warmed waters, creating conditions that harm these fish.

Click on the image to view the graph. 

Discussion of data: Since April, temperatures in the lower Snake River and the lower Columbia River reservoirs have steadily increased. Water temperatures in June this year are considerably higher than 10-year average. This week, the reservoir behind the Lower Granite Dam had the highest recorded average temperature of 68.63°F on July 5. Similarly, Little Goose reservoir had the second highest recorded average temperature of 68.49°F on July 5. 

On the lower Columbia River, the reservoir behind the John Day dam had the highest recorded average temperature of 69.98°F on July 5. Both juvenile and adult salmon are now experiencing water temperatures above the 68°F in several of the stagnant reservoirs they migrate through. 

Below, we present the highest temperatures for each reservoir on the lower Snake and Columbia rivers for June 28 - July 5.

 III. WEEKLY HIGH TEMPERATURES: 6/28 - 7/5

On the lower Snake River, the reservoir behind the Lower Granite Dam registered the highest water temperature at 68.67°F on July 4, and the Little Goose reservoir had the second highest temperature at 68.49°F on July 5.On the lower Columbia River, the John Day reservoir registered the highest water temperature at 70.88°F on July 5.

A note on the data: The 2023 lower Snake River and lower Columbia River water temperature data presented in the Hot Water Report are collected from the Columbia River DART program by Columbia Basin Research, University of Washington, using data courtesy of the U.S. Army Corps of Engineers (USACE). The 10-year average water temperature data is courtesy of the Fish Passage Center. There is no data available for the Lower Monumental 10-year average water temperature, and McNary reservoir water temperature data is collected from USACE with current available data. Graphs and tables were assembled by SOS Staff.

IV. Salmon and Steelhead’s Role in NW Biodiversity

For millennia, wild Snake and Columbia River salmon and steelhead have delivered vast cultural, economic, nutritional, and ecological benefits to the people, fish, and wildlife of the Northwest. Prior to the dam construction, the pristine, clear, cold waters of the Snake River Basin were home to millions of adult salmon and steelhead.¹ Each year, they would return from the Pacific Ocean, swimming against the current in search of their natal spawning gravels, and deliver many millions of pounds of high-quality marine-derived nutrients to the landscape and wildlife of the Northwest.

Before the dams - when these rivers flowed freely - juvenile salmon and steelhead took as few as five days to complete their migration to the ocean. Today, however, the dams and reservoirs have stilled the current, and salmon now require a month or more to reach the ocean.² Wild fish return as adults at just 1-3 percent of historic levels. Many of the Columbia-Snake River Basin salmon runs have been locally extirpated. Thirteen populations, including all four Snake River populations, are listed as threatened or endangered under the Endangered Species Act and remain at risk for extinction.

Salmon Ecology

Art Imitates Life ©Amy Gulick/amygulick.com

The ecological significance of salmon is magnificently multifaceted. Salmon and steelhead are a critical nutrient link between oceans, rivers, streams, forests, and wildlife. Salmon runs function as enormous pumps that provide vast amounts of marine nutrients from the ocean to river systems.³ Over 137 species benefit from and utilize the ocean-origin nutrients that salmon and steelhead deliver.⁴ Because of their vast ecological impact, salmon are considered a keystone, connector, and indicator species. In other words, salmon have unique and substantial effects on their own and neighboring environments such that no other species can replace its particular ecological role. When keystone species are removed, the entire ecosystem typically collapses.

The state of salmon populations reflect the overall health of the ecosystem as a whole. When salmon populations are in peril, it indicates that the entire ecosystem is unhealthy and/or under stress.

Due to the elevated water temperatures in the stagnant reservoirs and other harms caused by the lower Snake River dams, salmon runs have been in steep decline for several decades. These population declines have dramatically reduced the amount of vital nutrients transferred annually from the ocean to freshwater ecosystems, and surrounding riparian habitat. Restoring wild salmon and steelhead will strengthen this ancient connection between saltwater, freshwater, and watersheds and help to restore former productivity, and increase the overall biodiversity ecosystem across the basin and in Northwest coastal waters.

Interdependence between people, rivers, and salmon

Scaffold fishing at Celilo Joe Palmer fishing from a hanging scaffold on Standing Island. Aug 1952. ©Columbia River Inter-Tribal Fish Commission/Raymond Mathen

Salmon are not only ecologically significant – they are also profoundly fundamental to Northwest Tribes’ spiritual and cultural identity, economic prosperity, and food system sovereignty since time immemorial.⁵

“The importance of the first salmon ceremony has to do with the celebration of life, of the salmon as subsistence, meaning that the Indians depend upon the salmon for their living. And the annual celebration is just that – it’s an appreciation that the salmon are coming back. It is again the natural law; the cycle of life. It’s the way things are and if there was no water, there would be no salmon, there would be no cycle, no food. And the Indian people respect it accordingly.” —Antone Minthorn, Umatilla⁶

Since time immemorial, Northwest Tribes have stewarded and harvested salmon in the Snake River Basin. Recently, the Affiliated Tribes of Northwest Indians and the National Congress of American Indians passed resolutions calling for the removal of the lower Snake River dams and “actions that will be needed for salmon and river restoration in the Columbia Basin: to support salmon, steelhead, lamprey, and native fish, within their complete ecosystems – from the orca in the ocean and Puget Sound to the nutrients salmon supply to the furthest inland streams – and to support the Northwest [Tribal] people who have lived with these species in mutual dependence since time immemorial.”⁷

Salmon and steelhead migration tells the tale of an exceptional species, yet their significance is not merely a story of ecological awe. These fish also exemplify the reciprocal relationships between people and planet. At this moment, we have an urgent opportunity to restore ecosystem health across the basin and recover salmon and steelhead to abundance by removing the four lower Snake River dams and replacing the dams’ services. For additional information, please visit wildsalmon.org.

References:
1. Columbia River Inter-Tribal Fish Commission: Columbia River Fish Species. 
2. Spokesman-Review: Environmentalists, politicians clash over...hearing to defend Snake River dams (June 28, 2023)
3. Wild Salmon Center: Why protect Salmon. 
4. The National Wildlife Federation: Chinook Salmon.
5,6. Columbia River Inter-Tribal Fish Commission: Tribal Salmon Culture. 
7. Affiliated Tribes of Northwest Indians (ATNI): Resolutions # 2022 - 23 Supporting and thanking all the Leaders who have Heard the ATNI Tribes’ Voices, and Especially the Biden-Harris Administration, and Senator Murray and Governor Inslee, for Steps they are taking toward Salmon and River Restoration in the Pacific Northwest, and toward Long-Ignored Tribal Justice for our Peoples and Homelands 

 LINKS TO RECENT NEWS:

1. The Seattle Times: As the West’s dam removal movement presses on, could the Lower Snake be next? (June 14, 2023)

2. Seattle Times Opinion: Salmon restoration is a matter of ecological, cultural survival by Sen. Claudia Kauffman D-Kent (June 14, 2023)

3. Spokesman-Review Guest Opinion: Four Tribal chairs: We need a Columbia Basin Initiative for salmon, tribes and energy by Gerald Lewis, Kat Brigham, Jonathan W. Smith, Sr. and Shannon F. Wheeler (June 4, 2023)

4. Everett Herald Opinion: Sen. Cantwell should join effort to retire Snake dams (May 26, 2023)

5. Public News Service: Historic Step Forward for Snake River Dam Replacement in WA Budget (May 18, 2023)

Sockeye salmon with lesions dying from hot water in the Columbia-Snake River Basin ©Conrad Gowell

I. INTRODUCTION

Welcome to the 2023 Hot Water Report: Warming Waters in the Lower Snake and Columbia Rivers.

During the summer, this weekly report provides an update on real-time water temperatures in the lower Snake and Columbia River reservoirs via graphs and analyses, a summary of the highest weekly water temperatures at the forebay/reservoir of each federal dam, and a monthly status of adult returns for different salmon and steelhead populations as they make their way back to their natal spawning grounds. We’ll report first-hand from scientists, Tribal members, fishing guides, advocates, and other experts about the challenges facing these rivers – and our opportunities to improve and restore them - in order to recover healthy, resilient fish populations and the benefits they deliver to Northwest communities, other fish and wildlife populations (including the critically endangered Southern Resident orca), and ecosystems.

Many once-abundant anadromous fish populations—fish that hatch in freshwater, go to sea, and return to freshwater to spawn—in the Columbia-Snake River Basin are on the brink of extinction today due primarily to harms caused by federal dams and their warming reservoirs. The Columbia-Snake federal hydro-system harms and kills both juvenile and adult fish in multiple ways, including by elevating water temperatures in the summer months in their large, stagnant reservoirs. These cold-water fish begin to suffer harmful effects when water temperatures exceed 68° Fahrenheit.

This week, on the lower Snake River, the reservoir behind the Ice Harbor Dam registered the highest water temperature at 71.10°F on August 24. Both juvenile and adult salmon continue to experience water temperatures well above the 68°F 'harm threshold' for over 50 days. For Issue 9, we discuss this summer's adult returns for Snake River sockeye salmon. Unfortunately, hot water has prevented almost an entire generation of critically endangered Snake River sockeye from reaching their spawning grounds in Idaho. This year, just 24 natural-origin sockeye have been able to navigate through the lower Snake River dams and up to Idaho’s Stanley Basin to spawn. Sockeye salmon are nowhere near their recovery goals. Delisting from the Endangered Species Act requires an annual return of 2,500 natural-origin adult sockeye. For the Columbia Basin Partnership, 15,750 natural annual spawners are needed to meet the partnership's "medium" range abundance goals.

Restoring a free-flowing Snake River by removing its four dams (and replacing their services) is essential to provide cold, clean, healthy water for salmon and steelhead, to protect and recover these once-highly prolific fish from extinction, to uphold our nation's treaty commitments to Tribes, and to help feed critically endangered Southern Residents and other fish and wildlife species.

View the past Hot Water Report issues here: Hot Water Reports - Compiled

The Hot Water Report is a joint project of the Save Our wild Salmon Coalition, American Rivers, Association of Northwest Steelheaders, Columbia Riverkeeper, Earthjustice, Endangered Species Coalition, Environment Oregon, Idaho Conservation League, Idaho Rivers United, Natural Resources Defense Council, National Wildlife Federation, Northwest Sportfishing Industry Association, Orca Network, Sierra Club, Snake River Waterkeeper, Wild Orca and Wild Steelhead Coalition.

II. READING THE DATA - Water Temperatures in the Lower Snake and Columbia Rivers

Figure 1. Lower Snake River Water Temperatures - 2023 Daily Average and 10-year Average. Click on the image to view the graph.

Introduction to the data:
The daily average temperature at the four reservoir forebays (measured with sensors stationed at various depths below the reservoir surface, immediately upstream from the dam) in the lower Snake River (above) and the lower Columbia River (below) for 2023 is represented with solid lines and the 10-year average (2013 - 2023) temperatures with dashed lines of the same color. The dotted line across the graph represents the 68°F “harm threshold” for adult and juvenile fish.

The longer and the higher these temperatures rise above 68°F, the greater the harm, including: migration disruption, increased metabolism, increased susceptibility to disease, reduced reproductive potential (by reducing egg viability), suffocation (warm water carries less dissolved oxygen), and in the worst case - death.

The four reservoirs on the lower Snake River are large, stagnant pools that absorb enormous amounts of solar radiation that cause the water to warm. These waters inundate and destroy diverse micro-habitats that healthy rivers support, including cold-water refuges that salmon and steelhead rely upon during their migration. Without these vital pockets of cold water, salmonids cannot rest and recover on their journeys—adults moving upstream to spawn and juveniles moving downstream to the ocean. Rising temperatures and reductions in snowpack in recent decades due to climate change create warmer waters, which results in lower survival and reduced reproductive success for salmon and steelhead.

Figure 2. Lower Columbia River Water Temperatures - 2023 Daily Average and 10-year Average. Click on the image to view the graph.

Discussion of data:
Since April, temperatures in the lower Snake River and the lower Columbia River reservoirs have steadily increased. As Figure 1 shows, the reservoir behind the Ice Harbor Dam had the highest daily average temperature of 70.77°F on August 30 and August 31. The Lower Monumental reservoir had the second highest daily average temperature of 70.53°F on August 25.

As Figure 2 shows, the reservoir behind the John Day Dam registered the highest average temperature of 72.32°F on August 25. Both juvenile and adult salmon continue to experience water temperatures well above the 68°F 'harm threshold' for over 50 days.

Below, we present the weekly high water temperatures for each reservoir on the lower Snake and Columbia rivers for August 24 - August 31.

A note on the data: The 2023 lower Snake River and lower Columbia River water temperature data presented in the Hot Water Report are collected from the Columbia River DART program by Columbia Basin Research, University of Washington, using data courtesy of the U.S. Army Corps of Engineers (USACE). The 10-year average water temperature data is courtesy of the Fish Passage Center. There is no data available for the Lower Monumental 10-year average water temperature, and McNary reservoir hourly water temperature data is collected from USACE with current available data. Graphs and tables were assembled by SOS Staff.

III. WEEKLY HIGH WATER TEMPERATURES: August 24 - August 31

This week, on the lower Snake River, the reservoir behind the Ice Harbor Dam registered the highest water temperature at 71.10°F on August 24, and the Lower Monumental Dam registered the second highest temperature at 70.92°F on August 25.

This week, on the lower Columbia River, the John Day reservoir registered the highest water temperature at 73.04°F on August 27.

IV. ​​Hot water kills most Snake River sockeye. Again.
By Miles Johnson, Legal Director for Columbia Riverkeeper.

What began as a promising run of endangered Snake River sockeye has ended in disaster. Again. This year, roughly 80% of the adult Snake River sockeye died prematurely in the reservoirs of the lower Columbia and lower Snake rivers. Hot water in these reservoirs prevented almost an entire generation of critically endangered fish from reaching their spawning gravels in Idaho—violating the Endangered Species Act and dealing another blow to the Shoshone-Bannock Tribes’ long-running effort to recover this unique and culturally important species.

Sadly, mass die-offs of endangered Snake River sockeye caused by hot water in the lower Columbia and Snake reservoirs are now common. In 2015, 96% of Snake River sockeye succumbed to hot water in the reservoirs. In 2021, 70% died when the rivers became too hot. Even in “good” years, hot water in the reservoirs kills a quarter of the breeding population of this endangered species.

Sockeye salmon with lesions dying from hot water in the Columbia-Snake River Basin ©Conrad Gowell

This dire situation underscores the need to improve the freshwater habitat that Columbia and Snake river salmon and steelhead depend on. Especially for Snake River fish that must pass eight dams and reservoirs to reach the ocean—and then those same eight dams and reservoirs to return to their natal streams to spawn—the federal hydro-system is the single largest source of mortality. Roughly half of all juvenile Snake River sockeye do not survive their downstream migration through the eight dams. Adult Snake River sockeye are often killed at similar or greater rates upon their return.

Sockeye salmon need cool water to survive, but they migrate upstream during the middle of the summer when reservoir temperatures begin to rise. As shown above and in previous Hot Water Reports, the Columbia and lower Snake reservoirs now routinely top 70°F for much of the summer. That’s a problem because adult salmon have difficulty migrating upstream when water temperatures approach 68°F. Migration stops altogether when water temperatures reach 72 to 73°F. Salmon that have stopped or slowed their migration, and languish for days or weeks in warm water, begin dying from stress and disease. Warm main-stem rivers that are dominated by reservoirs—like the Columbia and lower Snake—are especially dangerous to adult sockeye.

Given the risks from hot water, it’s no wonder that the National Marine Fisheries Service recently said that Snake River sockeye salmon are “at a high risk of extinction.” This year, just 24 wild sockeye were able to navigate through the lower Snake River dams and up to Idaho’s Stanley Basin to spawn. To get off the Endangered Species List, wild sockeye numbers would need to reach 2,500 wild adult fish. And the Columbia Basin Partnership has set a “medium” abundance goal of 15,750 wild spawners. Without big improvements in water quality, federal scientists predict that adult Snake River sockeye survival will further decline by 80% in coming years, likely resulting in extinction.

Un-damming the lower Snake River would not solve every water temperature problem in the Columbia River Basin. But un-damming the lower Snake would keep this 140-mile section of river cool enough for endangered sockeye, as well as reduce the cumulative stress that many sockeye succumb to upstream of the lower Snake.

V. Four Tribal Chairs: We need a Columbia Basin Initiative for salmon, tribes and energy
By Gerald Lewis, Kat Brigham, Jonathan W. Smith, Sr. and Shannon F. Wheeler

June 4, 2023

For our people to survive, we need salmon. Without salmon, there can be no Salmon People. We have a sacred relationship with – and obligation to – the salmon populations that call Nch’í Wána (Columbia River) home.

For nearly 100 years, Columbia and Snake River dams have been built and then operated – to this day and every day – on tribal homelands. The dams became a foundation of the modern Northwest economy. But that has come at an unjust price for Tribal Nations. Our peoples’ homes were flooded, our sacred sites destroyed, and the value of our lands and waters continues to be extracted in a manner that negatively impacts our natural resources. Salmon, our First Food, have been decimated.

Despite decades of dedicated restoration effort, salmon populations in the Columbia River Basin are on the brink of extinction.

This point of no return threatens salmon themselves, and our way of life. It violates the treaties our Nations hold with the United States.

This status quo is untenable. To avoid extinction, we must act now.

We urgently need a comprehensive Columbia Basin Restoration Initiative that restores salmon and other native fish populations to healthy and abundant levels; honors federal commitments to Tribal Nations; and delivers affordable, clean power.

Three key actions are necessary now to restore fish to healthy and harvestable levels for all.

First, fully fund habitat restoration work throughout the Columbia River Basin.

Second, replace the benefits of the four lower Snake River dams to enable breaching to restore the migration corridor to the best remaining salmon habitat in the lower United States.

Third, salmon must be returned to their native habitat in the upper Columbia River.

All three actions are “essential” to salmon recovery, as the National Oceanic and Atmospheric Administration has confirmed.

Read the full Spokesman-Review Guest Opinion by the Four Tribal Chairs.

Gerald Lewis is Chairman of the Tribal Council of Yakama Nation.
Kat Brigham is Chair of the board of trustees of the Confederated Tribes of the Umatilla Indian Reservation.
Jonathan W. Smith, Sr. is Chairman of the Tribal Council of the Confederated Tribes of the Warm Springs Reservation of Oregon.
Shannon F. Wheeler is Chairman of the Tribal Executive Committee of the Nez Perce Tribe.

Sockeye salmon with lesions dying from hot water in the Columbia-Snake River Basin ©Conrad Gowell

I. INTRODUCTION

Welcome to the 2023 Hot Water Report: Warming Waters in the Lower Snake and Columbia Rivers, our final issue for this summer.

For millennia, wild Snake and Columbia River salmon and steelhead have delivered vast cultural, economic, nutritional, and ecological benefits to the people, fish, and wildlife of the Northwest. Prior to the construction of the lower Snake River dams, the pristine, clear, cold waters of the Snake River Basin were home to millions of adult salmon and steelhead. Each year, they would return from the Pacific Ocean, swimming against the current in search of their natal spawning gravels, and deliver many millions of pounds of high-quality marine-derived nutrients to the landscape and wildlife of the Northwest.

These once-abundant anadromous fish populations—fish that hatch in freshwater, go to sea, and return to freshwater to spawn—in the Columbia-Snake River Basin are on the brink of extinction today due primarily to harms caused by federal dams and their warming reservoirs. Thirteen populations, including all four Snake River populations, are listed as threatened or endangered under the Endangered Species Act and at grave risk of extinction. The lower Snake River’s dams and reservoirs harm and kill both juvenile and adult fish in multiple ways, including by elevating water temperatures in the summer months in their large, stagnant reservoirs. These cold-water fish begin to suffer harmful effects when water temperatures exceed 68° Fahrenheit.

In this final Hot Water Report issue, we summarize this year’s high water temperatures in the lower Snake and Columbia reservoirs, the number of days each of the reservoirs exceeded 68°F, and review the current return status for Snake River salmon and steelhead in comparison to their recovery goals. Given the current returns for wild Snake River Spring/Summer Chinook, steelhead, and sockeye, these fish are far closer to extinction than recovery. Wild fish return as adults today at just 1-2% of historic levels and each year salmon and steelhead are returning far, far below their historic and recovery levels.

The four federal dams and their reservoirs on the lower Snake River are the primary factor preventing salmon from reaching spawning grounds and reproducing in viable numbers. Restoring a free-flowing Snake River by removing its four dams and replacing their services is essential to provide cold, clean, healthy water for salmon and steelhead, protect and recover these once-highly prolific fish populations, uphold our nation's promises to Tribes, and help feed the critically endangered Southern Resident orcas and other fish and wildlife species.

View the past Hot Water Report issues here: Hot Water Reports - Compiled

The Hot Water Report is a joint project of the Save Our wild Salmon Coalition, American Rivers, Association of Northwest Steelheaders, Columbia Riverkeeper, Earthjustice, Endangered Species Coalition, Environment Oregon, Idaho Conservation League, Idaho Rivers United, Natural Resources Defense Council, National Wildlife Federation, Northwest Sportfishing Industry Association, Orca Network, Sierra Club, Snake River Waterkeeper, Wild Orca and Wild Steelhead Coalition.

II. READING THE DATA - Highest Water Temperatures in the Lower Snake and Columbia Rivers from April 1 - September 7, 2023.

Introduction to the data:
From April 1 - September 7, 2023, we recorded water temperatures at the four reservoir forebays (measured with sensors stationed at various depths below the reservoir surface, immediately upstream from the dam) in the lower Snake River and the lower Columbia River. In the following tables (Table 1 and Table 2), we present a summary of the highest water temperatures in 2023, the date of the highest temperatures, and the number of days each of the reservoirs reached above the 68°F “harm” threshold.

The longer and the higher temperatures rise above 68°F (this threshold is the legal and biological limit scientists identify to protect salmon), the greater the harm, including: migration disruption, increased metabolism, increased susceptibility to disease, reduced reproductive potential (by reducing egg viability), suffocation (warm water carries less dissolved oxygen), and in the worst case - death.

Table 1: Highest water temperatures in the lower Snake River in 2023.

Discussion of data:
This year, salmon and steelhead experienced another summer of hot, harmful water temperatures in the lower Snake River and the lower Columbia River. From early July to September, all four lower Snake River reservoirs had water temperatures above 68°F.

• Hot water temperatures on the lower Snake River (Table 1): On August 19, 2023, the reservoir behind the Ice Harbor Dam registered the highest temperature recorded this summer – 72.73°F more than 4 degrees above the 68°F “harm” threshold. The Ice Harbor reservoir registered above 68°F for 62 days. Both Lower Monumental and Little Goose reservoirs registered above 68°F for 60 days.
  • Salmon in hot water: Adult and juvenile salmon have difficulty migrating when water temperatures exceed 68°F. Migration stops altogether when water temperatures reach 72-73°F. Salmon that have stopped or slowed their migration can languish for days or weeks in warm water and begin to die from thermal stress and disease.
  • Lower Granite reservoir: The Lower Granite reservoir was the first reservoir to reach 68°F. This summer, the reservoir registered a high temperature of 71.20°F on August 22, 2023. Lower Granite reservoir registered above 68°F for 32 days, fewer days compared to the other reservoirs. This distinction is the result of the US Army Corps of Engineers' annual release of cold water from the Dworshak reservoir into the Clearwater River, a tributary to the lower Snake River. The goal of this release is to lower water temperatures and aid salmon and steelhead survival, but the benefit of this cold water does not last long in the heat of the summer and does not cool the other three downstream reservoirs on the lower Snake. According to scientists and modelers at the Environmental Protection Agency (USEPA), with lower Snake River dam removal, the additional benefit of cold water released from the Dworshak reservoir will extend all the way down the lower Snake River to its confluence with the Columbia River in south-central Washington State.

Table 2: Highest water temperatures in the lower Columbia River in 2023.

Hot water temperatures on the lower Columbia River (Table 2):

• On August 16, 2023, the reservoir behind the Bonneville Dam registered the highest temperature recorded this summer – 73.58°F over 5 degrees above the 68°F threshold.

• The water temperatures in the four reservoirs created by dams on the lower Columbia River give us an in-depth look at the lethal conditions and temperatures that many Columbia Basin salmon and steelhead must now migrate through in the summer months. Endangered Snake River fish must traverse a total of eight stagnant reservoirs on their migration to the ocean as juveniles and again on their journey back upstream as adults. For instance, as adults migrate through the lower Columbia River dams, they are faced with hot water temperatures between 72 - 73°F and must continue to migrate through 4 other hot and stagnant reservoirs in the lower Snake River, often disrupting migration and increasing susceptibility to disease, suffocation (warm water carries less oxygen) and in the worst case - death.

Salmon and steelhead require clean, cold water, intact/contiguous rivers, and reliable streamflows for spawning, rearing, and migrating. Before the dams were built, juvenile salmon were able to migrate quickly to the ocean - within a few days to several weeks - due to the swiftly moving current of the mainstem Snake and Columbia rivers. Now, because of the harmful conditions created by the lower Snake River dams and their hot reservoirs, salmon and steelhead require on average more than a month to reach the ocean. Up to 70 percent of all out-migrating smolts can be killed each year before they reach the ocean as a result of dam encounters, hot stagnant reservoirs, in-reservoir predation, and extended travel time.

The science is clear: restoring the Snake River by removing the four lower Snake River dams is an essential action we must take as quickly as possible, or we will lose these wild salmon and steelhead populations forever.

A note on the data: The 2023 lower Snake River and lower Columbia River water temperature data presented in the Hot Water Report are collected from the Columbia River DART program by Columbia Basin Research, University of Washington, using data courtesy of the U.S. Army Corps of Engineers (USACE) and USGS. Tables were assembled by SOS Staff.

III. A Look at Snake River Wild Salmon & Steelhead Adult Returns as of September 11, 2023

The Snake River's anadromous fish populations have been on a steady downward trajectory for decades. These salmon and steelhead face multiple obstacles, including increasingly hot water in the summer months in the lower Snake River reservoirs. Below are the current estimated returns for native Snake River fish so far, including (1) wild Snake River Spring/Summer Chinook, (2) wild steelhead, and (3) wild/natural sockeye. We will also look at how the historical and 2023 adult returns compare to established recovery goals – the adult fish returns deemed necessary to recover these populations to abundance and remove them from the Endangered Species Act list.

In summary - since the four lower Snake River dams were built, over 60 years ago, Snake River salmon and steelhead populations have steadily declined. Long before the dams were built, scientists predicted that the construction of the lower Snake River dams would devastate salmon and steelhead populations. Over the past several decades, these fish have returned annually far below the recovery goals necessary to remove them from the protections of the Endangered Species Act. Without immediate and meaningful conservation actions, scientists predict these populations will continue to decline to extinction.

1) Wild Snake River Spring/Summer Chinook:

• Endangered Species Act Status: Threatened (listed in 1992)
• Historical Annual Return: Over 2 million
• Columbia Basin Partnership Recovery Goal: Escapement of 127,000 wild adults per year
• Endangered Species Act Delisting Goal: 43,000 wild Snake River Spring/Summer Chinook
• 2023 Estimated Wild Returns: 10,714 wild Snake River Spring/Summer Chinook

2) Wild Steelhead: 

• Endangered Species Act Status: Threatened (listed in 1997)
• Historical Annual Return: Over 1 million
• Columbia Basin Partnership Recovery Goal: Escapement of 104,500 wild adults per year
• Endangered Species Act Delisting Goal: 30,800 wild steelhead
• 2022/2023 Wild Returns: 19,138 wild steelhead

3) Wild/natural sockeye: 

• Endangered Species Act Status: Endangered (listed in 1991)
• Historical Annual Return: Over 100,000+/yr to central Idaho’s high mountain lakes
• Columbia Basin Partnership Recovery Goal: 9,000 wild adults per year to the Stanley Basin
• Endangered Species Act Delisting Goal: 2,500 wild/natural-origin sockeye
• 2023 Estimated Wild Returns: 26 wild/natural-origin sockeye

A note on the ‘Snake River Wild Salmon Returns’ report: The data from this report comes from the Fish Passage Center and Idaho Department of Fish and Game. Tables and graphs were assembled by Idaho Rivers United staff.

IV. Urgency to restore the lower Snake River - to recover its native fish

This summer, due to hot water in the reservoirs of the lower Columbia and lower Snake rivers, roughly 80% of the returning adult Snake River sockeye that entered the mouth of the Columbia River died before spawning. In Hot Water Report Issue 9, Miles Johnson, Legal Director of Columbia Riverkeeper reported, “Hot water in these reservoirs prevented almost an entire generation of critically endangered fish from reaching their spawning gravels in Idaho—violating the Endangered Species Act and dealing another blow to the Shoshone-Bannock Tribes’ long-running effort to recover this unique and culturally important species...Without big improvements in water quality, federal scientists predict that adult Snake River sockeye survival will further decline by 80% in coming years, likely resulting in extinction.”

Since the completion of the dams on the lower Snake River, wild Snake River fish returns have plummeted and are far below the levels required to delist them from the Endangered Species Act, much less meet their Columbia Basin Partnership recovery goal (as seen in the above section 3). According to Nez Perce Tribe fishery scientists, nearly half of Snake River salmon and steelhead populations have reached quasi-extinction thresholds—a critical threshold signaling they are nearing extinction, and without intervention, they may not persist.

Sockeye salmon with lesions dying from hot water in the Columbia-Snake River Basin ©Conrad Gowell

A restored lower Snake River would provide the largest availability of high-quality free-flowing, cold-water habitat for salmon populations to recover to significant levels of abundance, and help to mitigate the impacts of cyclic ocean conditions and climate change. The benefits of dam removal would improve the ability of migrating fishes to access high-elevation, groundwater- and snowmelt-fed freshwater refuges, likely increasing survival and productivity in what will be an otherwise inhospitable future climate.

At this moment, we have an opportunity to restore ecosystem health in the heart of the Columbia Basin and recover salmon and steelhead abundance by removing the four lower Snake River dams and replacing their services. A restored, healthy, and resilient lower Snake River is necessary to protect the Northwest native fish from extinction and uphold our nation's promises to Tribes by reconnecting this emblematic fish to 5,500 miles of pristine, protected river and streams in Idaho, Oregon, and Washington. Restoring the lower Snake River through dam removal is our most significant river and salmon restoration opportunity anywhere in the nation today. 

Sockeye salmon with lesions dying from hot water in the Columbia-Snake River Basin ©Conrad Gowell

I. INTRODUCTION

Welcome to the 2023 Hot Water Report: Warming Waters in the Lower Snake and Columbia Rivers.

During the summer, this weekly report provides an update on real-time water temperatures in the lower Snake and Columbia River reservoirs via graphs and analyses, a summary of the highest weekly water temperatures at the forebay/reservoir of each federal dam, and a monthly status of adult returns for different salmon and steelhead populations as they make their way back to their natal spawning grounds. We’ll report first-hand from scientists, Tribal members, fishing guides, advocates, and other experts about the challenges facing these rivers – and our opportunities to improve and restore them - in order to recover healthy, resilient fish populations and the benefits they deliver to Northwest communities, other fish and wildlife populations (including the critically endangered Southern Resident orca), and ecosystems.

Many once-abundant anadromous fish populations—fish that hatch in freshwater, go to sea, and return to freshwater to spawn—in the Columbia-Snake River Basin are on the brink of extinction today due primarily to harms caused by federal dams and their warming reservoirs. The Columbia-Snake federal hydro-system harms and kills both juvenile and adult fish in multiple ways, including by elevating water temperatures in the summer months in their large, stagnant reservoirs. These cold-water fish begin to suffer harmful effects when water temperatures exceed 68° Fahrenheit.

This week, on the lower Snake River, the reservoir behind the Ice Harbor Dam registered the highest water temperature at 70.65°F on September 1. Issue 10 is focused on the Nez Perce Tribe’s Department of Fisheries Resources Management’s 2023 Snake River Basin Anadromous Fish Status Report Card that outlines (i) the historical returns for Snake River fish, (ii) forecasted 2023 returns for Spring/summer Chinook salmon and steelhead, (iii) Quasi-Extinction Threshold for Spring/summer Chinook salmon and steelhead (QET; critical threshold signaling fish are nearing extinction), and (iv) urgency to restore Snake River fish.

Without immediate and meaningful conservation actions, Snake River salmon and steelhead populations will continue to decline toward extinction. Restoring a free-flowing Snake River by removing its four dams and replacing their services is essential to provide cold, clean, healthy water for salmon and steelhead, recover and protect these once-highly prolific fish populations from extinction, uphold our nation's promises to Tribes, and help feed critically endangered Southern Resident orcas.

View the past Hot Water Report issues here: Hot Water Reports - Compiled

The Hot Water Report is a joint project of the Save Our wild Salmon Coalition, American Rivers, Association of Northwest Steelheaders, Columbia Riverkeeper, Earthjustice, Endangered Species Coalition, Environment Oregon, Idaho Conservation League, Idaho Rivers United, Natural Resources Defense Council, National Wildlife Federation, Northwest Sportfishing Industry Association, Orca Network, Sierra Club, Snake River Waterkeeper, Wild Orca and Wild Steelhead Coalition.

II. READING THE DATA - Water Temperatures in the Lower Snake and Columbia Rivers

Figure 1. Lower Snake River Water Temperatures - 2023 Daily Average and 10-year Average. Click on the image to view the graph.

Introduction to the data:
The daily average temperature at the four reservoir forebays (measured with sensors stationed at various depths below the reservoir surface, immediately upstream from the dam) in the lower Snake River (above) and the lower Columbia River (below) for 2023 is represented with solid lines and the 10-year average (2013 - 2023) temperatures with dashed lines of the same color. The dotted line across the graph represents the 68°F “harm threshold” for adult and juvenile fish.

The longer and the higher these temperatures rise above 68°F, the greater the harm, including: migration disruption, increased metabolism, increased susceptibility to disease, reduced reproductive potential (by reducing egg viability), suffocation (warm water carries less dissolved oxygen), and in the worst case - death.

The four reservoirs on the lower Snake River are large, stagnant pools that absorb enormous amounts of solar radiation that cause the water to warm. These waters inundate and destroy diverse micro-habitats that healthy rivers support, including cold-water refuges that salmon and steelhead rely upon during their migration. Without these vital pockets of cold water, salmonids cannot rest and recover on their journeys—adults moving upstream to spawn and juveniles moving downstream to the ocean. Rising temperatures and reductions in snowpack in recent decades due to climate change create warmer waters, which results in lower survival and reduced reproductive success for salmon and steelhead.

Figure 2. Lower Columbia River Water Temperatures - 2023 Daily Average and 10-year Average. Click on the image to view the graph.

Discussion of data:
Since April, temperatures in the lower Snake River and the lower Columbia River reservoirs have steadily increased. Figure 1 shows, the reservoir behind the Ice Harbor Dam had the highest average temperature of 70.41°F on September 1. The Lower Monumental reservoir had the second highest average temperature of 69.08°F on September 1.

Figure 2 shows the reservoir behind the Bonneville Dam registered the highest average temperature of 70.52°F on September 1. Both juvenile and adult salmon continue to experience water temperatures above the 68°F “harm” threshold.

Below, we present the weekly high water temperatures for each reservoir on the lower Snake and Columbia rivers for September 1 - September 6.

A note on the data: The 2023 lower Snake River and lower Columbia River water temperature data presented in the Hot Water Report are collected from the Columbia River DART program by Columbia Basin Research, University of Washington, using data courtesy of the U.S. Army Corps of Engineers (USACE) and USGS. The 10-year average water temperature data is courtesy of the Fish Passage Center. There is no data available for the Lower Monumental 10-year average water temperature, and McNary reservoir hourly water temperature data is collected from USACE with current available data. Little Goose Dam's daily average and hourly data are unavailable for September 6. Graphs and tables were assembled by SOS Staff.

III. WEEKLY HIGH WATER TEMPERATURES: September 1 - September 6

This week, on the lower Snake River, the reservoir behind the Ice Harbor Dam registered the highest water temperature at 70.65°F on September 1, and the Lower Monumental Dam registered the second highest temperature at 69.40°F on September 1.

This week, on the lower Columbia River, the Bonneville reservoir registered the highest water temperature at 70.52°F on September 1 and 2.

IV. Nez Perce Tribe’s 2023 Snake River Basin Anadromous Fish Status Report Card

Since time immemorial, the Nez Perce Tribe, also recognized as the Nimiipuu, have been connected to the lands and waters of modern-day Idaho, Washington, Oregon, and Montana - long before the creation of the Nez Perce Reservation in the mid-1800s.¹ As a sovereign nation within the United States, the Nez Perce Tribe retains the “inherent right to fish at usual and accustomed fishing stations, and hunt, gather, and graze livestock on open and unclaimed lands, all outside of the reservation boundary.”¹ However, due to forces such as settler encroachment and dam construction, the number of traditional fishing sites for the Nez Perce Tribe and the overall fish populations have declined precipitously.² The Nez Perce Tribe’s Department of Fisheries Resources Management is a critical program that works to protect and enhance fishing rights reserved by the Tribe in its treaties with the United States.³ Notably, the Department of Fisheries Resources Management have significantly rebuilt Snake River Fall Chinook returns, re-established Snake River coho salmon - extirpated in the 1980s from the Snake River Basin - and has become one of the largest and most successful tribal fisheries programs in the United States.³ 

In May 2021, the Department of Fisheries Resources Management released an analysis called “Snake Basin Chinook and Steelhead Quasi-Extinction Threshold Alarm and Call to Action.” That analysis indicated that nearly half of the wild spring Chinook populations in the Snake River Basin have crossed a critical threshold known as the Quasi-Extinction Threshold (QET), signaling they are nearing extinction, and without immediate intervention, many may not persist in the coming years. In addition, the basin’s steelhead populations also face alarming threats to their continued existence.

To understand what Quasi-Extinction Threshold (QET) means, the department outlined a key definition:

• QET means 50 or fewer natural-origin spawners on the spawning grounds for 4 consecutive years.
• QET also signifies that adult salmon abundance in a population nearing absolute extinction, and the probability of recovery is low without substantial intervention.

“Quasi-Extinction means, aside from biological terminology, you are running out of options. When you have fewer than 50 fish on spawning grounds, the genetic diversity is really limited. Your ability to pull these fish out of inbreeding depression and other stochastic-type risks is really limited. Any type of environmental hazard can cause havoc when you have fish populations that are so low. We are certainly running out of management options.” —Dave Johnson, Department Manager of the Nez Perce Tribe’s Department of Fisheries Resources Management

The Snake and Columbia River Basin contains some of the very best available habitat for salmon populations to recover to any significant level of abundance. However, with predictions pushing the populations below 50 spawners, the four lower Snake River dams are a major factor preventing salmon from reaching spawning grounds and reproducing in viable numbers.

Without immediate and meaningful conservation actions, Snake River salmon and steelhead populations will continue to decline toward extinction. Projected returns of adult spring/summer Chinook salmon in 2023 are estimated to be about half the 2022 return. Returns of adult steelhead in 2023 are similar to the 2022 return. Both are far below the goals for healthy, harvestable and abundant salmon and steelhead.

Below is the Nez Perce Tribe’s Department of Fisheries Resources Management’s 2023 Snake River Basin Anadromous Fish Status Report Card that includes historical returns for Snake River fish, forecasted 2023 returns for Spring/summer Chinook salmon and steelhead, QET, and urgency to restore Snake River fish.

2023 Snake River Basin Anadromous Fish Status Report Card

Figure 1. Snake Basin salmon and steelhead stock specific population status summary; over half the historical populations are extinct and none of the existing populations are considered healthy and harvestable.

Historical Context:
The abundance, diversity, and distribution of Snake Basin salmon and other anadromous fish (steelhead, lamprey, sturgeon) are just a sliver of their historical condition:

• Less than half of the 117 historical populations remain(Figure 1).
• Abundance of wild fish in the remaining populations is 1-2% of the 2+ million historical abundance (Figure 2).
• The Columbia Basin Partnership (CBP) Phase 2 Report A Vision for Salmon and Steelhead: Goals to Restore Thriving Salmon and Steelhead to the Columbia River Basin | NOAA Fisheries establishes contemporary management goals.

Figure 2. Snake Basin salmon and steelhead current abundance (black dots) relative to historical abundance and Columbia Basin Partnership (CBP) goals; Columbia Basin Partnership high-range goals 5 – 31% of historical. All but one stock below low-range goals. Fall Chinook salmon above low-range, but below mid-range goals.

Recent Status: Spring/summer Chinook salmon and steelhead are on the brink of extinction.

1) Wild Spring/summer Chinook salmon

Figure 3.1. Assessment of Snake Basin wild spring/summer Chinook salmon abundance relative to Quasi-Extinction Threshold (QET) of 50 or fewer spawners. Actual abundance updated through 2022 returns and future abundance modeled through 2027. Red font and data points indicate populations and years with abundance below QET threshold. 

• Wild spring/summer Chinook salmon returns from 2018 through 2021 to the Snake Basin averaged 6,050 fish with 42% of the Endangered Species Act (ESA)-listed populations being at or below the Quasi-Extinction Threshold of 50 fish for four consecutive years (Figure 3.1).  

Figure 4. Annual (abundance of adult wild spring/summer Chinook salmon passing into the Snake Basin relative to critical (quasi-extinction index), ESA-delisting index, Columbia Basin Collaborative healthy and harvestable (high range) thresholds. Data provided by Idaho Department of Fish Game (Baum et al 2022 and T. Copeland personal communication).

• Wild spring/summer Chinook salmon returns in 2022 were slightly higher at 16,048 fish but are still well below the Index for ESA-delisting (43,000) and far from the healthy and harvestable goal (235,000).
• Forecasted natural-origin spring/summer Chinook salmon return for 2023 is ~7,500 adults (Figure 4).
• The QET assessment was updated to reflect the 2022 returns. Generally, adult returns in 2022 were slightly higher and reduced the number of populations at or below the QET criteria of 50 natural-origin spawners.

“The increase in Snake River basin natural-origin spring/summer returns in 2022 is welcomed and consistent with our expectations for improved survival under good ocean conditions and high spill hydro-operations. However, it is important to understand that while the 2022 return is an improvement over recent years, abundance remains precariously low and well below criteria for ESA-delisting - let alone our goals representing healthy and harvestable status.”—Jay Hesse, Director of Biological Services of the Nez Perce Tribe’s Department of Fisheries Resources Management

2) Wild Steelhead

Figure 3.2. Assessment of Snake Basin wild steelhead abundance relative to Quasi-Extinction Threshold (QET) of 50 or fewer spawners. Actual abundance updated through 2022 returns and future abundance modeled through 2027. Red font and data points indicate populations and years with abundance below QET threshold.

• Wild steelhead returns from 2018 through 2021 to the Snake River Basin averaged 12,297 fish with 19% of the ESA listed populations being at or below the Quasi-Extinction Threshold of 50 fish for four consecutive years (Figure 3.2).
• Wild steelhead returns in 2022 were 9,807 fish well below the Index for ESA-delisting (30,800) and healthy and harvestable goal (147,300).
• Forecasted natural-origin steelhead return for 2023 is ~9,500; with less than 1,000 B-run natural-origin predicted.

Future Trend:
If adult abundance continues to decline at a similar rate as the last 10-years, over 60% of the spring/summer Chinook salmon populations and 44% of the steelhead populations may drop below 50 natural origin spawners by 2027 and some populations (e.g. Tucannon spring Chinook salmon) will likely become extinct (Figure 3.1 and 3.2).

Urgency:
To achieve the Columbia Basin Partnership’s Snake Basin spring/summer Chinook salmon mid-range goal (137,000 natural origin fish at Lower Granite Dam) by 2050, abundance from each generation to the next must increase by at least 44% for the next 27 years (seven generations) (Figure 5).

Figure 5. Observed generational growth rate of Snake Basin spring/summer Chinook salmon versus targeted minimum generational growth rate necessary to achieve mid-ranged goals (137,000) by 2050. Red bars indicate generations that had fewer progeny returning than their parents (generational decline). Yellow bars (none in this time series) indicate generations with more progeny returning than their parents (generational increase, but at level insufficient to reach 137,000 by 2050). Blue bars indicate generations with more progeny than their parents (generational increase, at level sufficient to meet or exceed 137,000 by 2050. Black bar reflects current in-season projection for 2023.

Transformative Actions:

An analysis of the actions necessary to achieve healthy and abundant salmon and steelhead, recently completed by the National Oceanic and Atmospheric Administration (NOAA) Fisheries Rebuilding Interior Columbia Basin Salmon and Steelhead and the Statement of the American Fisheries Society (AFS) and the Western Division AFS (WDAFS) About the Need to Breach the Four Dams on the Lower Snake River, reports that breaching the four lower Snake River dams is necessary and essential, along with a comprehensive suite of other actions.

"Breaching the dams improves survival [by speeding] the passage down to the ocean so fish travel in a river, not in a series of reservoirs. The fish evolutionarily are developed to make it down to the ocean in a certain amount of time. Well, we've extended that period of time to a month so they run out of reserves, they run out of their food by the time they reach the ocean. The only way these fish are going to have a chance is if they can get back to the mountains. Otherwise, we lose them. We're losing them every year, and we need to turn that around. We need to be able to breach the dams to have those fish get to where they're supposed to be.” —Dave Johnson, Department Manager of the Nez Perce Tribe’s Department of Fisheries Resources Management

Data used by the Nez Perce Tribe’s Department of Fisheries Resources Management:
Adult salmon and steelhead returns are monitored at lower Snake River dams and in tributary (population) habitats.

• Real-time (in-season) and annual fish ladder window counts of combined wild and hatchery-origin fish can be found at Fish Passage Center’s website (https://www.fpc.org/currentdaily/HistFishTwo_7day-ytd_Adults.htm) https://www.fpc.org/currentdaily/HistFishTwo_7day-ytd_Adults.htm and the Columbia Basin Research website (https://www.cbr.washington.edu/dart/query/adult_daily).
• Separate estimates of wild-origin abundance and hatchery-origin abundance are generated post-season for fish passing Lower Granite Dam and available on the StreamNet website:
  • Natural Chinook - https://www.streamnet.org/data/trends/trend/?trendid=46108;
  • Hatchery Chinook - https://www.streamnet.org/data/trends/trend/?trendid=46109;
  • Natural Steelhead - https://www.streamnet.org/data/trends/trend/?trendid=46110;
  • Hatchery Steelhead - https://www.streamnet.org/data/trends/trend/?trendid=46111.
  • Spring/summer Chinook and steelhead estimates are described in Idaho Department of Fish and Game Technical reports (Baum et al 2022; https://collaboration.idfg.idaho.gov/FisheriesTechnicalReports/Res22-11Baum2020Wild%20Adult%20Steelhead%20Chinook%20Salmon%20Abundance.pdf and fall Chinook salmon are provided on the Nez Perce Tribe website (http://kus.nptfisheries.org/kus-data).
• Population specific estimates of wild-origin, hatchery-origin, and total spawner abundance are available on the StreamNet website (https://www.streamnet.org/home/data-maps/fish-hlis/).

References:
1. Nez Perce Tribe History: Traditional Ways and Treaties
2. Honoring Nations, Nez Perce Tribe Fisheries
3. Nez Perce Tribe: Fisheries Resources Management: DFRM-Management-Plan-2013-2028.pdf(nezperce.org)

Sockeye salmon with lesions dying from hot water in the Columbia-Snake River Basin ©Conrad GowellWelcome to the Hot Water Report: Warming Waters in the Lower Snake and Columbia Rivers. 

I. EXECUTIVE SUMMARY

• For decades, summer water temperatures in the lower Snake and Columbia rivers have been rising to levels that are lethal to salmon and steelhead, due to the presence of dams and their hot, stagnant reservoirs. 
• All four Snake River salmon and steelhead populations are listed as threatened or endangered. Populations declined precipitously shortly after the dams were constructed. 
• On August 2023, Ice Harbor Dam’s reservoir reached 72.73°F —more than 4 degrees above the 68°F “harm” threshold, the legal and biological limit identified to protect salmon.
• Extreme heat warnings are becoming more frequent across the country this year. In particular, the Northwest is expected to experience above-average high temperatures, continued drought emergencies, and low river flow conditions—all of which threaten to increase river temperatures to harmful levels.  
• Scientists have reached a conclusive answer: Restoring the lower Snake River by breaching the four dams is the only action available to provide cooler water temperatures and protect salmon and steelhead from extinction.

II. INTRODUCTION

Salmon Columbia River © Dave McCoy

For millennia, wild Snake and Columbia River salmon and steelhead have delivered vast cultural, economic, nutritional, and ecological benefits to the people, fish, and wildlife of the Northwest. Before the lower Snake River dams were built, the pristine, clear, cold waters of the Snake River Basin were home to millions of adult salmon and steelhead. Each year, they return from the Pacific Ocean, swimming against the current in search of their natal spawning gravels and delivering many millions of pounds of high-quality marine-derived nutrients to the landscape and wildlife of the Northwest. And even as they dwindle toward extinction, their resilient nature continues in a fight for the species’ survival.

Today, however, the dams and reservoirs have stilled the current, and salmon now require a month or more to reach the ocean, migrating in warm water reaching over 68°F the biological and legal threshold scientists identified to protect salmon. All four Snake River salmon and steelhead populations are listed as threatened or endangered under the Endangered Species Act and are at grave risk of extinction.

Restoring a free-flowing Snake River by removing its four lower dams and replacing their services is essential to provide cold, clean, healthy water for salmon and steelhead; protect and recover these once-highly prolific fish populations; uphold our nation's promises to Tribes; and help feed the critically endangered Southern Resident orcas and other fish and wildlife species.

During the summer, the Hot Water Report will provide an update on real-time water temperatures in the lower Snake and Columbia river reservoirs and reports from scientists, Tribal members, fishing guides, and other experts about the challenges facing these rivers, our opportunities to recover healthy, resilient fish populations, and the benefits they deliver to Northwest communities and other fish and wildlife populations.

View previous Hot Water Report issues at wildsalmon.org/HWR

III. Restoring a healthy lower Snake River for salmon and steelhead

Red lesions and white fungus on the salmons’ bodies are the result of high water temperatures and stress. © Conrad Gowell/Columbia Riverkeeper

In 2023, salmon and steelhead experienced another summer of hot, harmful water temperatures in the lower Snake River. From early July to September, all four lower Snake River reservoirs had water temperatures above 68°F, many of the reservoirs reaching over 62 days above 68°F. On August 2023, the reservoir behind the Ice Harbor Dam registered the highest temperature recorded during the summer at 72.73°F – more than 4 degrees above the 68°F “harm” threshold.

This year, warnings of extreme heat are becoming more frequent across the country and in the Northwest. The NW is expected to see above-average high temperatures, continued drought emergencies, and low river flow conditions, all of which signal that river water temperatures will increase to harmful levels.

Wild salmon returning to the Snake River Basin are 0.1-2% of the abundance at the time the United States entered the 1855 Treaties with Tribes.¹ Many of the Columbia-Snake River Basin salmon runs have been locally extirpated. Thirteen populations, including all four Snake River populations, are listed as threatened or endangered under the Endangered Species Act and remain at risk of extinction. In recent decades, adult salmon and steelhead migrating upriver to spawning grounds in the Columbia Basin have suffered decreased survival, largely in part due to the dangerously warm water in the Snake and Columbia Rivers, caused by dams that created slack water reservoirs.

Salmon Ecology:

Scaffold fishing at Celilo, Joe Palmer fishing from a hanging scaffold on Standing Island. Aug 1952. © Columbia River Inter-Tribal Fish Commission/Raymond Mathen

“The percentage of natural-origin salmon and steelhead returning to spawn today compared to historic levels is even smaller; wild-origin returns of salmon to the Snake Basin are 0.1-2% of their historical abundance, with many populations at or below a quasi-extinction threshold. Because of the severe lack of fish, the Basin Tribes cannot exercise their harvest rights to the same extent they could at the time the rights were reserved in treaties or in executive orders.” – Tribal Circumstances Analysis, prepared by Department of Interior in collaboration and coordination with the Columbia Basin Tribes

Since time immemorial, salmon have been integral and profoundly fundamental to Northwest Tribes’ spiritual and cultural identity, economic prosperity, and sovereignty.² Salmon and steelhead are a critical nutrient link between oceans, rivers, streams, forests, and wildlife. Salmon runs function as enormous pumps that provide vast amounts of marine nutrients from the ocean to river systems.³ Over 137 species benefit from and utilize the ocean-origin nutrients that salmon and steelhead deliver.⁴ Because of their vast ecological impact, salmon are considered a keystone, connector, and indicator species. In other words, salmon have unique and substantial effects on their own and neighboring environments such that no other species can replace its particular ecological role. When keystone species are removed, the entire ecosystem typically collapses.

The state of salmon populations reflects the overall health of the ecosystem as a whole. When salmon populations are in peril, it indicates that the entire ecosystem is unhealthy and/or under stress.

The lower Snake River dams' impact on freshwater habitat and salmon:

Salmon and steelhead require clean, cold water, intact and contiguous rivers, and reliable streamflows for spawning, rearing, and migration. Prior to the construction of the four dams on the lower Snake River, the pristine, clear, cold waters of the Snake River Basin were home to millions of adult salmon and steelhead.⁵ When the Columbia-Snake rivers flowed freely, juvenile salmon and steelhead took as few as five days to complete their migration to the ocean– due to the swiftly moving current of the Snake and Columbia rivers. Today, however, the dams and reservoirs have stilled the current, and salmon now require a month or more to reach the ocean.

Now, endangered Snake River salmon and steelhead must traverse through four dams on the lower Columbia River and four dams on the lower Snake River on their migration to the ocean and again on their journey back upstream as adults.

“Scientific studies continue to show that breaching the four lower Snake River dams would provide greater certainty of achieving long-term survival and recovery of native wild fishes more than any other measure or combination of measures without dam breaching.” – The American Fisheries Society (AFS) and The Western Division AFS

The lower Snake River dams create stagnant reservoirs, which are large, slow-moving pools which absorb enormous amounts of solar radiation, causing water temperature to reach lethally high levels. The reservoirs warm during the summer months and create a block of slow-moving hot water that retains the heat through the night and does not cool only until air temperatures drop. These warming waters inundate and destroy diverse micro-habitats that healthy rivers support, including cold-water refuges that salmon and steelhead rely upon during summer migrations. Without these vital pockets of cold water, salmonids cannot rest and recover on their journeys – adults moving upstream to spawn and juveniles moving downstream to the ocean.

Warming waters in the lower Snake and Columbia Rivers:

Sockeye salmon dies after record high temperatures in the Columbia River. © Conrad Gowell/Columbia Riverkeeper

The reservoirs on the lower Snake River increasingly warm the river above critical levels from July to mid-September, significantly reducing salmon reproduction and survival. Excessively high water temperatures, above 20°C/68°F (this threshold is the legal and biological limit scientists identified to protect salmon), are now normal for extended periods in July, August, and September.⁶

Rising temperatures and reductions in snowpack in recent decades due to climate change have resulted in warmer waters, which results in lower survival and reduced reproductive success for salmon and steelhead. The lower Snake River dams exacerbate these already warmed waters, creating conditions that harm these fish. Studies have also indicated that all Snake River salmon species (sockeye, spring/summer Chinook, fall Chinook, and steelhead) experience reduced survival at elevated water temperatures above 64°F, depending on the timing of their upriver migration.⁷ Steelhead, fall Chinook, and sockeye have greater exposure to high temperatures because they migrate in the summer when temperatures are hottest. When water temperatures rise above 68°F, the longer the time they remain above that threshold, the greater the harm, including migration disruption, increased metabolism, increased susceptibility to disease, reduced reproductive potential (by reducing egg viability), suffocation (warm water carries less dissolved oxygen), and in the worst case - death.

“Cold-water resources to protect migrating salmonids in the existing hydrosystem are extremely limited; there are no additional resources available that can significantly cool the river. Restoring the lower Snake River by removing its four federal dams will significantly reduce mainstem water temperatures on a long-term basis, and is likely the only action that can do so, substantially lowering the risk of extinction for salmon and steelhead.” –  Letter to NW policymakers signed by 55 Fisheries and natural resource scientists 

Due to the elevated water temperatures in the stagnant reservoirs and other harm caused by the lower Snake River dams, salmon runs have been in steep decline for several decades. The decline of once-abundant salmon, steelhead, and other species in the Columbia River Basin has severely and inequitably impacted Tribes’ spiritual, cultural, physical, and economic health.⁸ Without immediate and meaningful conservation actions to reconnect the Northwest’s most emblematic fish to over 5,500 miles of pristine, cold-water river and streams in Idaho, Oregon, and Washington, Snake River salmon and steelhead populations will continue to decline toward extinction. Restoring a free-flowing Snake River by removing its four dams and replacing their services is essential to provide cold, clean, healthy water for salmon and steelhead, recover and protect these once-highly prolific fish populations from extinction, uphold our nation's promises to Tribes, and help feed critically endangered Southern Resident orcas.

References:
1. 8. Tribal Circumstances Analysis developed by the Department of Interior, in collaboration and coordination with the Columbia Basin Tribes.
2. Columbia River Inter-Tribal Fish Commission: Columbia River Fish Species.
3. Wild Salmon Center: Why protect Salmon.
4. The National Wildlife Federation: Chinook Salmon.
5. Columbia River Inter-Tribal Fish Commission: Tribal Salmon Culture.
6. 7. Letter to NW policymakers signed by 55 Fisheries and natural resource scientists.

IV. READING THE DATA - LOWER SNAKE AND COLUMBIA RIVER TEMPERATURES

Introduction to the water temperature data:

• Throughout this summer, the Hot Water Report will provide, on a weekly basis, an update on real-time water temperatures in the lower Snake and Columbia River reservoirs.
• The daily average and high water temperature data at the four reservoir forebays are measured with sensors stationed at various depths below the reservoir surface, immediately upstream from the dams in the lower Snake River and the lower Columbia River for 2024.
• Daily average temperatures are represented with solid lines and the 10-year average (2014 - 2023) temperatures with dashed lines of the same color.
• The dotted line across the graph represents the 68°F “harm threshold” for adult and juvenile fish.

V. DISCUSSION OF DATA - LOWER SNAKE AND COLUMBIA RIVER TEMPERATURES

AVERAGE LOWER SNAKE AND COLUMBIA RIVER TEMPERATURES 6/19 - 6/25:

Figure 1. Lower Snake River Water Temperatures - 2024 Daily Average and 10-year Average. Click on the image to view the graph.

Figure 2. Lower Columbia River Water Temperatures - 2024 Daily Average and 10-year Average. Click on the image to view the graph.

Discussion of average water temperature data:

• Since April, temperatures in the lower Snake River and the lower Columbia River reservoirs have steadily increased.
• Figure 1. Lower Snake River Water Temperatures: this week, the reservoir behind the Ice Harbor Dam reached a high average water temperature of 64.26°F on June 24 - June 25.
• Figure 2. Lower Columbia River Water Temperatures: this week, the reservoir behind the Bonneville dam had a high average temperature of 63.32°F on June 24 - June 25.
• Most water temperatures in the lower Snake River and lower Columbia River have reached at or above their 10-year averages. As we near the end of June, the water temperatures are below the 68°F “harm” threshold, which is good news for cold-water species like salmon and steelhead. However, we expect these temperatures will rise considerably in these reservoirs as the summer progresses.

WEEKLY HIGH TEMPERATURES IN THE LOWER SNAKE AND COLUMBIA RIVER: 6/19 - 6/25

• On the lower Snake River, the reservoir behind the Ice Harbor Dam registered the highest water temperature of 64.72°F.

• On the lower Columbia River, the McNary reservoir registered the highest water temperature at 64.53°F.

Data Sources: The 2024 lower Snake River and lower Columbia River water temperature data presented in the Hot Water Report are collected from the USGS, Columbia River DART program by Columbia Basin Research, University of Washington, using data courtesy of the U.S. Army Corps of Engineers (USACE). The 10-year average water temperature data is courtesy of the Fish Passage Center. There is no data available for the Lower Monumental 10-year average water temperature. Graphs and tables are assembled by SOS Staff.

 The Hot Water Report is a joint project of the Save Our wild Salmon Coalition, Association of Northwest Steelheaders, Columbia Riverkeeper, Earthjustice, Endangered Species Coalition, Idaho Conservation League, Idaho Rivers United, National Wildlife Federation, Northwest Sportfishing Industry Association, Orca Network, Sierra Club, Snake River Waterkeeper, and Wild Steelhead Coalition.

View previous Hot Water Report issues at wildsalmon.org/HWR

Sockeye salmon with lesions dying from hot water in the Columbia-Snake River Basin © Conrad Gowell
Welcome to the Hot Water Report 2024: Warming Waters in the Lower Snake and Columbia Rivers.

 I. EXECUTIVE SUMMARY

• Returning adult Snake River salmon and steelhead are struggling today to migrate through harmful/potentially lethal water temperatures in the lower Snake and Columbia rivers. As of August 29, many of the reservoirs have approached over 50 days above 68°F “harm” threshold.
• The four federal dams and their hot water reservoirs on the lower Snake River continue to be a major driver of salmon and steelhead mortality and heat pollution on the lower Snake River.
• For decades, federal agencies have long resisted any meaningful action to reduce the dams’ water temperature pollution. Columbia Riverkeeper and many others have used science and the Clean Water Act to increase pressure on the U.S. Army Corps of Engineers (Corps) to reduce heat pollution caused by the lower Snake River dams.
• Despite the Corps’ attempts to ignore potential solutions that keep the lower Snake River dams and reservoirs from warming to levels that kill endangered salmon, the Washington Department of Ecology recently used its Clean Water Act authority to require the Corps to study all possible ways to cool the lower Snake River.

II. INTRODUCTION

'Columbia Meets The Pacific' 40x60 © Rachel Teannalach

Before the lower Snake River dams were built, the pristine, clear, cold waters of the Snake River Basin were home to millions of adult salmon and steelhead, along with sturgeon, lamprey eel, and other native fishes. The once-abundant anadromous fish populations in the Columbia-Snake River Basin (fish that hatch in freshwater, go to sea, and return to freshwater to spawn) are struggling to survive today primarily due to harms caused by the federal dams and their warming reservoirs. The federal hydro-system creates conditions that harm and kill both juvenile and adult fish, including by elevating water temperatures in large, stagnant reservoirs in the summer months. These cold-water fish begin to suffer harmful effects when water temperatures exceed 68° Fahrenheit.

In Issue 10, Miles Johnson, Legal Director for Columbia Riverkeeper uncovers the critical role of the Clean Water Act in addressing dams’ hot water pollution, also known as heat pollution, to protect endangered salmon and steelhead from extinction and enable their recovery. This issue provides an in-depth review of how federal agencies such as the U. S. Army Corps of Engineers and the Bonneville Power Administration have purposely delayed the implementation of the Clean Water Act’s requirements to address heat pollution for decades. Now, directed by the Department of Ecology, the U.S. Army Corps of Engineers must put forward a new plan that examines all possible ways to cool the lower Snake River and reduce heat pollution.

During the summer, our Hot Water Report provides real-time water temperatures in the lower Snake and Columbia river reservoirs, with updates and reports from scientists, Tribal members, fishing guides, and other experts about the challenges facing these rivers, our opportunities to recover healthy, resilient fish populations, and the benefits they deliver to Northwest communities and other fish and wildlife populations.

View the Hot Water Report issues at wildsalmon.org/HWR

 III. READING THE DATA - LOWER SNAKE AND COLUMBIA RIVER TEMPERATURES

INTRODUCTION TO THE WATER TEMPERATURE DATA:

• Throughout this summer, the Hot Water Report will provide, on a weekly basis, an update on real-time water temperatures in the lower Snake and Columbia River reservoirs.
• Hot water temperature effects to salmon: The longer and the higher water temperatures rise above 68°F "harm" threshold, the greater the harm to salmon, including: migration disruption, increased metabolism, increased susceptibility to disease, reduced reproductive potential (by reducing egg viability), suffocation (warm water carries less oxygen), and in worst case - death.
• Data collection: The daily average and high water temperature data at the four reservoir forebays are measured with sensors stationed at various depths below the reservoir surface, immediately upstream from the dams in the lower Snake River and the lower Columbia River for 2024. The water temperatures are taken on the hour. Hourly temperatures are used to find the highest temperatures reached in each reservoir, and hourly temperature measurements are used to find the daily average temperatures.
• Average Water Temperature Graphs (below): Daily average temperatures are represented with solid lines, and the 10-year average (2014 - 2023) temperatures are with dashed lines of the same color. The dotted line across the graph represents the 68°F “harm threshold” for adult and juvenile fish.
• Weekly High Water Temperature Tables (below): This table outlines the highest water temperatures reported for each reservoir during the week and how many days water temperatures have exceeded 68°F.

IV. DISCUSSION OF DATA - LOWER SNAKE AND COLUMBIA RIVER TEMPERATURES

LOWER SNAKE RIVER WATER TEMPERATURES: 8/24 - 8/29

Lower Snake River - 2024 Daily Average and 10-year Average.

Lower Snake River Water Temperatures - 2024 Daily Average and 10-year Average. Click on the image to view the graph and click here to view the PDF version with separate graphs for each reservoir.

• Lower Snake River Water Temperatures: this week, the Ice Harbor Dam's reservoir experienced a high average water temperature of 70.64°F on August 24.
• The Lower Monumental Dam's reservoir registered a high average temperature of 69.42°F on August 24.
• The Little Goose Dam’s reservoir registered 68.52°F on August 26.
• The Lower Granite reservoir registered a high average of 67.31°F. Lower Granite Dam’s reservoir’s average and high daily temperatures registered below 67°F due to the US Army Corps of Engineers’ continued cold water release effort from the reservoir behind Dworshak Dam. Unfortunately, these cold water releases do not significantly cool/benefit the three downstream reservoirs on the lower Snake River.

WEEKLY HIGH TEMPERATURES IN THE LOWER SNAKE RIVER: 8/24 - 8/29

• Many of the lower Columbia and Snake river reservoirs continue to reach above the 68°F “harm” threshold, for over 50 days.
• The Ice Harbor Dam's reservoir registered the highest temperature of 70.77°F on August 24.
• Lower Monumental Dam’s reservoir registered a high water temperature of 69.58°F on August 24.
• The Little Goose Dam's reservoir reached the highest water temperature of 68.85°F on August 26. The Lower Granite Dam's reservoir registered a high water temperature of 68.18°F.
• Water temperatures in the Ice Harbor Dam reservoir have exceeded 68°F for 51 consecutive days. Lower Monumental Dam’s reservoir have exceeded 68°F for 53 days and Little Goose Dams’ reservoirs have exceeded 68°F for 52 days.

LOWER COLUMBIA RIVER WATER TEMPERATURES: 8/24 - 8/29

Lower Columbia River - 2024 Daily Average and 10-year Average.

Lower Columbia River Water Temperatures - 2024 Daily Average and 10-year Average. Click on the image to view the graph and click here to view the PDF version with separate graphs for each reservoir

• Lower Columbia River Water Temperatures: this week, all four reservoirs on the lower Columbia River exceeded 68°F.
• The reservoir behind John Day Dam had a high average temperature of 69.98°F on August 29. The reservoir behind The Dalles Dam reached an average temperature of 69.80°F on August 27.

WEEKLY HIGH TEMPERATURES IN THE LOWER COLUMBIA RIVER: 8/24 - 8/29

• This week, on the lower Columbia River, John Day Dam's reservoir reached the highest temperature at 70.52°F.
• Bonneville Dam reservoir has spent 55 consecutive days above 68°F and both The Dalles Dam and John Day Dam reservoirs registered above 68°F for 54 days.

Data Sources: The 2024 lower Snake River and lower Columbia River water temperature data presented in the Hot Water Report are collected from the USGS, Columbia River DART program by Columbia Basin Research, University of Washington, using data courtesy of the U.S. Army Corps of Engineers (USACE). The 10-year average water temperature data is courtesy of the Fish Passage Center. Lower Monumental 10-year average water temperatures are unavailable. Graphs and tables are assembled by SOS Staff.

V. Progress for Cold Water
How the Clean Water Act is forcing the Army Corps to get serious about reducing heat pollution from the Lower Snake River reservoirs

By Miles Johnson, Legal Director for Columbia Riverkeeper

'Snake River at Lewiston' 36x48 © Rachel Teannalach  

Good news for fish and fans of cold water: the Washington Department of Ecology recently used its Clean Water Act authority to require the Army Corps to study all possible ways to cool the lower Snake River!

The Clean Water Act is America’s flagship law protecting healthy streams, rivers, and lakes. Enacted when some of our nations’ waterways were so contaminated that they actually caught fire, the Clean Water Act’s common-sense goal is to ensure that rivers and lakes remain clean enough to support fishing, swimming, and (after appropriate treatment) drinking. Although significant threats to water quality obviously remain, the Clean Water Act has proven to be one of our nation’s most effective—and most popular—environmental laws.

All of this prompts the question: Does the Clean Water Act contain the tools and authorities to address hot water caused by dams on the lower Snake and Columbia rivers? In theory, the answer is yes, but federal agencies have long resisted any meaningful action to reduce the dams’ temperature pollution. So for the last decade, Columbia Riverkeeper and many others have used science and the Clean Water Act to increase pressure on the U.S. Army Corps of Engineers (Corps) to reduce the lower Snake River dams’ hot water pollution, also known as heat pollution.

Ecology’s recent decision is another important step toward that goal! Here’s a quick history of this issue:

• 2014: Columbia Riverkeeper sues the Corps for discharging oil and heat pollution into the lower Snake River without Clean Water Act Permits.

• 2015: 96% of adult endangered Snake River sockeye salmon die because of hot water in the lower Snake and Columbia rivers. Major temperature-related fish kills occur in the summers of 2013, 2021, and 2023.

• 2016: Columbia Riverkeeper and allies sue under the Clean Water Act to require EPA to create a pollution budget (called a Total Maximum Daily Load analysis, or TMDL) for heat pollution in the Columbia and lower Snake rivers.

• 2017: Columbia Riverkeeper uses computer modeling to show that, without the dams, the lower Snake River would be cool enough for salmon to migrate safely.

• 2019: Ninth Circuit Court of Appeals orders EPA to write a temperature specific Total Maximum Daily Load (TMDL) for the Lower Snake and Columbia Rivers.

• 2021: EPA releases a final temperature TMDL for the lower Snake and Columbia rivers. It identifies the dams and reservoirs as major sources of heat pollution, and sets numeric temperature reduction targets for each dam.

• 2022: As a result of Columbia Riverkeeper’s 2014 suit against the Corps, EPA finally issues Clean Water Act discharge permits for the Corps’ Lower Snake River dams. These permits require the Corps to make a plan (called a Water Quality Attainment Plan) to achieve the temperature reductions mandated by the TMDL.

• April 2024: The Army Corps submits a Water Quality Attainment Plan for the lower Snake River reservoirs that does not propose any meaningful changes to meet the temperature limits.

• March 2024: Columbia Riverkeeper and others submit comments to Ecology opposing the Corps’ inadequate temperature plan.

• June 2024: Ecology formally rejects the Corps’ proposed plan and directs the Corps to put forward a new plan that examines all possible ways to cool the lower Snake River.

What’s next? The Corps must study ways to keep the dams and reservoirs from warming the lower Snake River to levels that kill endangered salmon. Despite the Corps’ attempts to ignore potential solutions—like drawing down reservoirs for part or all of the year—Ecology made clear that nothing is off the table when it comes to studying what could be done to keep the lower Snake River cool.

The Corps has until September 1, 2024, to submit a detailed new plan or explain to Ecology the Corps’ procedure for producing a new plan in cooperation with Ecology, EPA, Tribes, and others.

We are making steady progress, and we remain hopeful, but we still have a long road ahead. Studying and implementing ways to keep the river cool will take several years, and we fully expect the Corps to continue resisting meaningful actions that benefit salmon and steelhead. Nevertheless, we remain dedicated to delivering on the Clean Water Act’s promise of clean, healthy waterways with abundant fisheries resources.

Stay tuned for updated information and opportunities to advocate for a healthy river!

The Hot Water Report is a project of the Save Our wild Salmon Coalition, Association of Northwest Steelheaders, Columbia Riverkeeper, Earthjustice, Endangered Species Coalition, Idaho Conservation League, Idaho Rivers United, National Wildlife Federation, Natural Resources Defense Council, Northwest Sportfishing Industry Association, Orca Network, Sierra Club, Snake River Waterkeeper, and Wild Steelhead Coalition.

View previous Hot Water Report issues at wildsalmon.org/HWR

Sockeye salmon with lesions dying from hot water in the Columbia-Snake River Basin © Conrad Gowell
Welcome to the Hot Water Report 2024: Warming Waters in the Lower Snake and Columbia Rivers.

I. EXECUTIVE SUMMARY

• Historically, the three Southern Resident orca pods – J, K, and L pods – have fed on an abundance of large, fatty Chinook salmon.
• Southern Resident orcas are listed as endangered in both the U.S. (listed in 2005) and Canada (listed in 2003). The lack of Chinook salmon is the single greatest threat to the survival of the Southern Resident orcas. Only 74 individual orcas survive today (according to the Center for Whale Research’s annual census of the Southern Resident population completed in January 2024).
• Snake River Spring/Summer Chinook and Snake River Fall Chinook as well as many Columbia-Basin salmon runs are ranked in the top 10 Priority Chinook stocks for orca recovery.
• Research conducted by Orca Behavior Institute, shows how abundant food sources are key to healthy orca populations. Similar to Bigg’s orcas recovery, with enough food, Southern Residents would be able to overcome threats, live healthier lives with their pods, and grow in population size.
• Scientists agree that recovering Chinook salmon is essential for the recovery of Southern Residents. Key actions to help achieve abundant salmon include removing the four lower Snake River dams to restore Snake River salmon runs, restoring salmon habitats across the Columbia-Snake River Basin, and protecting marine habitats in order to increase Southern Residents’ ability to reproduce and increase their survival rate. 

II. INTRODUCTION

Breaking the Surface, 2024 © Mollie Brown

Before the lower Snake River dams were built, the pristine, clear, cold waters of the Snake River Basin were home to millions of adult salmon and steelhead, along with sturgeon, lamprey eel, and other native fishes. The once-abundant anadromous fish populations in the Columbia-Snake River Basin (fish that hatch in freshwater, go to sea, and return to freshwater to spawn) are struggling to survive today primarily due to harms caused by the federal dams and their warming reservoirs. The federal hydro-system creates conditions that harm and kill both juvenile and adult fish, including by elevating water temperatures in large, stagnant reservoirs in the summer months. These cold-water fish begin to suffer harmful effects when water temperatures exceed 68° Fahrenheit.

Columbia-Snake River Basin salmon and steelhead populations are rapidly declining, and Southern Residents are also facing extinction due to a lack of their main food source–Chinook salmon. Only 74 individual orcas survive today. In Issue 11, we will report on Southern Resident orcas and the urgency to restore the lower Snake River through dam removal to bring salmon back to abundance along with restoring salmon habitats across the Columbia-Snake River Basin, and protecting marine habitats in order to protect Southern Residents from extinction.

During the summer, our Hot Water Report provides real-time water temperatures in the lower Snake and Columbia river reservoirs, with updates and reports from scientists, Tribal members, fishing guides, and other experts about the challenges facing these rivers, our opportunities to recover healthy, resilient fish populations, and the benefits they deliver to Northwest communities and other fish and wildlife populations.

View the Hot Water Report issues at wildsalmon.org/HWR

III. READING THE DATA - LOWER SNAKE AND COLUMBIA RIVER TEMPERATURES

INTRODUCTION TO THE WATER TEMPERATURE DATA:

• Throughout this summer, the Hot Water Report will provide, on a weekly basis, an update on real-time water temperatures in the lower Snake and Columbia River reservoirs.
• Hot water temperature effects to salmon: The longer and the higher water temperatures rise above 68°F "harm" threshold, the greater the harm to salmon, including: migration disruption, increased metabolism, increased susceptibility to disease, reduced reproductive potential (by reducing egg viability), suffocation (warm water carries less oxygen), and in worst case - death.
• Data collection: The daily average and high water temperature data at the four reservoir forebays are measured with sensors stationed at various depths below the reservoir surface, immediately upstream from the dams in the lower Snake River and the lower Columbia River for 2024. The water temperatures are taken on the hour. Hourly temperatures are used to find the highest temperatures reached in each reservoir, and hourly temperature measurements are used to find the daily average temperatures.
• Average Water Temperature Graphs (below): Daily average temperatures are represented with solid lines, and the 10-year average (2014 - 2023) temperatures are with dashed lines of the same color. The dotted line across the graph represents the 68°F “harm threshold” for adult and juvenile fish.
• Weekly High Water Temperature Tables (below): This table outlines the highest water temperatures reported for each reservoir during the week and how many days water temperatures have exceeded 68°F.

IV. DISCUSSION OF DATA - LOWER SNAKE AND COLUMBIA RIVER TEMPERATURES

LOWER SNAKE RIVER WATER TEMPERATURES: 8/30 - 9/7

Lower Snake River Water Temperatures - 2024 Daily Average and 10-year Average. Click on the image to view the graph and click here to view the PDF version with separate graphs for each reservoir.

Lower Snake River - 2024 Daily Average and 10-year Average.

• Lower Snake River Water Temperatures: this week, the Ice HarborDam's reservoir experienced a high average water temperature of 69.49°F on August 30.
• The Lower MonumentalDam's reservoir registered a high average temperature of 68.30°F on September 5.
• The Little GooseDam’s reservoir registered an average temperature of 67.94°F on August 30.
• The Lower Granite Dam's reservoir registered an average of 67.38°F. Lower Granite Dam’s reservoir’s average and high daily temperatures registered below 66°F due to the US Army Corps of Engineers’ continued cold water release effort from the reservoir behind Dworshak Dam’s Reservoir in the Clearwater River, a tributary to the lower Snake River. However, the benefits of this cold water infusion are limited. The presence of the dams prevents this cold water from entering the three downstream reservoirs. With a free-flowing lower Snake River, the additional benefit of cold waters released from the Dworshak reservoir will extend down the lower Snake River to its confluence with the Columbia River in south-central Washington State.

WEEKLY HIGH TEMPERATURES IN THE LOWER SNAKE RIVER: 8/30 - 9/7

• Many of the lower Columbia and Snake river reservoirs continue to reach above the 68°F “harm” threshold, for over 60 days.
• The Ice Harbor Dam's reservoir registered the highest temperature of 69.62°F on August 30.
• Lower Monumental Dam’s reservoir registered a high water temperature of 68.45°F on September 5.
• The Little Goose Dam's reservoir reached the highest water temperature of 68.56°F on September 5.
• The Lower Granite Dam's reservoir registered a high water temperature of 67.91°F.
• Water temperatures in the Lower Monumental Dam’s reservoir has exceeded 68°F for 61 days, Ice Harbor Dam's reservoir has exceeded 68°F for 60 days, and Little Goose Dam's reservoirs have exceeded 68°F for 56 days.

LOWER COLUMBIA RIVER WATER TEMPERATURES:  8/30 - 9/7

Lower Columbia River - 2024 Daily Average and 10-year Average.

Lower Columbia River Water Temperatures - 2024 Daily Average and 10-year Average. Click on the image to view the graph and click here to view the PDF version with separate graphs for each reservoir.

• Lower Columbia River Water Temperatures: this week, all four reservoirs on the lower Columbia River exceeded 68°F.
• The reservoir behind John Day Dam had a high average temperature of 70.34°F on September 7. The reservoir behind The Dalles Dam reached an average temperature of 69.98°F on September 6 and 7.

WEEKLY HIGH TEMPERATURES IN THE LOWER COLUMBIA RIVER: 8/30 - 9/7

• This week, on the lower Columbia River, the John Day Dam’s reservoir reached the highest temperature at 70.88°F.
• Bonneville Dam reservoir has spent 64 consecutive days above 68°F, and both The Dalles Dam and John Day Dam reservoirs registered above 68°F for 63 days.

Data Sources: The 2024 lower Snake River and lower Columbia River water temperature data presented in the Hot Water Report are collected from the USGS, Columbia River DART program by Columbia Basin Research, University of Washington, using data courtesy of the U.S. Army Corps of Engineers (USACE). The 10-year average water temperature data is courtesy of the Fish Passage Center. Lower Monumental 10-year average water temperatures are unavailable. Graphs and tables are assembled by SOS Staff.

V. ​​Critically endangered Southern Resident orcas need more Chinook salmon

K25 with a salmon © Monika Wieland Shields

Highly social and intelligent Southern Resident orcas have roamed the coastal waters of the Pacific Northwest and have held cultural and spiritual significance for Northwest Tribes since time immemorial. The three Southern Resident orca pods – J, K, and L– have historically fed on an abundance of large, fatty Chinook salmon. However, today, Columbia-Snake River Basin Chinook salmon populations are rapidly declining, and Southern Residents are also facing extinction due to a lack of food. Only 74 individual orcas survive today (according to the Center for Whale Research’s annual census of the Southern Resident population completed in January 2024).

Scientists agree there is an urgent need to remove the four lower Snake River dams to restore Snake River salmon runs, restore salmon habitats across the Columbia-Snake River Basin, and protect marine habitats in order to increase Southern Residents’ ability to reproduce and increase their survival rate.

Who are the Southern Residents orcas?

The three Southern Resident orca pods, known as J, K, and L pods, are a genetically and culturally distinct population unlike other orca communities found within the Pacific Northwest. Southern Residents communicate using their own exclusive dialect, typically traveling in large, extended family groups led by matriarchs, and stay in these extended family groups their entire lives. Historically, Southern Residents traveled, foraged, and socialized throughout the inland waters of the Salish Sea from late spring through late summer feeding on Chinook salmon.¹

Columbia-Snake River Basin salmon importance to Southern Resident orcas

L84 with a salmon Sept. 29 2011. Photo by Dave Ellifrit of the Center for Whale Research

Southern Residents are the original fishers of the Pacific Northwest waters, co-evolving over millennia with their preferred prey, Chinook salmon. Chinook salmon are the primary food source for the endangered Southern Residents, accounting for 50%-100% of their diet depending on the season. The Columbia-Snake River Basin and the Fraser River are the two most important sources of salmon for these orcas, where Columbia-Snake River Basin Chinook salmon account for more than half of the Chinook consumed by the orcas during the winter while they’re in coastal water.²

Southern Resident orcas are listed as endangered in both the U.S. (listed in 2005) and Canada (listed in 2003). The lack of Chinook salmon is the single greatest threat to the survival of the Southern Resident orcas. In 2016, the National Oceanic and Atmospheric Administration (NOAA) identified Southern Resident orcas as one of eight species most likely to go extinct in the near future unless immediate action is taken.

Data from the Center for Whale Research has shown that Southern Resident mortality is correlated with coast-wide Chinook salmon abundance. Drone research from SR3 has shown that Southern Residents are sometimes visibly thin, and a study from the U.W. Conservation Canine program discovered a 69% miscarriage rate primarily due to lack of food. This research indicates that restoring salmon for Southern Residents should be our top priority.

In 2018, NOAA Fisheries and Washington Department of Fish and Wildlife (WDFW) developed a list of Chinook salmon stocks identified as important to Southern Residents’ survival and required priority actions to increase critical prey for these orcas. Snake River Spring/Summer Chinook and Snake River Fall Chinook, as well as many Columbia-Basin salmon runs, are ranked in the top 10 Priority Chinook stocks for orca recovery.

Despite years of recovery efforts to restore Southern Residents and salmon, they both teeter on the brink of extinction. As fewer salmon return to the ocean, these iconic orcas are starving, and their population has declined to a record low – only 74 individuals are alive today – 25 in J Pod, 15 in K Pod, and 34 in L Pod (according to the Center for Whale Research’s annual census of the Southern Resident population completed in January 2024).

Hope for Southern Residents informed by Bigg’s orcas' recovery journey

The Southern Residents and Bigg’s orcas frequent the same waters in the Salish Sea and along the Pacific Coast. They are still considered the same species but are different ecotypes, meaning they are two distinct types of orcas that differ in size, appearance, pod structure, diet, behavior, culture, acoustics, and genetics.^3,4

As much as they are different, Bigg’s orcas and Southern Residents encounter the same threats, including pollution, noise and disturbances, and both have a history of being captured for display, which all have impacted their population.

Both Bigg’s orcas (listed as threatened in Canada) and Southern Residents experience the same threats; however, Bigg’s are thriving, overcoming threats, and increasing in population size. Why?

Research conducted by Orca Behavior Institute shows how abundant food sources are key to healthy orca populations, and with enough food, they are able to overcome threats and live healthier lives.

The Southern Residents have a very long history and knowledge of foraging for salmon in the Salish Sea and along the Pacific Coast, where Columbia-Snake River Basin Chinook salmon account for more than half of the Chinook provide Southern Residents’ winter diet.⁵

Since the decline of Chinook salmon, each of the Southern Resident pods have shifted their presence along their historical foraging range based on Chinook salmon runs.^6,7 According to Orca Behavior Institute data with reports from Pacific Whale Watch Association, Orca Network, and other sighting groups and community scientists, there was a 24% decline in Southern Resident sightings in 2023 compared to 2022, with a particularly noticeable drop in the summer and fall. 20 years ago, the Southern Residents were spending an average of more than 80 days in the Salish Sea in the months of June through August. For 2019-2023, that average has dropped to just 20 days.

For Southern Residents, the lack of salmon is by far the single greatest threat to their survival. For example, in the context of encountering pollution, when Southern Residents are not getting enough to eat, they are more susceptible to metabolizing their fat stores, releasing pollutants that circulate through their body, which makes them immune compromised.⁸ With the pollutants and lack of food in their bodies, it makes it harder to forage for food, and overall their quality of life declines.

In contrast, Bigg's absorb more toxins because the food (seals and seal lions) they eat are higher in the food web, but they are still healthier because they get enough to eat and therefore don't need to metabolize fat stores. Bigg’s population size continues to double due to finding enough food, and have been increasingly using the Salish Sea over the last 30 years, as shown in the annual Bigg’s sighting map above, where a total of 1413 sightings of Bigg’s were seen in 2023.

Contrasting the Bigg’s and Southern Resident maps shows us that when we restore Chinook salmon for Southern Residents, they can live healthier longer lives and thrive similar to Bigg’s orcas, despite other threats they encounter.

Restoring a free-flowing lower Snake River to recover Southern Resident orcas and salmon

Tahlequah's Respair J35 and J57 © Britt Freda

Since time immemorial, Southern Residents have a deep interconnected relationship with salmon, in which salmon has heavily influenced Southern Residents’ culture, communication, and genetics.

However, today, orcas are finding less and less salmon in their traditional and historical foraging areas, causing Southern Residents significant stress about finding enough food for their pod and often becoming visibly thin. Their mortality is linked to not having enough Chinook salmon as well as not having enough strength to overcome other threats that they face.

Scientists have identified that Snake River salmon are among the priority Chinook salmon that are essential to the recovery of Southern Residents. It is critical for Southern Residents to feed on salmon throughout their entire foraging range and also throughout the entire year, especially in the winter and early spring when orcas move toward the mouth of the Columbia Basin.

Scientists agree that recovering Chinook salmon is essential for the recovery of Southern Residents. Key actions to help achieve abundant salmon include removing the four lower Snake River dams to restore Snake River salmon runs, restoring salmon habitats across the Columbia-Snake River Basin, and protecting marine habitats in order to increase Southern Residents’ ability to reproduce and increase their survival rate.

References:
1.Orca Action Month: Orca Facts
2, 5. Hanson MB, Emmons CK, Ford MJ, Everett M, Parsons K, Park LK, et al. (2021) Endangered predators and endangered prey: Seasonal diet of Southern Resident killer whales. PLoS ONE 16(3): e0247031. https://doi.org/10.1371/journal.pone.0247031
3. Whale and Dolphin Conservation: Meet the different types of orcas
4. Orca Conservancy: The killer whales of the Pacific Northwest
7. Shields MW. 2023. 2018–2022 Southern Resident killer whale presence in the Salish Sea: continued shifts in habitat usage. PeerJ 11:e15635 https://doi.org/10.7717/peerj.15635
8. Wild Orca (2022) Hot Water Report: Interview with Dr. Deborah Giles - Science and Research Director at Wild Orca

The Hot Water Report is a project of the Save Our wild Salmon Coalition, Association of Northwest Steelheaders, Columbia Riverkeeper, Earthjustice, Endangered Species Coalition, Idaho Conservation League, Idaho Rivers United, National Wildlife Federation, Natural Resources Defense Council, Northwest Sportfishing Industry Association, Orca Network, Sierra Club, Snake River Waterkeeper, and Wild Steelhead Coalition.

View previous Hot Water Report issues at wildsalmon.org/HWR

Sockeye salmon with lesions dying from hot water in the Columbia-Snake River Basin © Conrad Gowell
Welcome to the Hot Water Report 2024: Warming Waters in the Lower Snake and Columbia Rivers.

I. EXECUTIVE SUMMARY

• This summer, for approximately 60 days, all four reservoirs created by the lower Snake River dams have experienced temperatures exceeding 68°F “harm” threshold. Many of the reservoir waters reached between 70°F and 72°F for several weeks.
• The once free-flowing river has been transformed by the dams and their reservoirs now produce lethal high water temperatures and provide conditions that support toxic algal blooms–further threatening the survival and recovery of salmon and steelhead.
• Wild-origin returns of salmon to the Snake Basin are 0.1-2% of their historical abundance, with many populations at or below a Quasi-Extinction Threshold (QET), which signals adult Snake River salmon abundance are nearing absolute extinction, and the probability of recovery is low without substantial and immediate intervention.
• The science is clear: in its report published in Sept. 2022, NOAA states that restoring Snake River salmon and steelhead to healthy and abundant levels would require restoration of the lower Snake River and its migration corridor by breaching the four lower Snake River dams as part of a comprehensive suite of actions for the Basin.

II. INTRODUCTION

Shine and Flow II © Rachel Teannalach

During the summer, our Hot Water Report provided real-time water temperatures in the lower Snake and Columbia river reservoirs, and reported on the challenges facing these rivers, opportunities to recover healthy, resilient fish populations, and the benefits they deliver to Northwest communities and other fish and wildlife populations.

The final Hot Water Report issue for summer 2024 will review this year’s high water temperatures in the lower Snake and Columbia reservoirs and the number of days each of the reservoirs experienced above the 68°F threshold. Issue 12 will provide a brief update on the Quasi-Extinction Threshold for Spring/summer Chinook salmon and steelhead and the urgency to restore Snake River fish.

The four federal dams and their reservoirs on the lower Snake River are the single largest factor in preventing salmon from migrating safely to the Pacific and returning to spawning grounds to reproduce in viable numbers. Restoring a free-flowing Snake River by removing its four dams and replacing their services is essential to provide cold, clean, healthy water for salmon and steelhead, protect and recover these once-highly prolific fish populations, uphold our nation's promises to Tribes, and help feed the critically endangered Southern Resident orcas and other fish and wildlife species.

View the Hot Water Report issues at wildsalmon.org/HWR

III. INTRODUCTION TO THE DATA: Highest Water Temperatures in the Lower Snake and Columbia Rivers from July 1 - September 16, 2024.

From April 1 - September 10, 2024, the Hot Water Report reported water temperatures at the four reservoir forebays in the lower Snake River and the lower Columbia River. In the following tables, below, we present a summary of the highest water temperatures in 2024, the date of the highest temperatures, and the number of days each of the reservoirs reached above the 68°F “harm” threshold.

Hot water temperature effects to salmon: Snake River salmon and steelhead experienced another summer of hot, harmful water temperatures in the lower Snake River and the lower Columbia River. The longer and the higher water temperatures rise above 68°F (this threshold is the legal and biological limit scientists identify to protect salmon), the greater the harm to salmon, including: migration disruption, increased metabolism, increased susceptibility to disease, reduced reproductive potential (by reducing egg viability), suffocation (warm water carries less oxygen), and in the worst case - death.

IV. DISCUSSION OF DATA: LOWER SNAKE AND COLUMBIA RIVER TEMPERATURES

HIGHEST WATER TEMPERATURES IN THE LOWER SNAKE RIVER: July 1 - September 16, 2024

• Hot water temperatures on the lower Snake River: This summer, for approximately 60 days, all four reservoirs created by the lower Snake River dams have experienced temperatures exceeding 68°F. Many of the reservoir waters reached between 70°F-72°F for several weeks. Depending on salmon species, migration for salmon and steelhead stops altogether when water temperatures reach 72-73°F. Salmon that have stopped or slowed their migration can languish for days or weeks in warm water and die from thermal stress and disease.
• On August 5, 2024, the reservoir behind the Lower Granite Dam registered the highest water temperature recorded this summer – 72.52°F, more than 4 degrees above the 68°F “harm” threshold. The Lower Granite Dam’s reservoir registered above 68°F for 20 days.
• Ice Harbor Dam's reservoir registered the highest water temperature of 72.50°F on August 10 and registered above 68°F for 69 days. 
• Little Goose Dam's reservoir reached the highest water temperature of 71.87°F on July 16, and the reservoir registered above 68°F for 56 days.
• Lower Monumental Dam’s reservoir registered a high water temperature of 71.53°F on July 24, and the reservoir registered above 68°F for 61 days.
• Cool water from Dworshak Reservoir provides cold water to Lower Granite Reservoir: The Lower Granite Reservoir registered above 68°F for 20 days, fewer days compared to the other reservoirs, due to the US Army Corps of Engineers’ cold water release effort from the reservoir behind Dworshak Dam in the Clearwater River, a tributary to the lower Snake River. The goal of this release is to lower water temperatures and aid salmon and steelhead survival, but the benefit of this cold water does not last long in the summer heat and does not cool the other three downstream reservoirs on the lower Snake. According to scientists at the Environmental Protection Agency (USEPA), with a free-flowing lower Snake River, cold water releases from Dworshak Dam during the summer months would further help keep temperatures cool and healthy for fish from Lewiston (ID) downstream to where the Snake River joins the Columbia River in south-central Washington State near the Tri-Cities.

HIGHEST WATER TEMPERATURES IN THE LOWER COLUMBIA RIVER: July 1 - September 16, 2024

• Hot water temperatures on the lower Columbia River: On July 21, 2024, the reservoir behind the John Day Dam registered the highest temperature recorded this summer – 72.68°F over 4 degrees above the 68°F “harm” threshold.
• The water temperatures in the four reservoirs created by dams on the lower Columbia River give us an in-depth look at the lethal conditions and temperatures that many Columbia Basin salmon and steelhead must now migrate through in the summer months. Endangered Snake River fish must traverse a total of eight stagnant reservoirs and their fish ladders/fish passages on their migration to the ocean as juveniles and again on their journey back upstream as adults. For instance, as adults migrate through the lower Columbia River dams, they are faced with hot water temperatures between 68 - 72°F and must continue to migrate through four other hot and stagnant reservoirs in the lower Snake River.

Data collection: The high water temperature data at the four reservoir forebays are measured with sensors stationed at various depths below the reservoir surface, immediately upstream from the dams in the lower Snake River and the lower Columbia River. Hourly temperatures are used to find the highest temperatures reached in each reservoir.  Data Sources: Water temperature dataare collected from the USGS, Columbia River DART program by Columbia Basin Research, University of Washington, using data courtesy of the U.S. Army Corps of Engineers (USACE). The 10-year average water temperature data is courtesy of the Fish Passage Center. Lower Monumental 10-year average water temperatures are unavailable. Graphs and tables are assembled by SOS Staff.

V. Urgency to restore the lower Snake River and to recover its native fish

Free Flowing III 2023, acrylic and graphite on birch panel 24" x 48" x 1.5" © Britt Freda

For millennia, wild Snake and Columbia River salmon and steelhead have delivered vast cultural, economic, nutritional, and ecological benefits to the people, fish, and wildlife of the Northwest. Before the lower Snake River dams were built, the pristine, clear, cold waters of the Snake River Basin were home to millions of adult salmon and steelhead, along with sturgeon, lamprey eel, and other native fishes. Each year, salmon and steelhead return from the Pacific Ocean, swimming against the current in search of their natal spawning gravels and delivering many millions of pounds of high-quality marine-derived nutrients to the landscape and wildlife of the Northwest.

Salmon and steelhead require clean, cold water, and free-flowing rivers for successful migration, spawning, and rearing. However, the once free-flowing river has been transformed by the dams and their reservoirs now produce lethal high water temperatures that significantly reduce access to the cold water, high-quality spawning, and nursery habitat that are essential for fish sustainability.¹ Since the completion of the dams on the lower Snake River, wild Snake River fish returns have plummeted and are far below the levels required to delist them from the Endangered Species Act, much less meet their recovery goals necessary to achieve healthy and abundant levels.

Hot Water Temperatures and Toxic Algal Blooms in the Lower Snake River

Toxic algal blooms in Lower Granite Reservoir on the Snake River.  Photos taken on September 1, 2024.

The lower Snake River dams create stagnant reservoirs, which are large, slow-moving pools that absorb enormous amounts of solar radiation, causing water temperature to reach lethally high levels. The reservoirs warm during the summer months and create a block of slow-moving hot water that retains the heat through the night and does not cool only until air temperatures drop. Fish ladders are the only route past the dams that Snake River salmon and steelhead have to enter. These ladders frequently contain water that is warmer than the average river temperature, and such conditions can create or exacerbate migration blockages, reducing salmon survival.

These warming waters in the lower Snake River reservoir inundate and destroy diverse micro-habitats that healthy rivers support, including cold-water refuges that salmon and steelhead rely upon during summer migrations. Without these vital pockets of cold water, salmonids cannot rest and recover on their journeys – adults moving upstream to spawn and juveniles moving downstream to the ocean.

This summer, many of the reservoirs behind the lower Snake River dams reached high temperatures between 71-72°F – above the biological and legal threshold scientists identified to protect salmon from lethal water temperatures. In late July, many Snake River sockeye have been observed this summer seeking refuge from hot water temperatures in the lower Snake River by moving (straying) into the Mid-Columbia River, where water temperatures are cooler.

The lower Snake River dams, their reservoirs, and fish ladders impact fish in many ways, including by elevating water temperatures that destroy and degrade habitat required for salmon and steelhead’s key life stages. For the second consecutive year in a row, the lower Snake River dams’ warming and stagnant reservoirs are providing conditions that support toxic algal blooms.

Since August 16, 2024, Whitman County Public Health has continued to collect toxic algal bloom samples along the lower Snake River. All water samples have tested positive for toxic algae with microcystins, a liver toxin, causing the river to become unsafe and dangerous to people, pets, communities, the environment, and native fish.

Endangered Snake River salmon and steelhead must now attempt to migrate through an increasingly sick lower Snake River, with dangerously high water temperatures and large toxic algal blooms—further threatening their survival and recovery.

Snake River Salmon and Steelhead on the Brink of Extinction

Figure 1. Over half the historical populations are extinct, and none of the existing populations are considered healthy and harvestable. Less than half of the 117 historical populations remain. Source: Nez Perce Department of Fisheries Resources Management.

Salmon runs have plummeted since the signing of the treaties and reservation executive orders that would protect the Tribes’ harvest rights.² Many of the Columbia-Snake River Basin salmon runs have been locally extirpated. Thirteen populations, including all four Snake River populations, are listed as threatened or endangered under the Endangered Species Act and remain at risk of extinction(Figure 1).

Wild-origin returns of salmon to the Snake Basin are 0.1-2% of their historical abundance, with many populations at or below a Quasi-Extinction Threshold (QET)—50 or fewer natural-origin spawners on the spawning grounds for 4 consecutive years.^3,4 Quasi-Extinction Threshold signifies that adult salmon and steelhead abundance in a population are nearing absolute extinction, and the probability of recovery is low without substantial and immediate intervention.

The Nez Perce Department of Fisheries Resources Management released an update on their Snake Basin Chinook and Steelhead Quasi-Extinction Threshold Alarm analysis:

Snake River Spring/Summer Chinook:

• As of the 2023 return, 17% or 6 out of the 35 populations in the Snake River Basin are currently meeting the QET.
• 13 or 37% of these populations below 50 spawners in 2023.
• The Nez Perce Department of Fisheries Resources Management is projecting that nearly 57% of these populations, 20 out of the 35, are predicted to be at or below 50 or fewer natural origin fish before 2028.

Snake River steelhead:

• As of the 2023 return, 19% or 4 out of the 21 populations in the Snake River Basin the QET in four consecutive years of 50 or fewer natural-origin spawners.
• 4 or 19% of these populations below 50 spawners in 2023.
• The Nez Perce Department of Fisheries Resources Management is projecting about 38% or 8 out of the 21 populations are predicted to be at or below 50 or fewer natural origin fish before 2028.

The Snake and Columbia River Basin contains some of the very best available habitat for salmon populations to recover to any significant level of abundance. However, with predictions pushing the populations below 50 spawners, the four lower Snake River dams are a major factor preventing salmon from reaching spawning grounds and reproducing in viable numbers.

Recovering Healthy, Abundant, and Harvestable Salmon and Steelhead Populations

Figure 2. Snake Basin salmon and steelhead current abundance (black dots) relative to historical abundance and Columbia Basin Partnership (CBP) goals; Columbia Basin Partnership high-range goals 5 – 31% of historical. All but one stock is below low-range goals. Fall Chinook salmon are above low-range but below mid-range goals. Source: Nez Perce Department of Fisheries Resources Management.

Over the past several decades, these fish have returned annually far below the recovery goals necessary to remove them from the protections of the Endangered Species Act.

The Columbia Basin Partnership (a diverse group of 31 Columbia Basin stakeholders and sovereigns, including Columbia Basin Tribes; representatives of the four Columbia Basin states (Washington, Oregon, Idaho, and Montana); ports, hydropower interests and public power entities; irrigators; transportation representatives; commercial and recreational fishers and conservationists convened by NOAA) released a set of recovery goals and common vision for the Basin and its salmon and steelhead to ensure that healthy runs of salmon and steelhead thrive into the future. The Partnership unanimously defined “recovery” to mean healthy, abundant, and harvestable naturally reproducing populations of salmon and steelhead, in which naturally produced fish need to meet the recovery goals established by the Partnership (Figure 2) – roughly five times the number needed to lift Endangered Species Act protections.⁵

Despite decades of failed mitigation efforts and many billions of dollars in recovery spending, these fish remain on the edge of extinction. An analysis of the actions necessary to achieve healthy and abundant salmon and steelhead completed by the National Oceanic and Atmospheric Administration (NOAA) Fisheries, Rebuilding Interior Columbia Basin Salmon and Steelhead, reports for Snake River stocks, the centerpiece action is restoring the lower Snake River via dam breaching, along with a comprehensive suite of other actions.

Salmon and steelhead—and endangered Southern Resident orcas and other fish and wildlife that highly depend on salmon—are running out of time. At this moment, we have an urgent opportunity to restore ecosystem health across the Basin and recover salmon and steelhead by removing the four lower Snake River dams and replacing the dams’ services. We must deliver a comprehensive solution to restore a healthy and resilient lower Snake River, protect the Northwest native fish from extinction, and uphold our nation's promises to Tribes by reconnecting this emblematic fish to 5,500 miles of pristine, protected river and streams in Idaho, Oregon, and Washington.

References:
1. American Fisheries Society (AFS) and the Western Division AFS (WDAFS): Statement about the Need to Breach the Four Dams on the Lower Snake River
2, 3. Tribal Circumstances Analysis developed by the Department of Interior, in collaboration and coordination with the Columbia Basin Tribes.
4. Nez Perce Department of Fisheries Resources Management: Snake Basin Chinook and Steelhead Quasi-Extinction Threshold Alarm
5. Trout Unlimited: What does salmon and steelhead “recovery” mean and who decides?

The Hot Water Report is a project of the Save Our wild Salmon Coalition, Association of Northwest Steelheaders, Columbia Riverkeeper, Earthjustice, Endangered Species Coalition, Idaho Conservation League, Idaho Rivers United, National Wildlife Federation, Natural Resources Defense Council, Northwest Sportfishing Industry Association, Orca Network, Sierra Club, Snake River Waterkeeper, and Wild Steelhead Coalition.

View previous Hot Water Report issues at wildsalmon.org/HWR

Sockeye salmon with lesions dying from hot water in the Columbia-Snake River Basin ©Conrad GowellWelcome to the Hot Water Report 2024: Warming Waters in the Lower Snake and Columbia Rivers. 

I. EXECUTIVE SUMMARY

• For decades, summer water temperatures in the lower Snake and Columbia rivers have been rising to levels that are lethal to salmon and steelhead.
• The frequency, magnitude, and duration of elevated high water temperature events in the river have increased with climate change and are exacerbated by the dams in the Columbia-Snake River Basin.
• Snake River salmon and steelhead populations suffer the highest mortality rates compared to other fish that spawn lower in the watershed and encounter fewer dams and reservoirs. Snake River salmon and steelhead encounter 8 dams and reservoirs - twice, in each direction - to successfully complete their anadromous lifecycle.
• Despite fluctuating ocean environments and influences due to a changing climate, scientists have consistently found that dam removal will significantly increase the survival and abundance of Spring Chinook and other salmon to achieve healthy and harvestable recovery goals that have been identified by regional tribes, stakeholders, and state and federal agencies.
• Scientists have determined that breaching the four lower Snake River dams is essential for avoiding extinction and would greatly improve the ability of migrating fishes to access these high-elevation, groundwater- and snowmelt-fed freshwater refuges, increasing their survival and productivity.

 II. INTRODUCTION

Pilgrimage, 2020, acrylic painting on birch panel, 24" x 30" © Josh Udesen

Many once-abundant anadromous fish populations—fish that hatch in freshwater, go to sea, and return to freshwater to spawn—in the Columbia-Snake River Basin are on the brink of extinction today due primarily to harms caused by federal dams and their warm, stagnant reservoirs. The Columbia-Snake federal hydro-system harms and kills both juvenile and adult fish in multiple ways, including by elevating water temperatures in its reservoirs in the summer months. These cold-water fish begin to suffer harmful effects when water temperatures exceed 68° F.

In Issue 2 of the Hot Water Report 2024, we correct the record misleading narratives that warming ocean conditions are the real obstacle to recovering healthy, abundant populations of Snake River salmon and steelhead. Snake River salmon and steelhead suffer the highest mortality rates, and lowest smolt-to-adult return ratios, compared to other fish that spawn lower in the watershed and encounter fewer dams and reservoirs.

Restoring a free-flowing Snake River by removing its four dams (and replacing their services) is essential to provide cold, clean, healthy water for salmon and steelhead, recover and protect these once-highly prolific fish populations from extinction, uphold our nation's promises to Tribes, and help feed critically endangered Southern Resident orcas.

During the summer, the Hot Water Report will provide real-time water temperatures in the lower Snake and Columbia river reservoirs, with updates and reports from scientists, Tribal members, fishing guides, and other experts about the challenges facing these rivers and our opportunities to recover healthy, resilient fish populations and the benefits they deliver to Northwest communities, and other fish and wildlife populations.

View the Hot Water Report issues at  wildsalmon.org/HWR

III. REMOVING THE LOWER SNAKE RIVER DAMS WILL RECOVER SALMON AND STEELHEAD

Northwest salmon and steelhead all swim in the same ocean; however, their mortality rates increase significantly with the number of dams and reservoirs they encounter during their migration. Endangered Snake River salmon and steelhead must traverse eight stagnant reservoirs created by federal dams as they migrate to the ocean and again on their journey back upstream as adults. Defenders of the status quo falsely claim that warming, unproductive ocean conditions - rather than the federal hydro-system - are the real obstacle to protecting and recovering healthy, abundant populations of Snake River salmon and steelhead. Yet, Snake River salmon and steelhead suffer the highest mortality rates, and lowest smolt-to-adult return ratios, compared to other fish that spawn lower in the watershed and encounter fewer dams and reservoirs.

Salmon and their ecosystems:

Freshwater: Salmon and steelhead require clean, cold water, intact rivers, and reliable streamflows for spawning, rearing, and migration. Before the dams were built, juvenile salmon were able to migrate quickly to the ocean - within a few days to several weeks - due to the swiftly moving currents of the Snake and Columbia rivers. Now, because of the harmful conditions created by the lower Snake River dams and their reservoirs, it takes often takes young fish more than a month to reach the ocean. According to scientists, Snake River fish that successfully reach the ocean, often arrive injured, energy-depleted, and weak, leading to 'delayed mortality' in the estuary and the ocean. The few fish that do survive and grow into adults will range in the ocean between one and six years. Adult salmon then return to spawn, and die, in the same river or stream where they were born. Steelhead are a little different; they have the ability to return to the ocean after they spawn and repeat this process one or more times–albeit this capacity has diminished due the number of dams and reservoirs they encounter on their journey.

In the Columbia-Snake Basin, the construction of the federal hydro system has profoundly degraded viable fish habitat and is the primary source of mortality for salmon and steelhead.

Saltwater: The ocean has a long-running and well-documented cyclic pattern of good conditions followed by bad conditions. Ocean conditions play a significant role in salmon and steelhead survival. When ocean conditions are good (abundant food availability for salmon and steelhead to eat), salmonid survival in the ocean increases, and we see increased survival of juvenile fish as they enter the ocean and increased adult salmon returns back into the Columbia-Snake Basin. When ocean conditions decline (reduced food availability), we often see adult salmon returns decline too.

How do we know the lower Snake River dams are a large source of mortality for Snake River fish?

We use the smolt-to-adult ratio - or SAR - to understand the percentage of ocean-bound juvenile fish that return as adults to spawn in freshwater.¹ SAR is the only metric that captures the cumulative impacts of the hydro-system on salmon and steelhead and thus indicates the sustainability of adult returns. In order to maintain current population levels, Snake River salmon must return consistently at a 2 percent SAR (meaning, for every 100 smolts that head out to the ocean, 2 adults must successfully return to spawn). According to regional Tribal, federal, and state scientists, rebuilding abundant, harvestable Snake River salmon and steelhead populations will require SARs between 4 and 6 percent (for every 100 smolts that head out to the ocean, 4 to 6 adults must successfully return to spawn).

After the completion of the four lower Snake River dams in 1975, SARs for Snake River Chinook salmon fell dramatically. Today, adult salmon return consistently below 1 percent and steelhead SARs average just over 1%. This decline in SARs below 1% represents a trajectory toward extinction as not enough smolts survive to maintain healthy population numbers over time.

Smolt-to-Adult Ratios (SARs) decrease as the number of dams and reservoirs fish encounter increase:

• Fish encountering 2 - 3 dams: Almost 7% of steelhead smolts from Oregon’s Deschutes River, who pass just two dams going and coming, successfully return as adults. More than 5% of Steelhead smolts from the John Day River, (three dams) return as adults, as do about 3.6% of Chinook smolts.
• Fish encountering 4 dams: On the Yakima River, about 4.5% of steelhead smolts return to spawn, as do a little over 2.7% of Chinook.
• Fish encountering 8 dams: Snake River salmon and steelhead encounter 8 dams and reservoirs - twice, in each direction - to successfully return as adults. On average, just 1.6% of these steelhead smolts return as adults, and only 0.76% of Chinook pass the Lower Granite Dam and complete the journey.

The more dams that anadromous fish populations must navigate, the lower the smolt-to-adult return ratio.

“The SARs tell the story that matters: passage through four dams or fewer allows SARs that equal maintaining and rebuilding salmon populations. Passage through eight dams yields SARs that point to imminent extinction.

Clearly, the fewer dams and the more juvenile salmon we can get to the ocean in good condition, the better chance we have of getting more adults back to their spawning grounds regardless of ocean conditions.”

–Rick Williams, Fisheries ecologist and Research Associate in the Department of Biology at The College of Idaho.

The cold, clean, high-elevation streams, just beyond the four lower Snake River dams, can serve as a safe haven for salmon in the face of climate change — if only the salmon can reach them. Stanley Lake in front of McGowan Peak. Sawtooth Mountains, Idaho. (Neil Ever Osborne / Save Our Wild Salmon / iLCP)

Does removing the four lower Snake River dams recover salmon and steelhead as climate change impacts continue?

Climate change has altered salmon and steelhead’s freshwater and saltwater ecosystems. As climate changes affect air temperatures, precipitation, snowpack, and wind patterns in the Pacific Northwest, it brings an increase of land and river heat waves, droughts, wildfires, and variations in river flow patterns.² The frequency, magnitude, and duration of elevated high water temperature events in the river have increased with climate change and are exacerbated by the dams in the Columbia-Snake River Basin. Dams and their reservoirs continue to elevate high water temperatures that impair salmon and steelhead survival and productivity and prevents salmon and steelhead from accessing cold clean water.

The science is clear: even with climate change impacts, the tributary habitat in the Snake River Basin will remain suitable for fish. The Snake River Basin currently contains 20% of the habitat occupied by salmon and steelhead in rivers of the Pacific Northwest; by 2080 it is forecast to contain 65% of the coldest, most climate-resilient stream habitats in the region.³ Scientists have determined that breaching the four lower Snake River dams would significantly improve the ability of migrating fishes to access these high-elevation, groundwater- and snowmelt-fed freshwater refuges, increasing survival and productivity in what will be an otherwise inhospitable future climate.⁴

“The basin’s native salmon and steelhead hover on the brink of extinction. Today, only 1-2% of historic wild salmon and steelhead return to the Snake River to spawn above the four lower Snake River dams. Climate change will continue to worsen the outlook for these coldwater species.

Ensuring access to this high-elevation habitat is the best opportunity to promote broad-scale population recovery in the face of warming waters.”

–Doug Austen, Executive Director of American Fisheries Society and Helen Neville, Senior Scientist at Trout Unlimited

Ocean environments fluctuate between good and bad conditions, and climate change is affecting the health of the ocean as well. Through modeling, scientists compared Spring Chinook returns with the dams in place and with removal of the lower Snake River dams under three ocean conditions: bad, average, and good.⁵ Under the model's dam removal scenario, Spring Chinook salmon increased in abundance and above healthy and harvestable recovery goals under all ocean conditions.

While addressing the health of the ocean and tackling climate change by dramatically reducing our fossil fuel consumption must be a top priority now and over time, it is also critical that we focus our efforts on effective, near-term solutions that will increase and improve salmon survival in their freshwater habitat. We may not be able to control the cyclical ocean conditions that salmon encounter, but we can restore health to the rivers they journey through on their way to and from the ocean. The science is clear: restoring the Snake River by removing the four lower Snake River dams is an essential action we must take as quickly as possible, or we will lose its wild salmon and steelhead populations - and miss one of our nation's great restoration opportunities - forever.

References:
1. Trout Unlimited: What is a smolt-to-adult ratio and why is it important?
2. National Oceanographic and Atmospheric Administration and National Marine Fisheries Service: Rebuilding Interior Columbia Basin Salmon and Steelhead
3, 4. Storch et al. 2022. A review of potential conservation and fisheries benefits of breaching four dams in the Lower Snake River (Washington, USA)
5. NMFS (National Marine Fisheries Service), 2020. A vision for salmon and steelhead: goals to restore thriving salmon and steelhead to the Columbia River basin. Phase 2 report of the Columbia River Partnership Task Force of the Marine Fisheries Advisory Committee.

IV. READING THE DATA - LOWER SNAKE AND COLUMBIA RIVER TEMPERATURES

Introduction to the water temperature data:

• Throughout this summer, the Hot Water Report will provide, on a weekly basis, an update on real-time water temperatures in the lower Snake and Columbia River reservoirs.
• The daily average and high water temperature data at the four reservoir forebays are measured with sensors stationed at various depths below the reservoir surface, immediately upstream from the dams in the lower Snake River and the lower Columbia River for 2024.
• Daily average temperatures are represented with solid lines and the 10-year average (2014 - 2023) temperatures with dashed lines of the same color.
• The dotted line across the graph represents the 68°F “harm threshold” for adult and juvenile fish.
• The longer and the higher these temperatures rise above 68°F, the greater the harm, including: migration disruption, increased metabolism, increased susceptibility to disease, reduced reproductive potential (by reducing egg viability), suffocation (warm water carries less oxygen), and in worst case - death.

V. DISCUSSION OF DATA - LOWER SNAKE AND COLUMBIA RIVER TEMPERATURES

AVERAGE LOWER SNAKE AND COLUMBIA RIVER TEMPERATURES: 6/26 - 7/2

Figure 1. Lower Snake River Water Temperatures - 2024 Daily Average and 10-year Average. Click on the image to view the graph.

Figure 2. Lower Columbia River Water Temperatures - 2024 Daily Average and 10-year Average. Click on the image to view the graph.Discussion of average water temperature data:

• Since April, temperatures in the lower Snake River and the lower Columbia River reservoirs have steadily increased.
• Figure 1. Lower Snake River Water Temperatures: this week, the reservoir behind the Lower Granite Dam reached a high average water temperature of 66.16°F on July 2 and has reached over their 10-year average.
• Figure 2. Lower Columbia River Water Temperatures: this week, the reservoirs behind the Bonneville Dam had a high average temperature of 65.66°F on July 1.
• As we begin the month of July, the water temperatures are below the 68°F “harm” threshold, which is good news for cold-water species like salmon and steelhead. However, we expect these temperatures will rise considerably in these reservoirs as the summer progresses.

WEEKLY HIGH TEMPERATURES IN THE LOWER SNAKE AND COLUMBIA RIVER: 6/26 - 7/2

• On the lower Snake River, the reservoir behind the Lower Granite Dam registered the highest water temperature of 66.51°F.
• On July 1, due to Lower Granite reaching high water temperatures above 66°F and nearing the 68°F “harm” threshold, the US Army Corps of Engineers announced the start of their annual summer release of cold waters from the Dworshak Reservoir in the Clearwater River, a tributary to the lower Snake River. The goal of this release is to lower water temperatures and aid salmon migration, but the benefit of this cold water does not last long in the heat of the summer and does not cool the other three downstream reservoirs on the lower Snake River. With a free-flowing river, the additional benefit of cold waters released from the Dworshak reservoir will extend all the way down the lower Snake River to its confluence with the Columbia River in south-central Washington State.

• On the lower Columbia River, the Bonneville reservoir registered the highest water temperature at 66.02°F.

Data Sources: The 2024 lower Snake River and lower Columbia River water temperature data presented in the Hot Water Report are collected from the USGS, Columbia River DART program by Columbia Basin Research, University of Washington, using data courtesy of the U.S. Army Corps of Engineers (USACE). The 10-year average water temperature data is courtesy of the Fish Passage Center. Lower Monumental 10-year average water temperatures are unavailable. Graphs and tables are assembled by SOS Staff.

 The Hot Water Report is a joint project of the Save Our wild Salmon Coalition, Association of Northwest Steelheaders, Columbia Riverkeeper, Earthjustice, Endangered Species Coalition, Idaho Conservation League, Idaho Rivers United, National Wildlife Federation, Natural Resources Defense Council, Northwest Sportfishing Industry Association, Orca Network, Sierra Club, Snake River Waterkeeper, and Wild Steelhead Coalition.

View previous Hot Water Report issues at wildsalmon.org/HWR

Sockeye salmon with lesions dying from hot water in the Columbia-Snake River Basin ©Conrad GowellWelcome to the Hot Water Report 2024: Warming Waters in the Lower Snake and Columbia Rivers.

I. EXECUTIVE SUMMARY

• Since the completion of the dams on the lower Snake River, salmon and steelhead have returned annually far below the recovery goals necessary to remove them from the protections of the Endangered Species Act and to achieve healthy and abundant levels.
• This week, on the lower Snake River, three reservoirs have registered high temperatures above the 68°F “harm” threshold. The reservoir behind the Little Goose Dam registered the highest water temperature of 69.53°F on July 9. 
• Given the current returns for wild Snake River Spring/Summer Chinook, steelhead, and sockeye, these fish have reached quasi-extinction thresholds – a critical threshold signaling they are nearing extinction, and without effective near-term intervention, many may not persist.

II. INTRODUCTION

A sockeye salmon (Oncorhynchus nerka) in Little Redfish Lake Creek, Sawtooth National Recreation Area, Idaho. © Neil Ever Osborne / Save Our wild Salmon / ILCP

The once-abundant anadromous fish populations of the Columbia-Snake River Basin are on the brink of extinction today due primarily to harm caused by federal dams and their warming reservoirs. The Columbia-Snake federal hydro-system harms and kills both juvenile and adult fish in multiple ways, including by elevating water temperatures in the summer months in large, stagnant reservoirs. These cold-water fish begin to suffer harmful effects when water temperatures exceed 68° Fahrenheit.

This week, on the lower Snake River, three reservoirs have registered high temperatures above the 68°F “harm” threshold. The reservoir behind the Little Goose Dam registered the highest water temperature of 69.53°F on July 9. In Issue 3, we’ll explore historical and 2023 wild Snake River salmon and steelhead returns and compare recent returns to established recovery goals – the annual adult returns deemed necessary to recover these populations and remove them from the Endangered Species Act list and achieve healthy and abundant levels.

Since the four lower Snake River dams were built over 60 years ago, Snake River salmon and steelhead returns have declined and remained far below the recovery goals necessary to sustain them over time and to remove them from the Endangered Species Act list and to achieve healthy and abundant levels. Without immediate and meaningful conservation actions, many scientists anticipate we will lose these fish forever.

During the summer, the Hot Water Report will provide real-time water temperatures in the lower Snake and Columbia river reservoirs, with updates and reports from scientists, Tribal members, fishing guides, and other experts about the challenges facing these rivers and our opportunities to recover healthy, resilient fish populations and the benefits they deliver to Northwest communities, and other fish and wildlife populations.

View the Hot Water Report issues at  wildsalmon.org/HWR

III. READING THE DATA - LOWER SNAKE AND COLUMBIA RIVER TEMPERATURES

INTRODUCTION TO THE WATER TEMPERATURE DATA:

• Throughout this summer, the Hot Water Report will provide, on a weekly basis, an update on real-time water temperatures in the lower Snake and Columbia River reservoirs.
• The daily average and high water temperature data at the four reservoir forebays are measured with sensors stationed at various depths below the reservoir surface, immediately upstream from the dams in the lower Snake River and the lower Columbia River for 2024.
• Average Water Temperature Graphs: Daily average temperatures are represented with solid lines and the 10-year average (2014 - 2023) temperatures with dashed lines of the same color. The dotted line across the graph represents the 68°F “harm threshold” for adult and juvenile fish.
• Weekly High Water Temperature Tables: This table outlines the highest water temperatures reported for each reservoir during the week and how many days water temperatures have exceeded 68°F.
• The longer and the higher these temperatures rise above 68°F, the greater the harm, including: migration disruption, increased metabolism, increased susceptibility to disease, reduced reproductive potential (by reducing egg viability), suffocation (warm water carries less oxygen), and in worst case - death.

IV. DISCUSSION OF DATA - LOWER SNAKE AND COLUMBIA RIVER TEMPERATURES

LOWER SNAKE RIVER AVERAGE TEMPERATURES: 7/3 - 7/10

Lower Snake River Water Temperatures - 2024 Daily Average and 10-year Average. Click on the image to view the graph.

• Lower Snake River Water Temperatures: this week, the reservoir behind the Lower Monumental reservoir reached a high average water temperature of 68.30°F on July 10. 
• The Little Goose Dam reached an average water temperature of 68.28°F on July 9 and has reached over their 10-year average of 67.40°F. The Ice Harbor reservoir reached an average temperature of 68.03°F on July 10. While average temperatures in the Lower Granite reservoir have not reached 68°F due to the US Army Corps of Engineers releasing cold water from the Dworshak Reservoir in the Clearwater River (see more info below), we expect these temperatures will rise considerably in these reservoirs in the upcoming weeks.

WEEKLY HIGH TEMPERATURES IN THE LOWER SNAKE RIVER: 7/3 - 7/10

• This week, on the lower Snake River, three reservoirs have registered high temperatures above the 68°F “harm” threshold. The reservoir behind the Little Goose Dam registered the highest water temperature of 69.53°F on July 9.
• Both Ice Harbor and the Lower Monumental Dam reservoirs registered the second highest water temperature of 68.72°F on July 10.

As air temperatures are increasing to near 100°F, the US Army Corps of Engineers announced their mitigation effort to release cold water from the Dworshak Reservoir in the Clearwater River (a tributary to the lower Snake River) to lower water temperatures and aid salmon migration in the lower Snake River. However, the benefits of this cold water infusion are limited. The presence of the dams prevents this cold water from entering the three downstream reservoirs. With a free-flowing lower Snake River, the additional benefit of cold waters released from the Dworshak reservoir will extend down the lower Snake River to its confluence with the Columbia River.

LOWER COLUMBIA RIVER AVERAGE TEMPERATURES: 7/3 - 7/10

Lower Columbia River Water Temperatures - 2024 Daily Average and 10-year Average. Click on the image to view the graph.

• Lower Columbia River Water Temperatures: this week, three reservoirs on the lower Columbia River reached water temperatures above the 68°F “harm” threshold. The reservoir behind the John Day Dam had a high average temperature of 69.62°F on July 9, exceeding its 10-year average temperature of 68.10°F.
• The Bonneville Dam reservoir reached a high average temperature of 69.08°F on July 9 and reached above its 10-year average temperature of 68°F. The Dalles reservoir reached a high water temperature of 68.54°F. The reservoir behind the McNary Dam has not yet reached the 68°F threshold.

WEEKLY HIGH TEMPERATURES IN THE LOWER COLUMBIA RIVER: 7/3 - 7/10

• On the lower Columbia River, the John Day reservoir registered the highest water temperature at 70.70°F. The lower Columbia River water temperatures exceeding 68°F imperils salmon and steelhead as they migrate through the stagnant reservoirs created by federal dams to reach the ocean and again on their journey back upstream as adults.

Data Sources: The 2024 lower Snake River and lower Columbia River water temperature data presented in the Hot Water Report are collected from the USGS, Columbia River DART program by Columbia Basin Research, University of Washington, using data courtesy of the U.S. Army Corps of Engineers (USACE). The 10-year average water temperature data is courtesy of the Fish Passage Center. Lower Monumental 10-year average water temperatures are unavailable. Graphs and tables are assembled by SOS Staff.

 V. Restoring Healthy and Abundant Snake River Wild Salmon & Steelhead

Chinook salmon back from the ocean. © Lynn Ketchum/Courtesy of Oregon State University

The Snake River's anadromous fish populations have been on a steady downward trajectory for decades. These salmon and steelhead face multiple obstacles, including increasingly hot water in the summer months in both the lower Snake and Columbia river reservoirs. Below, we present background information on the status of native fish returns, including (1) wild/natural Snake River sockeye (2) wild Snake River Spring/Summer Chinook, (3) wild steelhead. We will also look at how the historical and 2023 adult returns compare to established recovery goals – the annual adult fish returns deemed necessary to recover these populations to abundance and remove them from the Endangered Species Act list.

In summary - since the four lower Snake River dams were built, over 60 years ago, Snake River salmon and steelhead populations have steadily declined. Long before the dams were constructed, scientists projected the lower Snake River dams would devastate the last remaining robust wild salmon and steelhead population returning to the basin. Over the past several decades, these fish have returned annually far below the recovery goals necessary to remove them from the protections of the Endangered Species Act. Without immediate and meaningful conservation actions, scientists predict these populations will continue their decline toward extinction.

A. What Are Wild Salmon and Steelhead Returns?

The size and condition of a given population of salmon or steelhead are typically measured by the number of adult fish that return from the ocean to their upriver spawning grounds each year. The most straightforward method to measure the size of a salmon run is to count the fish as they swim upstream.

Snake River salmon and steelhead runs are counted at Lower Granite Dam, the last impediment on the river before the fish enter thousands of miles of tributary spawning and rearing habitat in central Idaho, Oregon, and Washington. Salmon returns have been counted on the lower Snake River since Ice Harbor Dam was first completed in 1962. This dataset of 60+ years, coupled with informed estimates of run sizes before the dams were constructed, provides valuable insight into the precipitous declines wild salmon and steelhead have experienced in the last 4-5 decades.

B. Historical Context

“Salmon runs have plummeted since the signing of the treaties and reservation executive orders that would protect the Tribes’ harvest rights. [...] Wild-origin returns of salmon to the Snake Basin are 0.1-2% of their historical abundance, with many populations at or below a quasi-extinction threshold.” – Historic and Ongoing Impacts of Federal Dams on the Columbia River Basin Tribes, Dept. of Interior (2024)

Historical data for the Columbia and Snake rivers indicate that 10-16 million wild adult salmon and steelhead entered the Columbia River Basin to spawn annually, with 2-6 million more utilizing the Snake River watershed.¹ The health of these populations has plummeted over time from historic levels that were once in the hundreds of thousands or millions, depending on the particular population.

Any enthusiasm today about a modest uptick in adult returns in a given year is a symptom of what scientists call “the shifting baseline syndrome,” where the perception of what constitutes a healthy population is based only on very recent reference points. These benchmarks today are extraordinarily low due to steep, long-term population declines. The result is that our collective perception of what constitutes a healthy salmon return continually shifts downward. Put simply, since the completion of the dams on the lower Snake River, nearly half of Snake River salmon and steelhead populations have reached quasi-extinction thresholds – a critical threshold signaling they are nearing extinction, and without immediate or near-term intervention, many may not persist, according to Nez Perce Tribe fishery scientists.

C. Recovery Goals for Healthy, Abundant, and Harvestable Salmon and Steelhead Populations

Recovery goals for wild Snake River salmon and steelhead have been set to reflect the healthy runs that returned to Idaho in the 1950s – before the dams were constructed. These goals represent self-sustaining, harvestable populations that scientists have determined the currently available, high-quality habitat in the Snake River Basin can support.

In 2020, the Columbia Basin Partnership - a diverse group of 31 Columbia Basin stakeholders and sovereigns, including Columbia Basin Tribes; representatives of the four Columbia Basin states (Washington, Oregon, Idaho, and Montana); ports, hydropower interests and public power entities; irrigators; transportation representatives; commercial and recreational fishers and conservationists convened by NOAA - released a set of recovery goals and common vision for the Basin and its salmon and steelhead to ensure that healthy runs of salmon and steelhead thrive into the future.

The Partnership unanimously defined “recovery” to mean healthy, abundant, and harvestable naturally reproducing populations of salmon and steelhead. To achieve cultural and economic stability provided by healthy salmon and steelhead stocks, many more naturally produced fish are needed to meet the recovery goals established by the Partnership – roughly five times the number needed to lift Endangered Species Act protections.²

Restoring the lower Snake River through dam removal is our most significant river and salmon restoration opportunity anywhere in the nation today. A restored, healthy and resilient lower Snake River is necessary to uphold our nation's promises to Tribes and restore healthy and abundant salmon and steelhead for future generations by reconnecting this emblematic fish to 5,500 miles of pristine, protected river and streams in Idaho, Oregon, and Washington.

D. Current Status of Wild Snake River Salmon and Steelhead Returns

(1) Snake River Sockeye: 

• Endangered Species Act Status: Endangered (listed in 1991)
• Historical Annual Return: Over 84,000
• Recovery Goal: 9,000 wild adults per year to the Stanley Basin
• 2023 Wild Returns: 31 wild/natural-origin sockeye returned to the Stanley Basin

Analysis: Historic runs to Idaho’s high mountain lakes used to be over 84,000+ sockeye per year, but they have severely declined over the years. In 1991, the Shoshone-Bannock Tribes successfully petitioned the federal government to list the run under the Endangered Species Act - making Snake River Sockeye the first ESA-listed salmonid in the Columbia Basin. According to the Idaho Fish and Game, in 1991, only four adult sockeye returned to the Sawtooth Basin. 23 sockeye returned between 1991-99, including two years when no sockeye returned.³

Snake River Sockeye have greater exposure to higher temperatures because they migrate in the summer when temperatures are hottest. In 2021, only 4 wild adult sockeye salmon survived and reached their spawning grounds in the Stanley Basin in central Idaho, after struggling past eight dams and warm, stagnant reservoirs.

In 2023, the Washington and Oregon Department of Fishery and Wildlife jointly reported a total Snake River Sockeye entering the Columbia was 1,999. Only 31 wild/natural Snake River Sockeye actually reached the Sawtooth Valley lakes (a unique and irreplaceable spawning ground for Snake River Sockeye).

Due to heat stress from hot water temperatures in the reservoirs of the lower Columbia and Snake rivers in 2023, 91% of the returning adult Snake River Sockeye that entered the mouth of the Columbia River died before spawning. Fishery scientists are predicting a similar decline of sockeye returns this year as a result of low returns entering the Columbia River and hot water temperatures in the lower Columbia and Snake Rivers.

At the beginning of July 2024, Oregon and Washington fisheries managers closed recreational fishing for all Columbia Basin sockeye in order to eliminate fishing impacts and protect ESA-listed Snake River Sockeye. The extremely depleted Snake River Sockeye are constraining important, valuable fishing opportunities in the lower Columbia River this summer where they are mixed with other, considerably more robust salmon populations that are running upstream at the same time. Snake River Sockeye are mixing in the lower Columbia River with a surprisingly robust return of adult sockeye swimming up the Columbia River to the Okanagon and Wenatchee Rivers. The initial pre-season forecast for these sockeye was 407,100, but was recently doubled by fisheries managers. In sharp contrast, the predicted return of Snake River Sockeye this year to the mouth of the Columbia River is just 3,800. Very few of these fish will survive to reach their spawning gravels high in the Stanley Basin of central Idaho.

(2) Snake River Spring/Summer Chinook:

• Endangered Species Act Status: Threatened (listed in 1992)
• Historical Annual Return: Over 1.5 million
• Recovery Goal: Escapement of 138,000 wild adults per year
• 2023 Wild Returns: 8,028
• Analysis: Spring/Summer Chinook were once the Pacific Northwest’s most widely distributed and abundant salmon, numbering in the millions. In the past five years, wild Snake River Spring/Summer Chinook numbers averaged less than half of their total return when the fish were first listed under the ESA in 1992. Snake River Spring/Summer Chinook remain far from the recovery goal (a minimum of 127K annually), and the population remains in long-term decline and at risk of extinction.⁴

(3) Snake River Steelhead:

• Endangered Species Act Status: Threatened (listed in 1997)
• Historical Annual Return: An estimated 600,000
• Recovery Goal: Escapement of 112,500 wild adults per year
• 2022/23 Returns: 13,631
• Analysis: The Snake River and its tributaries produced 55 percent of summer steelhead in the entire Columbia River Basin.⁵ However, today, wild steelhead are returning well below their recovery goal.

Given the current returns for wild Snake River Spring/Summer Chinook, steelhead, and sockeye, these fish are much closer to extinction than recovery. Each year, salmon and steelhead are returning far, far below their historical and recovery levels.

The four federal dams and their reservoirs on the lower Snake River continue to be the main obstacle to recovery. The rising temperatures caused by these stagnant reservoirs and reductions in snowpack in recent decades due to climate change are contributing to lower survival and reproductive success for already endangered salmon and steelhead.

Restoring this historic salmon river is essential for protecting these fish from extinction and rebuilding the many benefits they provide for the people of the Northwest and our nation.

Data Sources for the Idaho Rivers United’s ‘Snake River Wild Salmon Returns’ report: Fish Passage Center, Idaho Department of Fish and Game, and the Columbian Basin Partnership. Idaho Rivers United staff assembled the tables and graphs.

References:
1. Orca Action Month: Exploring the History of Salmon in the Columbia and Snake River Systems
2. Trout Unlimited: What does salmon and steelhead “recovery” mean and who decides?
3, 5. The Salmon Community’s View: The status of wild salmon and steelhead populations in the Columbia and Snake River Basin
4. Spokesman-Review: Helen Neville: The need to breach the Lower Snake River dams: A look at 2022 fish returns

The Hot Water Report is a joint project of the Save Our wild Salmon Coalition, Association of Northwest Steelheaders, Columbia Riverkeeper, Earthjustice, Endangered Species Coalition, Idaho Conservation League, Idaho Rivers United, National Wildlife Federation, Natural Resources Defense Council, Northwest Sportfishing Industry Association, Orca Network, Sierra Club, Snake River Waterkeeper, and Wild Steelhead Coalition.

View previous Hot Water Report issues at wildsalmon.org/HWR

Sockeye salmon with lesions dying from hot water in the Columbia-Snake River Basin © Conrad Gowell
Welcome to the Hot Water Report 2024: Warming Waters in the Lower Snake and Columbia Rivers.

I. EXECUTIVE SUMMARY

• All four lower Snake River reservoirs exceed the legal and biological limit of 68°F, which scientists have identified as critical for protecting salmon. The reservoir behind the Little Goose Dam registered the highest water temperature of 71.87°F on July 16, and the Ice Harbor Dam reservoir registered the second highest water temperature of 71.46°F on July 17.
• The longer salmon must swim through waters above 68°F, the greater the harm, including migration disruption, increased metabolism, increased susceptibility to disease, reduced reproductive potential (by reducing egg viability), suffocation (warm water carries less dissolved oxygen), and, in the worst case, death.
• Due to current heat stress and lethal reservoir heating, the Idaho Fish and Game Department is implementing an emergency program and rescue effort for Snake River Sockeye by capturing adults at Lower Granite Dam and trucking them to the Eagle Fish Hatchery near Boise ID.
• Scientists have consistently reaffirmed that the four lower Snake River dams must be removed to avoid the extinction of Snake River fish, restore them to abundant and harvestable levels, and provide new access for them to high-quality, resilient spawning habitat in a world experiencing worsening impacts of climate change. 

II. INTRODUCTION

Final Act © Amy GulickSnake River salmon today are migrating through dangerous and lethal water temperatures.This week, all four lower Snake River reservoirs have registered high temperatures above the 68°F “harm threshold". The reservoir behind the Little Goose Dam registered the highest water temperature of 71.87°F on July 16, and the Ice Harbor Dam reservoir registered the second highest water temperature of 71.46°F on July 17–both temperatures significantly exceed the legal (and biological) limit of 68°F, which scientists have identified as critical for protecting salmon.

In Issue 4, we’ll review different water temperatures and their effects on juvenile and adult salmon, and we'll reflect on the importance of restoring a free-flowing lower Snake River to provide cold, clean, and healthy waters for salmon and steelhead.

A restored, healthy, and resilient lower Snake River is an essential step to uphold our nation’s promises to Tribes - as it is necessary to sustain and rebuild healthy salmon populations for future generations by providing a cold, free-flowing river.

During the summer, the Hot Water Report will provide real-time water temperatures in the lower Snake and Columbia river reservoirs, with updates and reports from scientists, Tribal members, fishing guides, and other experts about the challenges facing these rivers, our opportunities to recover healthy, resilient fish populations, and the benefits they deliver to Northwest communities and other fish and wildlife populations.

View the Hot Water Report issues at wildsalmon.org/HWR

III. READING THE DATA - LOWER SNAKE AND COLUMBIA RIVER TEMPERATURES

INTRODUCTION TO THE WATER TEMPERATURE DATA:

• Throughout this summer, the Hot Water Report will provide, on a weekly basis, an update on real-time water temperatures in the lower Snake and Columbia River reservoirs.
• The daily average and high water temperature data at the four reservoir forebays are measured with sensors stationed at various depths below the reservoir surface, immediately upstream from the dams in the lower Snake River and the lower Columbia River for 2024. The water temperatures are taken on the hour. Hourly temperatures are used to find the highest temperatures reached in each reservoir, and hourly temperature measurements are used to find the daily average temperatures.
• Average Water Temperature Graphs (below): Daily average temperatures are represented with solid lines, and the 10-year average (2014 - 2023) temperatures are with dashed lines of the same color. The dotted line across the graph represents the 68°F “harm threshold” for adult and juvenile fish.
• Weekly High Water Temperature Tables (below): This table outlines the highest water temperatures reported for each reservoir during the week and how many days water temperatures have exceeded 68°F.
• The longer and the higher these temperatures rise above 68°F, the greater the harm, including: migration disruption, increased metabolism, increased susceptibility to disease, reduced reproductive potential (by reducing egg viability), suffocation (warm water carries less oxygen), and in worst case - death.

IV. DISCUSSION OF DATA - LOWER SNAKE AND COLUMBIA RIVER TEMPERATURES 

LOWER SNAKE RIVER AVERAGE TEMPERATURES: 7/11 - 7/17
Lower Snake River Water Temperatures - 2024 Daily Average and 10-year Average. Click on the image to view the graph and click here to view the PDF version with separate graphs for each reservoir.

• Lower Snake River Water Temperatures: this week, the reservoir behind the Ice Harbor Dam reached a high average water temperature of 71.15°F on July 17, exceeding its 10-year average of 70°F.
• The Lower Monumental reservoir reached an average temperature of 70.08°F on July 16. The Little Goose Dam reached an average water temperature of 70.08°F on July 17 and has reached over its 10-year average of 68.20°F.
• Lower Granite reservoir reached 68.34°F, above its 10-year average of 66.70. In the past weeks, the average temperatures in the Lower Granite reservoir stayed between 67- 68°F due to the US Army Corps of Engineers releasing cold water of 41-42°F from the Dworshak Reservoir; the Lower Granite reservoir’s hourly water temperature data reported a high temperature of 68.09°F on July 14 and 68.24°F on July 17.

WEEKLY HIGH TEMPERATURES IN THE LOWER SNAKE RIVER: 7/11 - 7/17

• This week, on the lower Snake River, all four reservoirs have registered high temperatures above the 68°F “harm” threshold. Little Goose Dam reservoir registered the highest water temperature of 71.87°F on July 16.
• The reservoir behind the Ice Harbor Dam registered the second highest water temperature of 71.46°F on July 17. Lower Monumental Dam reservoir registered the highest water temperature of 70.63°F on July 16.
• This week, Lower Granite Dam reached a high water temperature of 68.85°F on July 17. In previous weeks, Lower Granite Dam registered water temperatures from 66-67°F due to the Army Corps releasing cooler water from Dworshak Reservoir.

LOWER COLUMBIA RIVER AVERAGE TEMPERATURES: 7/11 - 7/17

Lower Columbia River Water Temperatures - 2024 Daily Average and 10-year Average. Click on the image to view the graph and click here to view the PDF version with separate graphs for each reservoir.
Lower Columbia River Water Temperatures - 2024 Daily Average and 10-year Average.

• Lower Columbia River Water Temperatures: this week, all four reservoirs on the lower Columbia River reached water temperatures above the 68°F “harm threshold." 
• This week, the John Day Dam reservoir reached a high average temperature of 70.88°F on July 17, exceeding its 10-year average temperature of 69.40°F.
• The reservoir behind the Bonneville Dam and The Dalles Dam had a high average temperature of 70.34°F on July 16 and July 17, exceeding its 10-year average temperature of 69.30 - 69.40°F. The reservoir behind the McNary Dam reached an average temperature of 69.98°F on July 17.

WEEKLY HIGH TEMPERATURES IN THE LOWER COLUMBIA RIVER: 7/11 - 7/17

• On the lower Columbia River, the John Day Dam reservoir registered the highest water temperature at 71.24°F on July 17. The lower Columbia River water temperatures exceeding 68°F imperil salmon and steelhead as they migrate through the stagnant reservoirs created by federal dams to reach the ocean and again on their journey back upstream as adults.

Data Sources: The 2024 lower Snake River and lower Columbia River water temperature data presented in the Hot Water Report are collected from the USGS, Columbia River DART program by Columbia Basin Research, University of Washington, using data courtesy of the U.S. Army Corps of Engineers (USACE). The 10-year average water temperature data is courtesy of the Fish Passage Center. Lower Monumental 10-year average water temperatures are unavailable. Graphs and tables are assembled by SOS Staff.

V. Salmon and Steelhead are in Hot Water

Lower Snake River Dam © EcoFlight

All eight lower Snake and Columbia River reservoirs have surpassed the 68°F “harm threshold" for salmon and steelhead. The reservoir behind Little Goose Dam registered the highest water temperature of 71.87°F on July 16, and the Ice Harbor Dam reservoir registered the second highest water temperature of 71.46°F on July 17—both temperatures significantly exceed the legal (and biological) limit of 68°F, which scientists have identified as critical for protecting salmon. Salmon and steelhead are in hot water.

Hot Water Temperatures and Their Impact on Salmon

Salmon require cold, clean water and freshwater habitat to thrive and complete their ancestral migration. The once free-flowing river has been transformed into reservoirs that produce lethal high water temperatures and significantly reduce access to the cold water, high-quality spawning, and nursery habitat that are essential for fish sustainability.¹

Reservoirs are large, slow-moving pools that absorb enormous amounts of solar radiation, causing waters to warm. The reservoirs warm during the summer months and create a block of hot water that retains its heat through the night until fall air temperatures drop. These hot waters inundate and destroy diverse micro-habitats that healthy rivers support, including cold-water refuges that salmon and steelhead rely upon during summer migrations. Without these vital pockets of cold water, salmonids struggle to rest and recover on their journeys—adults moving upstream to spawn and juveniles moving downstream to the ocean.

The lower Snake River dams and their reservoirs create hot waters, which results in lower survival and reduced reproductive success for salmon and steelhead. Rising temperatures and reductions in snowpack in recent decades due to climate change exacerbate these warming waters, worsening the conditions that further harm these fish.

The longer and higher water temperatures rise above 68°F, the greater the harm to salmon and steelhead, including migration disruption, increased metabolism, increased susceptibility to disease, reduced reproductive potential (by reducing egg viability), suffocation (warm water carries less dissolved oxygen), and, in the worst case, death.

For Snake River stocks, the centerpiece action is restoring the lower Snake River via dam breaching.

Breaching will reduce hydrosystem-caused mortality by decreasing travel time for juvenile fish to reach the Pacific Ocean, reducing fish/powerhouse encounters, reducing stress on juvenile fish associated with the hydrosystem that contributes to delayed mortality after reaching the ocean. By restoring the river, dam removal will provide 140 miles of historic rearing and spawning habitat.– National Oceanographic and Atmospheric Administration

Sockeye salmon with lesions from hot water in the Columbia-Snake River Basin, 2021 © Conrad Gowell

Below is a brief list of water temperature ranges suitable and lethal to salmon and steelhead:

• Although varying by species, life stage, and season, the optimal range for juvenile and adult salmon in this region is 55-64°F.² Studies have also indicated that all Snake River salmon species (sockeye, spring/summer Chinook, fall Chinook, and steelhead) experience reduced survival at elevated water temperatures above 64°F, depending on the timing of their upriver migration.³
• 68°F: Adult salmon have difficulty migrating upstream when water temperatures approach 68°F.⁴
• 69°F: As temperatures reach 69°F, salmon become sluggish.⁵ An increase of even a few degrees above the optimum range can change migration timing, reduce growth rates, reduce available oxygen, and increase susceptibility to parasites, predators, and disease.⁶ Warm water temperature can alter growth and development rates for juvenile salmon.⁷
• 70-71°F: Stream temperatures of 70°F and above are extremely stressful for most species,⁸ stress including concurrent thermal stress and energy depletion.⁹ Water temperatures of 70°F have been demonstrated to inhibit or stop migrating salmon and steelhead.¹⁰ As of July 2024, water temperatures are reaching between 68 - 71°F.
• 72-73°F: Migration stops altogether when water temperatures reach 72-73°F. Salmon that have stopped or slowed their migration, and languish for days or weeks in warm water, begin dying from thermal stress and disease.¹¹
• 77°F and above: If salmon are exposed to water above 77°F for more than 24 hours, they will die.¹²

Devastatingly low salmon and steelhead returns because of hot water temperatures

Scientists state excessively high water temperatures above 68°F are now normal for extended periods in July, August, and September in the lower Snake River. Major temperature-related fish deaths are occurring frequently during the summer months. Up to 70 percent of total out-migrating smolts are killed each year before they reach the ocean as a result of dam encounters, hot stagnant reservoirs, predation, energy depletion and extended travel time.¹³

• In the summer of 2015, 96 percent of the returning adult Snake River sockeye salmon run died prematurely (pre-spawn) in the lower Snake and Columbia rivers because the reservoirs, coupled with record air temperature and low flows, caused the water to become too warm.¹⁴
• In early July 2021, video footageshows heat-stressed sockeye salmon with large, open lesions and fungus returning to the Columbia and Snake rivers with temperatures exceeding 71°F, leading Oregon and Washington to order drastic emergency fishing closures. Only 4 wild/natural Snake River sockeye survived the hot water temperatures in the lower Snake and Columbia River and reached their spawning grounds in Sawtooth Valley lakes, Stanley basin in central Idaho.
• For 2023, the Washington and Oregon Departments of Fish and Wildlife officially estimated that 1,999 endangered Snake River Sockeye entered the Columbia River. But only 174 of those Sockeye actually reached the Sawtooth Valley lakes, and only 31 of those were wild/naturally-spawned. In other words, 91% of endangered Snake River Sockeye entering the Columbia last year died before reaching the Sawtooth lakes, which are the only place on earth that Snake River Sockeye spawn, more than 850 miles from the ocean and 6000 feet above sea level. Heat stress, particularly in 320 miles of unbroken dam-and-reservoir on the lower Columbia and lower Snake Rivers, is the main cause of this extremely high mortality.

This summer, Snake River salmon and steelhead have been migrating through the lower Columbia and Snake rivers with temperatures between 68°F - 71°F. Due to heat stress and lethal reservoir heating, the Idaho Fish and Game Department decided to implement an emergency rescue effort for Snake River sockeye by capturing adults at Lower Granite Dam and trucking them to the Eagle Fish Hatchery near Boise, ID.

Over $24 billion have been invested in salmon recovery programs in the Columbia/Snake Basin, including mitigation efforts such as removing the fish from the river and transporting them by truck and barge. However, according to scientists, the only permanent solution to protect Snake River salmon and steelhead from extinction: restore the lower Snake River by removing its four dams. This is more urgent now than ever before as the frequency, magnitude, and duration of elevated high water temperature events in the river have increased with climate change and are exacerbated by the dams in the Columbia-Snake River Basin.

Despite spending billions on ineffective recovery efforts, these species continue to decline, harming both aquatic and terrestrial ecosystems, other species, tribal rights, and commercial and recreational fishing communities.

Scientific studies consistently demonstrate that breaching the four lower Snake River dams will provide greater certainty of achieving long-term survival and recovery of native wild fishes more than any other measure or combination of measures without dam breaching. Breaching the dams to restore riverine habitats in the lower Snake River will also benefit ecosystem processes, entire biological communities, and increase climate change resilience of anadromous fishes. – American Fisheries Society (AFS) and the Western Division AFS

Salmon need cold, clean water

Salmon will continue to decline toward extinction unless we restore the lower Snake River by removing its dams and replacingtheir services. Salmon and steelhead desperately need a cold, free-flowing lower Snake River to ensure resilient and abundant salmon and steelhead populations thrive for future generations.

A published report by Columbia Riverkeeper – ‘Columbia Riverkeeper White Paper: Computer modeling shows that Lower Snake River dams caused dangerously hot water for salmon in 2015’ – confirms through computer modeling that a free-flowing lower Snake River would not absorb the same amount of solar radiation. The cooler waters of a free-flowing river would deliver benefits to migrating juvenile and adult salmon and steelhead populations—leading to increased survival and reproductive success.¹⁵ Another computer model from the Environmental Protection Agency shows that removing the four lower Snake River dams would reduce Snake River water temperatures by 6.3 degrees F, on average, during the summer and early fall.¹⁶

The science is clear: the four lower Snake River dams must be removed to avoid extinction of Snake River fish and restore them to abundant, harvestable levels; provide access to high quality, resilient spawning habitat in a world enduring worsening impacts of climate change; and honor our nation’s promises to Northwest Tribes.¹⁷

Restoring the lower Snake River by removing its four federal dams is an essential cornerstone for any credible regional salmon recovery strategy.

References:
1, 15. Statement of the American Fisheries Society (AFS) and the Western Division AFS (WDAFS) About the Need to Breach the Four Dams on the Lower Snake River
2, 6, 8. A Great Wave Rising: Solutions for Columbia and Snake River Salmon; McCullough, D.A., 1999. “A Review and Synthesis of Effects of Alterations to the Water Temperature Regime on Freshwater Life Stages of Salmonids, With Special Reference to Chinook Salmon.” Region 10 Water Resources Assessment Report No. 910-R-99-010
3. Letterto NW policymakers signed by 55 Fisheries and natural resource scientists.
4. EPA: Columbia and Lower Snake Rivers Temperature Total Maximum Daily load
7. National Wildlife Federation: How Water Temperatures affect salmon
5, 9. Poole, G., et al., 2001. Technical Synthesis: Scientific Issues Relating to Temperature Criteria for Salmon, Trout, and Char Native to the Pacific Northwest
10. Idaho Fisheries Resources Office, U.S. Fish and Wildlife Service, DOI Temperature and handling of adult salmon and steelhead at Bonneville Dam January 24, 2010
11, 14, 15, 16. Columbia Riverkeeper White Paper - Computer modeling shows that Lower Snake River dams caused dangerously hot water for salmon in 2015.
12. Columbia River Inter-Tribal Fish Commission: Climate Change
13. Save Our wild Salmon Press Release: Congressional field hearing ignores the urgency for protecting salmon from extinction and opportunity to invest in Northwest communities and infrastructure
17. Scientists’ letteron the need for lower Snake River dam removal to protect salmon and steelhead from extinction and restore abundant, fishable populations.

The Hot Water Report is a joint project of the Save Our wild Salmon Coalition, Association of Northwest Steelheaders, Columbia Riverkeeper, Earthjustice, Endangered Species Coalition, Idaho Conservation League, Idaho Rivers United, National Wildlife Federation, Natural Resources Defense Council, Northwest Sportfishing Industry Association, Orca Network, Sierra Club, Snake River Waterkeeper, and Wild Steelhead Coalition.

View previous Hot Water Report issues at wildsalmon.org/HWR

Sockeye salmon with lesions dying from hot water in the Columbia-Snake River Basin © Conrad Gowell
Welcome to the Hot Water Report 2024: Warming Waters in the Lower Snake and Columbia Rivers.

 I. EXECUTIVE SUMMARY

• All four lower Snake River reservoirs register temperatures above the 68°F “harm” threshold. Ice Harbor Dam reservoir was the warmest this week - at 72.28°F on July 23.
• The Idaho Department of Fish & Game (IDFG) reported on July 22 that significant numbers of Snake River sockeye have been observed seeking refuge from hot water in the lower Snake River by moving (straying) into the Mid-Columbia River, where temperatures are cooler.
• Scientific studies and computer models demonstrate that a free-flowing lower Snake River would absorb far less solar radiation compared to reservoirs with the dams in place. This would result in considerably cooler waters and deliver significant survival benefits to migrating juvenile and adult salmon and steelhead. Salmon can withstand some exposure to warm water. However, the longer the exposure and higher the temperatures, the greater the harms. Eliminating the four slack water reservoirs created by the lower Snake River dams would also shorten migratory travel time and energy expenditures, reduce overall exposure to hot water as well as harmful impacts from in-reservoir predation.

II. INTRODUCTION

Return 2021, acrylic painting on birch panel, 30" x 60 © Josh Udesen

The Columbia-Snake federal hydro-system harms and kills both juvenile and adult fish in multiple ways, including by elevating water temperatures in the summer months in their large, stagnant reservoirs. These cold-water fish begin to suffer harmful effects when water temperatures exceed 68°F.

All four lower Snake River reservoirs currently register temperatures above the 68°F “harm” threshold. Ice Harbor Dam reservoir registered the highest water temperature of 72.28°F on July 23. Lower Monumental Dam reservoir registered the second highest temperature at 71.53°F on July 24.

In this issue, we spotlight the emergency salmon transportation program recently begun by the Idaho Department of Fish and Game (IDFG) in an effort to protect critically endangered sockeye salmon from deadly hot water conditions in the lower Snake River reservoirs this summer. While this is an important project to improve this year’s returning adults’ survival by removing them from a lethal river, the science remains clear: protecting Snake River fish from extinction and rebuilding their populations to abundance in the long-term requires restoring a free-flowing lower Snake River.

During the summer, the Hot Water Report provides real-time water temperatures in the lower Snake and Columbia river reservoirs, with updates and reports from scientists, Tribal members, fishing guides, and other experts about the challenges facing these rivers, our opportunities to recover healthy, resilient fish populations, and the benefits they deliver to Northwest communities and other fish and wildlife populations.

View the Hot Water Report issues at wildsalmon.org/HWR

III. READING THE DATA - LOWER SNAKE AND COLUMBIA RIVER TEMPERATURES

INTRODUCTION TO THE WATER TEMPERATURE DATA:

• Throughout this summer, the Hot Water Report will provide, on a weekly basis, an update on real-time water temperatures in the lower Snake and Columbia River reservoirs.
• Data collection: The daily average and high water temperature data at the four reservoir forebays are measured with sensors stationed at various depths below the reservoir surface, immediately upstream from the dams in the lower Snake River and the lower Columbia River for 2024. The water temperatures are taken on the hour. Hourly temperatures are used to find the highest temperatures reached in each reservoir, and hourly temperature measurements are used to find the daily average temperatures.
• Average Water Temperature Graphs (below): Daily average temperatures are represented with solid lines, and the 10-year average (2014 - 2023) temperatures are with dashed lines of the same color. The dotted line across the graph represents the 68°F “harm threshold” for adult and juvenile fish.
• Weekly High Water Temperature Tables (below): This table outlines the highest water temperatures reported for each reservoir during the week and how many days water temperatures have exceeded 68°F.
• Hot water temperature effects to salmon: The longer and the higher water temperatures rise above 68°F, the greater the harm to salmon, including: migration disruption, increased metabolism, increased susceptibility to disease, reduced reproductive potential (by reducing egg viability), suffocation (warm water carries less oxygen), and in worst case - death.

IV. DISCUSSION OF DATA - LOWER SNAKE AND COLUMBIA RIVER TEMPERATURES 

LOWER SNAKE RIVER WATER TEMPERATURES: 7/18 - 7/24

Lower Snake River - 2024 Daily Average and 10-year Average.

Lower Snake River Water Temperatures - 2024 Daily Average and 10-year Average. Click on the image to view the graph and click here to view the PDF version with separate graphs for each reservoir.

• Lower Snake River Average Water Temperatures: this week, the reservoir behind the Ice Harbor Dam experienced a high average water temperature of 71.76°F on July 24, exceeding its 10-year average of 70.90°F.
• The reservoir behind Lower Monumental Damexperienced an average temperature of 71.15°F on July 24. 
• Little Goose Dam reservoir saw an average water temperature of 70.16°F on July 21 and July 24.
• Lower Granite reservoir saw an average water temperature of 68.07°F, above its 10-year average of 66.80°F. This week, the Lower Granite Dam's reservoir’s average also registered below 67°F from 7/19 - 7/22 due to the US Army Corps of Engineers' cold water releases from the reservoir behind Dworshak Dam.

WEEKLY HIGH TEMPERATURES IN THE LOWER SNAKE RIVER: 7/18 - 7/24

• The Ice Harbor Dam reservoir registered the highest water temperature of 72.28°F on July 23.
• Lower Monumental Dam reservoir registered the second highest temperature of 71.53°F on July 24.
• The Little Goose Dam reservoir registered a high temperature of 71.29°F on July 24.
• Lower Granite Dam reached a high water temperature of 68.83°F on July 18.  

LOWER COLUMBIA RIVER WATER TEMPERATURES:  7/18 - 7/24

Lower Columbia River - 2024 Daily Average and 10-year Average.

Lower Columbia River Water Temperatures - 2024 Daily Average and 10-year Average. Click on the image to view the graph and click here to view the PDF version with separate graphs for each reservoir.

• This week, all four reservoirs on the lower Columbia River experienced average water temperatures above the 68°F “harm" threshold.
• The reservoir behind the Bonneville Dam, The Dalles Dam, and John Day Dam had a high average temperature of 71.42°F on July 21, exceeding its 10-year average temperature.
• The reservoir behind McNary Dam reached an average temperature of 69.58°F on July 24.

WEEKLY HIGH TEMPERATURES IN THE LOWER COLUMBIA RIVER: 7/18 - 7/24

• On the lower Columbia River, the John Day Dam reservoir registered the highest water temperature at 72.68°F on July 21.
• The Dalles Dam reservoir reached the second highest water temperature at 71.78°F on July 21.

Data Sources: The 2024 lower Snake River and lower Columbia River water temperature data presented in the Hot Water Report are collected from the USGS, Columbia River DART program by Columbia Basin Research, University of Washington, using data courtesy of the U.S. Army Corps of Engineers (USACE). The 10-year average water temperature data is courtesy of the Fish Passage Center. Lower Monumental 10-year average water temperatures are unavailable. Graphs and tables are assembled by SOS Staff.

V. Removing dams will reduce lower Snake River water temperatures and deliver critical survival benefits to endangered salmon and steelhead

Water temperatures in the lower Snake River continue to rise between 68°F - 72°F, a range that causes significant harm to salmon, where they can experience reduced available oxygen; increase susceptibility to parasites, predators, and disease; alter growth and development rates for juvenile salmon; energy depletion, and a disruption in migration.

Map of the Mid-Columbia River and lower Snake RiverThe Idaho Fish & Game Department (IDFG) reported on July 22 that Snake River sockeye have been observed seeking refuge from hot water temperatures in the lower Snake River by moving (straying) into the Mid-Columbia River, where water temperatures are cooler. The Department reports, over the last two weeks, 15 PIT-tagged Snake River returning adult sockeye were observed at the Priest Rapids Dam on the mainstem Columbia River upstream from its confluence with the Snake River. Scientists estimate that approximately 16% of the total Snake River sockeye run detected earlier this year passing Bonneville Dam have ‘strayed’ into the Mid-Columbia River region because water temperatures there are cooler. To compare, on July 24, Priest Rapids forebay registered an average water temperature of 65.04°F, whereas Ice Harbor forebay average temperature is 71.76°F - a substantial difference of more than 6°F.

Emergency Sockeye Salmon Transportation

In early July, due to dangerous temperatures in the lower Snake River reservoirs, the IDFG began an emergency rescue effort for Snake River sockeye by capturing adults at Lower Granite Dam and trucking them to the Eagle Fish Hatchery near Boise, ID. Trucking salmon to a hatchery can be an effective immediate stop-gap measure to conserve sockeye salmon’s genetic information and prevent the extinction of this species, but it is not a viable long-term solution. IDFG staff will continue to truck Snake River sockeye salmon from Lower Granite Dam throughout July.

Breaching the lower Snake River dams will restore colder water to help migrating juvenile and adult salmon and dramatically improve their survival

IDFG undertook similar emergency salmon trucking efforts in 2015 and 2021 when weather and river conditions also turned deadly for migrating salmon. In the summer of 2015, at least 96 percent of returning Snake River sockeye salmon run died in the lower river because the reservoirs, coupled with record air temperature and low flows, elevated water temperatures to deadly levels. Snake River sockeye are among the most endangered in the Columbia Basin today. The effects of the federal hydro-system, in combination with the changing climate, are steadily elevating water temperatures in the lower Columbia and lower Snake rivers. Over time, these hot water episodes in summer are becoming more frequent, longer lasting, and more intense. Policymakers and Northwest dam and fish managers need to make big adjustments to the federal hydro-system and how we operate it in order to help struggling salmon and steelhead populations survive and begin to rebuild.

Scientific studies and computer models demonstrate that a free-flowing lower Snake River would have remained cool enough for salmon to migrate successfully despite the low snowpack and hot ambient temperatures that occurred in 2015.

Columbia Riverkeeper published a report: Computer modeling shows that Lower Snake River dams caused dangerously hot water for salmon in 2015—evaluating what the water temperatures of the lower Snake would have been during the summer of 2015 if its four federal dams did not exist. Through computer modeling, Columbia Riverkeeper found that each of the four reservoirs behind the dams increased the river temperature by about 2°F - 4°F (figure 1). The reservoirs create large, stagnant pools that steadily absorb heat from the sun. When warm water from one reservoir moves downstream to the next pool, the already-warmed water is stopped again by the next dam and continues to heat up. The model indicates clearly that this effect would be absent from the free-flowing lower Snake River.

Since Columbia Riverkeeper published its study in 2017, federal science agencies, U.S. Army Corps of Engineers¹ and EPA, released more information corroborating its findings. EPA released a study showing that, in warm years, water flowing into the lower Snake River is cool enough for fish, but water flowing out of the lower Snake River is too hot, and the dams are the main cause of this heat pollution.²

Cool water from Dworshak reservoir provides relief to migrating salmon

A free-flowing lower Snake River would not absorb the same amount of solar radiation and the resulting considerably cooler waters would deliver big survival benefits to migrating juvenile and adult salmon and steelhead populations. A free-flowing lower Snake River would also greatly expand the benefit of cold water released from Dworshak reservoir upstream on the Clearwater River in the hot summer months.

Dworshak Dam was completed in 1973. Its large reservoir is managed in summer months to release its very cold waters into the Clearwater River, just upstream from its confluence with the Snake River at Lewiston, Idaho. This week, for example, Dworshak reservoir average water temperatures are very cool, ranging between 42°F - 43°F. Dworshak’s cold water releases help keep the Lower Granite Dam reservoir (on the lower Snake River) cooler than it would otherwise be. However, as long as the four lower Snake River dams remain in place, the benefits of Dworshak’s cold flows into the lower Snake River are highly limited and serve only as a local, short-term solution to cooling water temperatures in this one reservoir. There are no detectable water temperature benefits to help struggling fish populations in the three downstream reservoirs.

By restoring this 140-mile stretch of the lower Snake River, models show that, while temperatures in a freely flowing river may spike above 68 degrees periodically, they will quickly return to the cool temperatures that salmon and steelhead need to survive and migrate. With a freely-flowing lower Snake River, cold water released from Dworshak Dam during the summer months would further help keep temperatures cool and healthy for fish from Lewiston (ID) downstream to where the Snake River joins the Columbia River in south-central Washington State near the Tri-Cities.

A restored lower Snake River would provide the largest availability of high-quality free-flowing, cold-water habitat for salmon populations to recover to significant levels of abundance, help salmon reach their spawning grounds. The benefits of dam removal would improve the ability of migrating fishes to access high-elevation, groundwater- and snowmelt-fed freshwater refuges, increasing survival and productivity in what will be increasingly challenging climate conditions.

References:
1. U.S. Army Corps of Engineers, Final Environmental Impact Statement for Columbia River System Operations, Appendix D, p. A-1-28 (2020).
2. EPA, Columbia and Lower Snake River Temperature TMDL, pp. 47–50 (2020).

The Hot Water Report is a joint project of the Save Our wild Salmon Coalition, Association of Northwest Steelheaders, Columbia Riverkeeper, Earthjustice, Endangered Species Coalition, Idaho Conservation League, Idaho Rivers United, National Wildlife Federation, Natural Resources Defense Council, Northwest Sportfishing Industry Association, Orca Network, Sierra Club, Snake River Waterkeeper, and Wild Steelhead Coalition.

View previous Hot Water Report issues at wildsalmon.org/HWR

Sockeye salmon with lesions dying from hot water in the Columbia-Snake River Basin © Conrad Gowell
Welcome to the Hot Water Report 2024: Warming Waters in the Lower Snake and Columbia Rivers.

 I. EXECUTIVE SUMMARY

• Snake River salmon and steelhead are struggling today to migrate through lethal water temperatures in the lower Snake and Columbia rivers. On all eight lower river reservoirs, temperatures continue to register above the 68°F “harm” threshold.
• On the lower Snake River, the Ice Harbor Dam reservoir registered the highest water temperature of 71.96°F on July 25. This July, the Ice Harbor Dam reservoir has reached 22 consecutive days above 68°F and 19 consecutive days above 70°F. Both Lower Monumental and Little Goose reservoirs have registered 24 days above 68°F.
• A free-flowing lower Snake River would significantly cool water temperatures and significantly reduce the slow, effortful migration through 140 miles of hot, stagnant reservoirs and fish ladders.
• In the lower Snake River, fish ladders/fish passages are the only way for fish to pass the dams. Fish ladders frequently contain water that is hotter than the average river temperature, and such conditions create or exacerbate migration blockages. By stopping or delaying migration, these blockages reduce salmon survival and reproduction.
• A free-flowing river will provide cold-water refuges that salmon and steelhead rely upon during summer migrations, improve their migration travel time, reduce stress and in-reservoir predation, and significantly increase the overall survival of endangered salmon and steelhead. 

II. INTRODUCTION

Free Flowing III 2023, acrylic and graphite on birch panel 24" x 48" x 1.5" © Britt FredaThe once-abundant anadromous fish populations in the Columbia-Snake River Basin are struggling to survive today primarily due to multiple harms caused by the federal dams and their reservoirs. The federal hydro-system creates conditions that harm and kill both juvenile and adult fish, including by elevating water temperatures in large, stagnant reservoirs in the summer months. These cold-water fish begin to suffer harmful effects when water temperatures exceed 68° Fahrenheit.

In Issue 6, we discuss how adult salmon and steelhead must migrate through eight dams and their lethally hot water reservoir and fish ladders. In the lower Snake River, fish ladders are the only route for returning adult salmon to pass the dams. Defenders of the status quo falsely claim the lower Snake River fish ladders allow salmon and steelhead to complete their migration in their historic and natural timing and without additional stress or injury to salmon. Hot water flowing in fish ladders at each dam cause salmon and steelhead to stop or substantially slow their migration, severely reducing their ability to complete their journey and spawn.

During the summer, the Hot Water Report provides real-time water temperatures in the lower Snake and Columbia river reservoirs, with updates and reports from scientists, Tribal members, fishing guides, and other experts about the challenges facing these rivers, our opportunities to recover healthy, resilient fish populations, and the benefits they deliver to Northwest communities and other fish and wildlife populations.

View the Hot Water Report issues at wildsalmon.org/HWR

III. READING THE DATA - LOWER SNAKE AND COLUMBIA RIVER TEMPERATURES

 INTRODUCTION TO THE WATER TEMPERATURE DATA:

• Throughout this summer, the Hot Water Report will provide, on a weekly basis, an update on real-time water temperatures in the lower Snake and Columbia River reservoirs.
• Data collection: The daily average and high water temperature data at the four reservoir forebays are measured with sensors stationed at various depths below the reservoir surface, immediately upstream from the dams in the lower Snake River and the lower Columbia River for 2024. The water temperatures are taken on the hour. Hourly temperatures are used to find the highest temperatures reached in each reservoir, and hourly temperature measurements are used to find the daily average temperatures.
• Average Water Temperature Graphs (below): Daily average temperatures are represented with solid lines, and the 10-year average (2014 - 2023) temperatures are with dashed lines of the same color. The dotted line across the graph represents the 68°F “harm threshold” for adult and juvenile fish.
• Weekly High Water Temperature Tables (below): This table outlines the highest water temperatures reported for each reservoir during the week and how many days water temperatures have exceeded 68°F.
• Hot water temperature effects to salmon: The longer and the higher water temperatures rise above 68°F, the greater the harm to salmon, including: migration disruption, increased metabolism, increased susceptibility to disease, reduced reproductive potential (by reducing egg viability), suffocation (warm water carries less oxygen), and in worst case - death.

IV. DISCUSSION OF DATA - LOWER SNAKE AND COLUMBIA RIVER TEMPERATURES 

LOWER SNAKE RIVER WATER TEMPERATURES: 7/25 - 7/31

Lower Snake River - 2024 Daily Average and 10-year Average.

Lower Snake River Water Temperatures - 2024 Daily Average and 10-year Average. Click on the image to view the graph and click here to view the PDF version with separate graphs for each reservoir.

• Lower Snake River Water Temperatures: this week, the Ice Harbor Dam reservoir reached a high average water temperature of 71.67°F on July 25, exceeding its 10-year average of 71°F.
• The Lower Monumental reservoir registered a high average temperature of 70.62°F and the Little Goose Dam registered 70.21°F on July 27.
• The Lower Granite reservoir registered a high average of 67.19°F. Lower Granite Dam’s reservoir’s average registered below 67°F due to the US Army Corps of Engineers’ continued cold water release effort from the reservoir behind Dworshak Dam. However, these cold water releases do not significantly cool the other three lower Snake River reservoirs.

WEEKLY HIGH TEMPERATURES IN THE LOWER SNAKE RIVER: 7/25 - 7/31

• On the lower Snake River, all four reservoirs continue to register temperatures above the 68°F “harm” threshold. This July, the Ice Harbor Dam reservoir reached 22 consecutive days above 68°F and 19 consecutive days above 70°F. The Lower Monumental and Little Goose reservoirs reached 24 days above 68°F.
• Ice Harbor Dam reservoir registered the highest water temperature of 71.96°F on July 25. The reservoir behind the Lower Monumental Dam registered the second highest water temperature of 71.26°F on July 27.
• The Little Goose Dam reservoir registered a high water temperature of 70.56°F and Lower Granite Dam reservoir reached a high water temperature of 68.52°F on July 26.

LOWER COLUMBIA RIVER WATER TEMPERATURES: 7/25 - 7/31

Lower Columbia River - 2024 Daily Average and 10-year Average.

Lower Columbia River Water Temperatures - 2024 Daily Average and 10-year Average. Click on the image to view the graph and click here to view the PDF version with separate graphs for each reservoir.

• Lower Columbia River Water Temperatures: this week, all four reservoirs on the lower Columbia River reached water temperatures above 68°F.
• The reservoir behind The Dalles Dam had a high average temperature of 70.88°F on July 27. The reservoir behind the John Day Dam reached an average temperature of 70.70°F on July 25.

WEEKLY HIGH TEMPERATURES IN THE LOWER COLUMBIA RIVER: 7/25 - 7/31

• On the lower Columbia River, The Dalles Dam reservoir registered the highest water temperature at 71.24°F on July 27. The John Day Dam reservoir reached the second highest water temperature at 70.88°F on July 25-July 26.
• The Bonneville Dam reservoir reached 26 consecutive days above 68°F and both The Dalles Dam and John Day Dam reservoirs registered above 68°F for 25 days.

Data Sources: The 2024 lower Snake River and lower Columbia River water temperature data presented in the Hot Water Report are collected from the USGS, Columbia River DART program by Columbia Basin Research, University of Washington, using data courtesy of the U.S. Army Corps of Engineers (USACE). The 10-year average water temperature data is courtesy of the Fish Passage Center. Lower Monumental 10-year average water temperatures are unavailable. Graphs and tables are assembled by SOS Staff.

V. Restoring a free-flowing lower Snake River is vital for protecting its endangered salmon and steelhead from extinction

Fish ladder at Lower Monumental Dam © Trout Unlimited

Each summer, adult salmon and steelhead struggle to migrate from the Pacific Ocean to their spawning grounds in tributaries above the lower Columbia and Snake Rivers. In this process, they encounter eight dams with fish ladders and eight hot water reservoirs. Defenders of the status quo falsely claim the lower Snake River fish ladders allow fish to complete their migration in their historical and natural timing and without additional stress or injury. Despite fish ladders at the lower Snake River dams, returning adult fish often stop or slow their migration as they encounter increasingly hot water in fish ladders and in reservoirs.

What are fish ladders?

Fish ladder and passage diagram by U.S. Army Corps of Engineers

According to the Army Corps of Engineers, as part of their salmon recovery program, fish ladders and devices to attract fish to the entrances of the ladders help fish pass the dams, “allows adult salmon and steelhead to migrate upstream of a dam on their own, provides fish time to rest as they migrate up the ladder, allows natural migration timing, and ladders are less stressful than other fish passage methods.”

Ohhh…if it were only that simple!

Hot water in fish ladders harms returning adult salmon and steelhead and interrupts their migration.

In the lower Snake River, fish ladders/fish passages are the only route past the dams. Fish ladders frequently contain water that is warmer than the average river temperature, and such conditions can create or exacerbate migration blockages, reducing salmon survival. The ladders can expose adult salmon to especially warm surface waters that are used, causing salmon and steelhead to slow or stop their migration upstream to reach the reservoir. These types of delays can reduce successful migration to spawning grounds, and increase a fish’s total thermal exposure.

Among various salmon and steelhead species, sockeye are especially sensitive to elevated water temperatures. As we reported in Issue 5, many Snake River sockeye have been observed this summer seeking refuge from hot water temperatures in the lower Snake River by moving (straying) into the Mid-Columbia River, where water temperatures are cooler.

Last summer, sockeye salmon counts at the lower Snake River dams declined when water temperatures increased. The Fish Passage Center (FPC) reported sockeye ladder counts and PIT-tag conversion in the lower Snake River dropped precipitously during the first two weeks of July. This drop in fish migrating coincided with a sharp rise in river temperature and an even larger spike in ladder temperatures at Little Goose and Lower Monumental dams. During 2023 high-temperature events, far fewer fish passed the Lower Monumental and Little Goose dams than scientists predicted. In July 2023, the highest temperatures in these fish ladders were between 68°F - 77°F. The FPC also reported that the hot water temperatures in the ladders likely contributed to the additional migration travel time for fish, which resulted in further heat stress accumulation and, therefore, a decline in adult survival and reproduction.

Throughout this month of July, Columbia Basin Research reported lower Snake River fish ladders registered high temperatures between 68°F - 78°F–significantly higher temperatures than the 68°F “harm” threshold, the legal and biological limit identified to protect salmon from lethal water temperatures.

Our options to cool the lower Snake River fish ladders are extremely limited

Fish ladder at Little Goose Dam on the lower Snake River © Tess McEnroe/Idaho Rivers United

After the catastrophic 2015 fish kill event, in which at least 96 percent of returning adult Snake River sockeye salmon died in the hot water reservoirs, the Army Corps of Engineers implemented fish cooling systems at Lower Granite and Little Goose dams in an effort to alleviate warming water. They constructed a system to pump this cool water into the Lower Granite Dam fish ladder. It is, however, totally inadequate and does nothing to cool the three downstream Snake reservoirs or meaningfully improve fish passage in those ladders.

When aging ladders and their cooling systems fail, the consequences can be dire, as there are no other options for adult salmon to pass dams and reach their spawning grounds. The water used in ladders are provided either by turbines or pumps, many of which are aging and have failed. In the event of failure, the ladders become inoperable and fish passage ceases. The Fish Passage Center reported that in 2023, fish had an especially difficult time passing the lower Monumental Dam due to high temperatures in the reservoir and fish ladders, made worse by the loss of the ladder’s cool water pump that went out of service.

A report by the Columbia River Inter-Tribal Fish Commission, states that the total cost of ladder repairs and improvements in the lower Columbia and Snake Rivers, identified by tribal, federal, and state technical experts is $160.4M today. Many billions of dollars have been spent to maintain and repair the dam infrastructure on the lower Snake River, yet, wild salmon returning to the Snake River Basin are just 0.1-2% of the abundance at the time the United States entered the 1855 Treaties with Tribes.

Restoring a free-flowing lower Snake River will provide cold clean water for salmon and steelhead and deliver big survival benefits

The lower Snake River dams, their reservoirs, and fish ladders impact fish in many ways, including elevating water temperatures, creating large, stagnant reservoirs, destroying and degrading habitat required for key life stages, and much more.

The science is clear: A free-flowing lower Snake River would no longer force fish to migrate through 140 miles of hot, stagnant reservoirs and fish ladders. A free-flowing river will provide cold-water refuges that salmon and steelhead rely upon during summer migrations, reduce their migration travel time, and significantly increase their survival.

The Hot Water Report is a joint project of the Save Our wild Salmon Coalition, Association of Northwest Steelheaders, Columbia Riverkeeper, Earthjustice, Endangered Species Coalition, Idaho Conservation League, Idaho Rivers United, National Wildlife Federation, Natural Resources Defense Council, Northwest Sportfishing Industry Association, Orca Network, Sierra Club, Snake River Waterkeeper, and Wild Steelhead Coalition.

View previous Hot Water Report issues at wildsalmon.org/HWR

Welcome to the Hot Water Report 2024: Warming Waters in the Lower Snake and Columbia Rivers.

 I. EXECUTIVE SUMMARY

• Salmon and steelhead are migrating in hot water temperatures over the 68°F “harm” threshold. As of August 4, many of the reservoirs have approached over 30 days above 68°F.
• On August 5, the Lower Granite Dam reservoir reached the highest water temperature of 72.52°F —more than 4 degrees above the 68°F “harm” threshold, the legal and biological limit identified to protect salmon.
• Climate change conditions—deeper droughts, hotter summer peaks, lower flows—all threaten the lower Snake River dams’ reliability, leading to less power when the region needs it.
• Diversifying our energy portfolio with wind, solar, and battery storage among other technologies allows us to replace the limited energy production of the lower Snake River dams and ensure we have access to affordable clean energy year-round.
• New, clean, and affordable energy sources can—and will—replace the energy provided by the four lower Snake River dams and by replacing the dams, we can provide migrating salmon and steelhead a free-flowing cold river to reach healthy and abundant levels.

II. INTRODUCTION

Monumental I: Ice Harbor 2022, oil on canvas, 48" x 48" © Rachel Teannalach

The once-abundant anadromous fish populations in the Columbia-Snake River Basin are struggling to survive today primarily due to multiple harms caused by the federal dams and their reservoirs. The federal hydro-system creates conditions that harm and kill both juvenile and adult fish, including by elevating water temperatures in large, stagnant reservoirs in the summer months. These cold-water fish begin to suffer harmful effects when water temperatures exceed 68° Fahrenheit.

In Issue 7, we will review the most common misconception that the lower Snake River dams are a reliable source of energy production during the summer and winter. However, climate change threatens to make hydropower more volatile, less abundant, and becoming less relevant to the Northwest energy landscape.

During the summer, the Hot Water Report provides real-time water temperatures in the lower Snake and Columbia river reservoirs, with updates and reports from scientists, Tribal members, fishing guides, and other experts about the challenges facing these rivers, our opportunities to recover healthy, resilient fish populations, and the benefits they deliver to Northwest communities and other fish and wildlife populations.

View the Hot Water Report issues at wildsalmon.org/HWR

III. READING THE DATA - LOWER SNAKE AND COLUMBIA RIVER TEMPERATURES

 INTRODUCTION TO THE WATER TEMPERATURE DATA:

• Throughout this summer, the Hot Water Report will provide, on a weekly basis, an update on real-time water temperatures in the lower Snake and Columbia River reservoirs.
• Data collection: The daily average and high water temperature data at the four reservoir forebays are measured with sensors stationed at various depths below the reservoir surface, immediately upstream from the dams in the lower Snake River and the lower Columbia River for 2024. The water temperatures are taken on the hour. Hourly temperatures are used to find the highest temperatures reached in each reservoir, and hourly temperature measurements are used to find the daily average temperatures.
• Average Water Temperature Graphs (below): Daily average temperatures are represented with solid lines, and the 10-year average (2014 - 2023) temperatures are with dashed lines of the same color. The dotted line across the graph represents the 68°F “harm threshold” for adult and juvenile fish.
• Weekly High Water Temperature Tables (below): This table outlines the highest water temperatures reported for each reservoir during the week and how many days water temperatures have exceeded 68°F.
• Hot water temperature effects to salmon: The longer and the higher water temperatures rise above 68°F, the greater the harm to salmon, including: migration disruption, increased metabolism, increased susceptibility to disease, reduced reproductive potential (by reducing egg viability), suffocation (warm water carries less oxygen), and in worst case - death.

IV. DISCUSSION OF DATA - LOWER SNAKE AND COLUMBIA RIVER TEMPERATURES 

LOWER SNAKE RIVER WATER TEMPERATURES: 8/1 - 8/7

Lower Snake River - 2024 Daily Average and 10-year Average.

Lower Snake River Water Temperatures - 2024 Daily Average and 10-year Average. Click on the image to view the graph and click here to view the PDF version with separate graphs for each reservoir.

• Lower Snake River Water Temperatures: this week, the Ice Harbor Dam reservoir reached a high average water temperature of 71.52°F on August 5.
• The Lower Monumental reservoir registered a high average temperature of 70.46°F and the Little Goose reservoir registered 70.95°F on August 5.
• The Lower Granite reservoir registered a high average of 70.39°Fon August 6.

WEEKLY HIGH TEMPERATURES IN THE LOWER SNAKE RIVER: 8/1 - 8/7

• On the lower Snake River, all four reservoirs continue to register temperatures above the 68°F “harm” threshold. As of August 6, many of the reservoirs have approached 30 days over the 68°F “harm” threshold. The Lower Monumental and Little Goose reservoirs reached 31 days above 68°F. The Ice Harbor Dam reservoir reached 29 consecutive days above 68°F and 26 consecutive days above 70°F.
• The Lower Granite Dam reservoir reached the highest water temperature of 72.52°F on August 5. Since August 1, the reservoir behind the Lower Granite Dam has experienced significantly high water temperatures compared to the previous week due to the temporary change of cold water releases from Dworshak Reservoir to conserve water and allow the Army Corps to complete dam power maintenance. This week, hot water temperatures in the lower Granite Dam reservoir reached between 68.09°F - 72.52°F.
• This week, the Little Goose Dam reservoir registered a high water temperature of 71.82°F, the Ice Harbor Dam reservoir registered a high water temperature of 71.73°F, and the Lower Monumental Dam reservoir registered a high water temperature of 70.83°F.