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SOS Blog

Save Our Wild Salmon

Hot Water Report 1


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 water episodes 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 RiverkeeperAmerican 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.


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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.

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)


 Martha Bio picMartha 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.


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