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°F on 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.

LOWER COLUMBIA RIVER WATER TEMPERATURES: 8/1 - 8/7

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 reached water temperatures above 68°F.
• The reservoir behind the Bonneville Dam had a high average temperature of 71.78°F on August 3. The reservoir behind The Dalles Dam reached an average temperature of 71.42°F on August 2.

WEEKLY HIGH TEMPERATURES IN THE LOWER COLUMBIA RIVER: 8/1 - 8/7

• On the lower Columbia River, the Bonneville Dam reservoir registered the highest water temperature at 72.14°F on August 2. The Dalles Dam reservoir reached the second highest water temperature at 71.96°F on August 2.
• The Bonneville Dam reservoir reached 33 consecutive days above 68°F and both The Dalles Dam and John Day Dam reservoirs registered above 68°F for 32 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. Lower Snake River dams’ energy reliability in the face of climate change

Monumental II: Lower Monumental 2022, oil on canvas, 48" x 48" © Rachel Teannalach

On the lower Snake River, we are currently experiencing over 30 days above the 68°F “harm” threshold, with many of the reservoirs reaching water temperatures between 70°F - 72°F. The lower Snake River dams and their reservoirs are creating hot waters that are lethal to salmon and steelhead, leading to a significant decline in their survival. Since the construction of the four lower Snake River dams over 60 years ago, Snake River salmon and steelhead populations have been steadily declining toward extinction. The warming waters, exacerbated by rising temperatures and reductions in snowpack due to climate change, are worsening the conditions for these fish.

Defenders of the status quo often depict the lower Snake River dams as 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.

How does climate change impact the lower Snake River dams’ energy reliability?

The energy production from the lower Snake River dams (LSRDs) are increasingly variable and annual power production varies unpredictably from year-to-year due to climate change-impacted water conditions and fluctuating seasonal energy generation.

Climate changes affect air temperatures, precipitation, snowpack, and wind patterns in the Pacific Northwest, it brings an increase in land and river heat waves, droughts, and variations in river flow patterns. The increased drought and reduced snowpack constrain the power and capacity functions of the dams.

The dams have a combined “nameplate” capacity of 3443 megawatts, but they do not actually produce remotely that much power. In a year with high water flows, the dams will produce 1136 average megawatts (to give a sense of scale, Seattle City Light supplies customers in the city and some suburbs with 1063 average megawatts). But, in a low water year, the lower Snake dams will generate only 583 average megawatts – about half as much (51.3%) as in a wet year with lots of snow. The median annual generation of the lower Snake dams is just 782 average megawatts.

Then there’s seasonal variability. Water in the rivers does not flow in the same volume throughout the year, so neither does energy production. All over the Northwest and, indeed, the whole West, hydropower production peaks in late spring and early summer, as winter snows melt and rivers rise. Over the ten years from 2014 through 2023, the LSRD produced an output of 1428 average megawatts in May, but just 404 average megawatts in August. Most of the power generation from the LSRDs occurs when the rest of our energy resources are also producing significant output.

The above figures are from the Bonneville Power Administration’s 2024 “White Book”, their annual summary of loads and resources. They are based on records from the previous thirty years of stream flows. But with climate change, the future will not be like the past. In fact, Bonneville has acknowledged that. Until 2022, they based their estimate of hydropower resources on a ninety-year stream flow record. Recognizing that what happened in the 1930s was increasingly irrelevant to today’s conditions, the agency switched to the thirty-year record.

As Bonneville explained, “…over the last several decades increasing temperatures throughout the Columbia River Basin …have contributed to increased average winter and early spring flows, with average peak spring runoff now appearing several days earlier, along with decreased summer flows. The best available climate change science… indicates that in the coming decade, these trends will likely continue. Temperatures in the Columbia River Basin are expected to continue to increase. The region is also expected to experience wetter winters, longer summer dry periods, declining snowpack, higher average fall and winter flows, earlier peak spring runoff, and longer periods of low summer flows.”

But, of course, the next thirty years are not going to be like the previous thirty either. The most recent events are most relevant. 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. The New York Times recently reported, “In the United States, hydropower generation fell 6 percent last year. The decline was mostly attributed to high temperatures having melted snow too quickly in the Northwest, leading to huge water loss that curbed energy production in hydropower plants.”

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.

Lower Snake River dams during summer and winter energy demands

In a report, Addressing the Lower Snake River Dams’ Peaking Capacity, the NW Energy Coalition, outlines the limitation of the lower Snake River dams as climate change worsens and its several emblematic consequences the Northwest is heading by keeping the dams in place.

Summer peaking demand in the Northwest often occurs as a heat wave forces residents to turn up air conditioning, most commonly in late summer. Figure 1 shows that late summer has the lowest generation, due to little precipitation and low river flows. Climate change will only exacerbate late summer’s low generation as drought reduces precipitation and river flow. However, late summer is also forecasted to have increasing energy demand in our region, as climate change drives longer and more frequent heat waves across the region. With the effects of climate change, we can expect LSR dam energy generation to become less valuable.

Winter peaking demand in the Northwest most commonly occurs when residents turn up their heating systems. Winter cold snaps in the Northwest are likely to occur in December or January. In Figure 1, the generation profile exceeds the peaking capacity of 132,500 MWh only during February through June, a time period when winter cold snaps are less likely, grid demand is lower in the spring as the winter heating season ends, and there is already an abundance of power on the grid due to spring runoff. December and January are periods of low generation for the LSR dams due to low river flow as precipitation falls as snow. As climate change worsens, this trend may change as more precipitation in winter falls as rain rather than snow. However, climate change also causes more interannual variation, further complicating the ability to forecast future winter sustained peaking capacity.

A pathway to clean reliable energy without the lower Snake River dams

Snake River © Steve Ringman/The Seattle Times

Unprecedented summer heat and deep cold snaps show the urgent need to diversify energy resources to improve reliability during the winter and late-summer demand peaks. As climate change worsens, the dams will only become more unreliable, especially during summer and winter demands, and will remain costly to maintain and operate the four dams.

The Biden-Harris Administration in an historic agreement announced their partnership with Pacific Northwest Tribes and States to restore wild salmon populations, expand Tribally sponsored clean energy production, and provide stability for communities that depend on the Columbia River System. With this step forward from the Administration, it is even more crucial that we mobilize the affordable and clean energy sources we already have at our disposal. Diversifying our energy portfolio with wind, solar, and battery storage among other technologies allows us to not only replace the limited amount of energy produced by the lower Snake River dams, but it also ensures we have access to clean energy when we actually need it – not when we already have a surplus. Prioritizing a diverse portfolio of clean energy sources is the best way to create a sustainable and resilient energy grid as climate conditions become more variable.

New, clean, and affordable energy sources can—and will—replace the energy provided by the four lower Snake River dams. By removing the four dams and restoring a free flowing lower Snake River, we can 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.

VI. In the Media - High Country News: Nez Perce energy transition to save salmon

Nimiipuu Energy © Mezia Creative Media

Just past the [Nez Perce] reservation’s border, a billboard greets the driver with an admonition, urging you to “Honor the Treaty of 1855 with the Nez Perce — Breach the Snake River Dams.”

The billboard is the tribe’s response to the four hydropower dams on the Snake River. The Lower Snake River dams have long been controversial for the part they have played in decimating the Pacific Northwest’s once-abundant salmon and steelhead populations.

As night falls on the reservation, another response can be seen in the growing number of homes illuminated by solar power. In an innovative push to replace the hydroelectricity generated by the four dams, the Nez Perce Tribe is creating a new energy infrastructure that could make it easier to breach the dams and restore the salmon.

SOLAR PANELS SHINE from rooftops across the Nez Perce Reservation thanks to the tribe’s solar initiative, Project 5311. Launched in 2022 under the tribal company Nimiipuu Energy, it is named for the amount of solar power the Snake River dams’ operator says is required to replace the electricity the dams generate: 5,311 megawatts. The tribe’s goal is to eventually produce 5,311 megawatts of energy, beginning by generating 500 megawatts by 2027. It is catalyzing a clean energy transition that could help loosen hydropower’s grip on the Pacific Northwest.

“This is an opportunity to create energy,” said Shannon Wheeler, chairman of the Nez Perce Tribe. “Project 5311 is something of a vision that can be utilized for the development of other energy projects that will definitely come together at some point in time.” 

Most recently, on Feb. 23, the Biden administration joined four tribal nations and the states of Oregon and Washington to sign the Columbia River Basin Agreement in support of the development of alternative energy in the Pacific Northwest as part of a path toward breaching all four dams.

“The Biden administration agrees that we need to do something different to recover salmon populations in the Columbia Basin,” said Kayeloni Scott, a member of the Spokane and Nez Perce Tribes and communications consultant for the Nez Perce. “The status quo is not working. It’s not green energy if it’s killing fish.”

Both Scott and Wheeler believe that Project 5311 is on track to meet its goal by 2027. The working mantra for some of the workers and panel installers is that each solar panel represents one fish. In offering solar for salmon, the Nez Perce Tribe hopes to energize a transition that helps the people uphold the deep cultural relationship they have with the fish.

“To see the salmon return would restore peace in my heart,” Wheeler said. “Fishing with my relatives reminds me of times in my life when I was safe and at peace. That is what the salmon covenant means to me.”

Read the full article here

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