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SOS Blog

Save Our Wild Salmon

Hot Water Report 1


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.

Water temperatures at this time 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 the Ice Harbor, the Lower Monumental, and the Little Goose reservoirs continue to exceed the ‘harm threshold’ (68 degrees) this week. On August 19th, the Ice Harbor reservoir had a high mean temperature of 72.68°F and the Lower Monumental reservoir had a high mean temperature of 71.96°F.

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 August 18th and August 19th, the John Day reservoir had the highest mean temperature of 72.32°F. The Dalles reservoir had the second highest mean temperature of 71.96°F on August 19th.

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.


On the lower Snake River, all reservoirs registered high temperatures above 68°F for multiple days. This week, the reservoir behind the Ice Harbor Dam registered the highest temperature at 73.04°F - significantly above the level that coldwater fish require. The Lower Monumental Dam had the second-highest temperature at 72.50°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 72.50°F. The Dalles Dam and the McNary Dam had the second-highest temperature at 72.32°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. Clean, non-dam alternative energy resources can benefit climate and salmon

In the Pacific Northwest (and everywhere else), we are experiencing the deadly effects of climate change.
It is, among other impacts, reducing snowpack that our region’s hydropower production depends on. With the recent IPCC report, science strongly indicates that the Pacific Northwest is expected to have more extremely hot days and diminished snowpacks, causing rivers to have lower flows and higher temperatures.1 Climate change is already creating these extreme conditions and causing reservoirs to be more dangerous for endangered and threatened salmon species each year.2,3

As global warming worsens, the lower Snake River Dams will become progressively less reliable as an energy source – especially in summer. And the shallow, slow-running river will become even warmer, further reducing salmon survival and abundance. Scientists predict that removing the four lower Snake River dams and restoring a free-flowing river can help to significantly mitigate climate impacts on salmon and steelhead and help ensure a healthy, sustainable future for endangered salmon and steelhead - and the communities that rely upon them.4

Washington is the fourth state to enact legislation to drastically reduce climate change impacts by adopting a plan and timeline for transitioning to 100 percent carbon-free electricity.5 The Washington Clean Energy Transformation Act commits Washington to aggressively transform its electricity system to carbon-neutral electricity by 2030 and 100 percent clean electricity by 2045.6 Washington State is now on a pathway to replace its non-renewable energy resources with carbon-free, renewable, affordable, and salmon-friendly alternatives.7 Removal of the lower Snake River dams and replacement of their energy services must become part of this plan.

We have an opportunity - and necessity - today to make critical changes in the Northwest to protect, restore and reconnect the freshwater habitats that salmon and steelhead depend upon. At the same time, our salmon recovery strategies must also (1) help address larger regional efforts to significantly reduce carbon emissions and transition to carbon-free, renewable and ecologically-sustainable resources; (2) address the harmful effects (altered hydrograph, hot river temperatures, 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; and (3) help support and maintain an affordable energy system for Northwest people and communities.

The Lower Snake River Dams:

The four federal dams on the lower Snake River in Washington State — Ice Harbor, Lower Monumental, Little Goose, and Lower Granite were built between 1955 and 1975. They are now in need of extensive maintenance and upgrades to the dams’ hydropower turbines, which are estimated to cost the Bonneville Power Administration (BPA) and its ratepayers over a billion dollars.8 The U.S. Army Corps of Engineers, which operates the dams, announced a $58 million project in 2016 to upgrade just two of the six turbines at Ice Harbor, indicating the significant investments required to upgrade and maintain these dams moving forward. The four dams supply just 4% of the region’s electricity.9,10 These investments would be better spent on carbon-free, renewable, and ecologically-sustainable energy alternatives.

Each year, the four lower Snake River dams produce less than 1,000 average megawatts (aMW). Most of their energy is produced in the spring during the snowmelt – a time of high supply and low price.11 In winter and late summer, when electricity is most needed and most valuable, these four dams generate less than 425-525 megawatts because there is very little water available in the river to spin turbines.11 Climate experts predict we’ll have less water available in the years ahead, which means these aging dams will produce less power while costing more to repair.

A highly dynamic energy sector today also means that the electricity these four dams produce can be easily and affordably replaced. Studies conclude that the economic benefits of salmon and steelhead recovery exceed the costs to replace the dams’ seasonally limited power.11 With renewable energy technologies expanding and evolving, we can integrate new renewable resources and invest in energy efficiency projects to replace the modest energy services the dams provide today.

Abundant, Wild Salmon AND Affordable, Carbon-Free Energy:

In the Northwest, we’re investing in energy efficiency, distributed clean renewables, energy storage, and load management programs, and making our energy grid more reliable and affordable. 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.12

Two earlier studies also found promising results: we can replace the power from the four LSR dams at little additional cost to customers through new, renewable energy, purchases of clean energy from existing sources, and smart planning and system coordination.13,14 Decades of research also show that replacing hydropower energy with renewable resources like wind and solar has little to no increase in household bills or greenhouse gas emissions. In addition, developing wind and solar replacement for the dams on the lower Snake River will provide thousands of jobs across Northwest communities.9

Cold waters required by migrating salmonids are extremely limited in the Columbia-Snake River hydrosystem today; there are no additional resources available that can significantly cool the river. Restoring the lower Snake River will significantly reduce mainstem water temperatures on a long-term basis, and is likely the only action that can do so to avoid the extinction for the Northwest’s native fish and the many benefits they bring to our region.

1.The Seattle Times: Snowpack drought has salmon dying in overheated rivers (July 25, 2015)
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. Earthjustice: Why restoration of the lower Snake River is necessary to save wild salmon (July 31, 2020)
5. Governor Inslee: Washington Enacts Strongest Clean Electricity Standard in the Nation (May 2019)
6. Governor Inslee: Energy & Environment (May 2019)
7. Save Our wild Salmon: Tackling the Climate Challenge
8. Sierra Club: Salmon near extinction. Orcas Starving.Restore the Snake River and its abundant habitat (2019)
9. American Rivers: Snake River Vision: Energy Replacement (July 7, 2021)
10. NW Energy Coalition: The Lower Snake River Dams Power Replacement Study (April, 2018)
11. Save Our wild Salmon: Why Remove The 4 Lower Snake River Dams? (2018)
12. NW Energy Coalition: The Lower Snake River Dams Power Replacement Study Fact Sheet (April, 2018)
13. NW Energy Coalition: Restoring Wild Salmon – Power costs and benefits of lower Snake River dam removal (August 2015)
14. Rocky Mountain Econometrics: Lower Snake River Dams Alternative Power Costs (June 22, 2015)

Photo Credit:
1. Technicians install rooftop solar panels in Spokane, Washington, in September 2016: Photo by Chris Jordan-Bloch/Earthjustice
2. Wind Turbines in Wheat Field: Photo by Daniel Parks/American Rivers


 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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