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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 have exceeded the threshold (68 degrees) this week. They have consistently maintained mean temperatures above 70°F. On August 14th, the Lower Monumental reservoir had a high mean temperature of 71.96°F. The Ice Harbor reservoir had a high mean temperature of 71.78°F on August 15th to August 17th.

This week, the release of cold water from the Dworshak reservoir upstream in the Clearwater drainage is cooling the Lower Granite reservoir. However, the benefits of Dworshak’s cold flows are limited and serve only as a short-term solution to cooling water temperatures in the Lower Granite Dam’s reservoir. 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 71°F. On August 14th and August 15th, the Bonneville reservoir had the highest mean temperature of 73.94°F. The John Day reservoir had the second highest mean temperature of 73.76°F on August 13th.

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 Lower Monumental Dam registered the highest temperature at 73.04°F - significantly above the level that coldwater fish require. The Ice Harbor Dam had the second highest temperature at 72.14°F

On the lower Columbia River, all reservoirs registered high temperatures above 71°F for multiple days. The reservoir behind the John Day Dam had the highest temperature this week at 75.02°F. The Bonneville Dam had the second highest temperature at 74.30°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. Intergovernmental Panel on Climate Change Report:

Save Our wild Salmon is committed to working with others in the Pacific Northwest to craft solutions that both protect and restore healthy, self-sustaining, harvestable populations of salmon and steelhead and help tackle the challenges we face from a warming climate. This integrated work to protect both salmon and climate is essential given our coalition’s focus on recovery in the Columbia-Snake River Basin and the predominant role the federal hydro-system plays to endanger these iconic fish and this ecosystem. The effects of climate change are worsening the already-lethal impacts of the dams and their reservoirs by further disrupting the rivers’ natural flows (hydrograph), raising river/water temperatures, increasing native and non-native populations of predatory fish like bass and pikeminnow, and more.

This week, we will focus on the latest Intergovernmental Panel on Climate Change (IPCC) Report and how this report will inform us on climate change-related consequences for the Pacific Northwest and its fish and wildlife and communities.

About the IPCC: The Intergovernmental Panel on Climate Change (IPCC) is the “international body for assessing the science related to climate change. The IPCC was set up in 1988 by the World Meteorological Organization (WMO) and United Nations Environment Programme (UNEP) to provide policymakers with regular assessments of the scientific basis of climate change, its impacts, and future risks and options for adaptation and mitigation.”1The IPCC released the first installment of the IPCC’s Sixth Assessment Report (AR6), Climate Change 2021: The Physical Science Basis, which will be completed in 2022.1

Findings of the IPCC Report:  The U.N. Secretary General António Guterres calls the findings in the IPCC report “a code red for humanity.”2 The report states that greenhouse gas emissions have warmed the climate at a rate that is unprecedented in at least the last 2,000 years.2 Greenhouse gas emissions from “human activities are responsible for approximately 1.1°C of warming since 1850-1900”, and “global surface temperatures were 1.09°C higher in 2011-2020 than in 1850-1900.”1,3 The report states that on “average over the next 20 years, global temperature is expected to reach or exceed 1.5°C of warming (2.7°F increase in average global temperatures).”1

“Global surface temperature will continue to increase until at least the mid-century under all emissions scenarios considered. Global warming of 1.5°C and 2°C will be exceeded during the 21st century unless deep reductions in carbon dioxide (CO2) and other greenhouse gas emissions occur in the coming decades.”4 Furthermore, with a deep reduction in emissions of carbon dioxide (CO2) and other greenhouse gases would limit climate change and it would take 20-30 years to see global temperatures stabilize.1

The IPCC report developed an interactive atlas that shows global temperature rise across different countries. The temperatures include +1.5°C, +2°C, +3°C, and +4°C above pre-industrial levels and all scenarios point that climate changes will increase in all regions around the globe.5 The report states that for the 1.5°C of global warming scenario, there will be an increase in heat waves, longer warm seasons, and shorter cold seasons.1 However, limiting warming at 1.5°C above pre-industrial levels is the best-case scenario as it would mean rapidly cutting fossil fuel emission to “net-zero” by the year 2050 and would eventually stop glaciers from melting and sea-level rise to slowly decrease.6

In the ‘2°C global warming scenario’ (3.6°F increase in average global temperatures), heat extremes are projected to be 14 times more likely to occur and would significantly impact agriculture and communities’ health.1,7 Since air can hold more moisture at 2°C global warming, more droughts, and extreme rainfall occur more frequently.1 Finally, in the 4°C global warming scenario (7.2°F increase in average global temperatures), the report states that intense heat waves that used to occur about once every 50 years will become annual events.1

Warming beyond 2 degrees Celsius carries an increased risk of setting off feedback processes that cause climate change to accelerate and bring profound disruptions to different regions, for example:

  • “Climate change is intensifying the water cycle. This brings more intense rainfall and associated flooding, and more intense drought in many regions.
  • Coastal areas will see continued sea-level rise throughout the 21st century, contributing to more frequent and severe coastal flooding in low-lying areas and coastal erosion. Extreme sea-level events that previously occurred once in 100 years could happen every year by the end of this century.
  • Further warming will amplify permafrost thawing, and the loss of seasonal snow cover, melting of glaciers and ice sheets, and loss of summer Arctic sea ice.
  • Changes to the ocean, including warming, more frequent marine heatwaves, ocean acidification, and reduced oxygen levels have been clearly linked to human influence. These changes affect both ocean ecosystems and the people that rely on them, and they will continue throughout at least the rest of this century.
  • For cities, some aspects of climate change may be amplified, including heat (since urban areas are usually warmer than their surroundings), flooding from heavy precipitation events, and sea-level rise in coastal cities.”1

Possible Climate Futures for the Pacific Northwest: In the Pacific Northwest, ecosystems and biodiversity will suffer from increased wildfires, drought, floods, shrinking glaciers, and low snowpacks, and the spread of invasive species, pests, and disease.8 If greenhouse gas emissions continue on their current pathway, the Pacific Northwest is expected to have extremely hot days and frequent extreme weather events that would also reduce air quality.8

We are currently experiencing extreme weather events such as heatwaves and wildfires in Washington, Oregon, and Idaho. Scientists predict the impacts of 2015’s extreme weather events are foreshadowing our future. During 2015, Northwest average temperatures were about 2.7°C warmer than pre-industrial (1.9°C, above the 1970-1999 average), and Washington state snowpack was 70% normal (1970-1999 average).8 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.11,12

If greenhouse gases continue to rise, we can expect snowpacks to further decline, causing rivers to have lower flows and higher temperatures.10 Climate change will exacerbate these extreme conditions and cause reservoirs to become more dangerous for endangered and threatened salmon species each year.11,12

Healthy Climate and Resilient Habitats are Still Possible:  The IPCC clearly states that the main drivers of climate change are greenhouse gases such as carbon dioxide (CO2), and we have the potential to determine the future course of climate.1 IPCC Working Group 1 Co-Chair Panmao Zhai states, “Stabilizing the climate will require strong, rapid, and sustained reductions in greenhouse gas emissions, and reaching net-zero CO2 emissions. Limiting other greenhouse gases and air pollutants, especially methane, could have benefits both for health and the climate.”1

The World Meteorological Organization (WMO) Chief, Petteri Taalass, also states, “The message of the IPCC report is crystal clear: we have to raise the ambition level of mitigation.9

For the Pacific Northwest salmon and steelhead, this means, among many other actions, removing the four harmful dams on the lower Snake River to restore a free flowing, more natural and resilient river. Restoring the Snake is an essential mitigation measure to re-create more natural river conditions that these fish need to survive and thrive.13

Fortunately, our region today is equipped to replace non-renewable energy sources and the lower Snake River hydropower dams with carbon-free, clean, renewable, affordable, and salmon-friendly alternatives.13
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.

1. Intergovernmental Panel on Climate Change: Climate change widespread, rapid, and intensifying – IPCC (August 9, 2021)
2. The Washington Post: Five key excerpts from the United Nations’ climate change report (August 10, 2021)
3. Intergovernmental Panel on Climate Change: Climate Change 2021, The Physical Science Basis: Summary for Policymakers (August 7, 2021)
4. Intergovernmental Panel on Climate Change: Headline Statement from the Summary for Policymakers (August 9, 2021)
5. Intergovernmental Panel on Climate Change: WGI Interactive Atlas
6. The Washington Post: Humans have pushed the climate into ‘unprecedented’ territory, landmark U.N. report finds (August 10, 2021)
7. The Seattle Times: Shrinking glaciers, extreme heat waves, worsening droughts: What the landmark climate report means for Western U.S., Seattle (August 9, 2021)
8. Snover, A.K, C.L. Raymond H.A. Roop, H. Morgan, 2019. “No Time to Waste. The Intergovernmental Panel on Climate Change’s Special Report on Global Warming of 1.5°C and Implications for Washington State.” Briefing paper prepared by the Climate Impacts Group, University of Washington, Seattle
9. United Nations: IPCC report: ‘Code red’ for human driven global heating, warns UN Chief (August 9, 2021)
10. The Seattle Times: Snowpack drought has salmon dying in overheated rivers (July 25, 2015)
11. 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).
12. 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.
13. Save Our wild Salmon: Tackling the Climate Challenge


 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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