INTRODUCTION:
The Hot Water Report provides real-time data in the lower Snake and Columbia river reservoirs and details the collective impacts of hot, stagnant, and toxic waters on already-imperiled salmon and steelhead. Discover how you can get involved and support comprehensive solutions to heal the river and recover healthy, abundant salmon and steelhead across the Columbia Basin.
EXECUTIVE SUMMARY:
- Current water temperatures in the lower Snake and Columbia reservoirs: On the lower Snake River, the reservoir behind the Ice Harbor Dam reached the highest water temperature of 71.64°F on August 24. The John Day Dam’s reservoir had the highest water temperature of 73.40°F on August 24. View water temperature data here.
- The Hot Water Report: Issue 3: Our energy choices today will shape the future for many generations. We can get it right. The Northwest Power and Conservation Council has released its draft 9th Power Plan and is seeking public comments. In Issue 3, we discuss the top priorities that can be improved in the final Plan to meet the region’s future energy needs and our responsibilities for fish recovery. Read more.
INTRODUCTION TO THE HOT WATER TEMPERATURE DATA:
Reading the water temperature data:
- We track water temperatures in all eight reservoirs on the lower Snake and Columbia rivers to understand the overall water conditions that salmon and steelhead must migrate through to reach their spawning grounds (adults) or the ocean (juveniles).
- 68°F Threshold: The longer and the higher water temperatures rise above 68°F, the greater the harm to the fish, including: migration disruption, increased metabolism, increased vulnerability to disease, suffocation as warm water carries less oxygen, and in the worst case - death.
- Water temperature measurements: The daily average and high water temperature data at the eight reservoirs (also known as forebays) are measured with sensors stationed at various depths below the reservoir surface, immediately upstream from the dams. See data sources here.
Click here to view the lower Snake River water temperatures - 2026 Daily Average and 10-year Average.
Snake River salmon and steelhead have to pass through eight dams and eight hot, stagnant reservoirs twice – first as juveniles and again as adults. They are using significant energy to navigate water temperatures over 69-73°F, above the 68°F threshold used to protect salmon. As water temperatures rise each day, salmon weaken, migration slows or stops, and they become vulnerable to predators, disease, parasites, and suffocation because warm water has less oxygen.
The dams and their reservoirs have changed salmon’s habitat and destroyed essential cold-water refuges that salmon and steelhead have historically relied upon to rest and recover during their migration.
Many endangered wild salmon and steelhead populations in the Columbia Basin today are less than 1-2 percent of historic levels, and 2026 adult fish returns are shaping up to be some of the lowest on record. For endangered salmon and steelhead, the main threat to their survival during their freshwater life stage is caused by the federal system of dams and reservoirs.
Recovering healthy salmon and advancing a reliable, affordable clean energy future – We can do both
Our region’s energy grid is under pressure today. There are many reasons for this, including rapidly increasing demand for electricity from proposed data centers, population growth, extreme weather events, and the need to transition away from fossil fuels.
Additional strain comes from years of drought and diminished snowpack affecting our ability to generate hydropower. Our system needs major upgrades and new renewable energy sources to meet these challenges.
Who is The Northwest Power and Conservation Council?
The Northwest Power and Conservation Council (Council) was authorized by Congress through the Northwest Power Act in 1980 to give the region a greater voice in energy planning AND protecting fish and wildlife.
The Act requires the Council to develop, with broad public participation, a Columbia River Basin Fish and Wildlife Program, and then a corresponding regional Power Plan.
What is the Northwest Power Plan? The Council produces a Northwest Power Plan every five years to forecast needs, assess supplies, and recommend a resource strategy for the future. The plan steers how the Bonneville Power Administration (BPA), utilities, and regional decision makers choose the resources needed to meet the Northwest’s electricity demand.
The Northwest Power and Conservation Council is updating its Ninth Power Plan and accepting public comment on the draft plan through October 16.
The Council’s Columbia River Basin Fish and Wildlife Program was adopted in June 2026, after a rigorous planning and public engagement process. Now, the Council needs strong encouragement to adopt a robust Power Plan that ensures we are meeting our future energy needs, AND our responsibilities for fish recovery.
Needs and Priorities to address in the Final Ninth Power Plan
The Northwest is at a crossroads—We need smart, comprehensive solutions
- Our region needs to double energy generation in the next 20 years as enormous energy demand due to data centers, high tech, and electrification are straining our system.
- Climate change (continued drought, low snowpack, El Niño) and the growing energy demand are putting unbearable pressure on imperiled fish and constraining our hydropower generation.
- Fish are in crisis – no stocks have been de-listed after 35 years, wild stocks are getting worse, and most 2026 returns are historically low.
- Fish need consistently better river conditions (more flow and spill) to stop extinction and rebuild.
- Upgrades to aging infrastructure, inflation, and costs associated with mitigating wildfire risks and extreme weather events are driving up electricity costs.
- We need new clean energy resources to address future demand, AND relieve pressure on the river and fish. Clean energy and storage resources are the most cost-effective solutions, but the region needs a substantial amount of new transmission infrastructure to add clean energy sources and meet future demands.
1. Protect and Restore Salmon and Wildlife. Changing the way the hydropower system is operated to support healthy and abundant salmon and advance a modern and reliable electricity system is a win-win for all of us.
- The Northwest Power Act requires BPA to balance hydropower benefits with fish and wildlife protection, and to do that, the Power Plan must support and explicitly advance the Columbia Basin Restoration Initiative and regional salmon recovery goals.
- Additionally, the right Power Plan resource strategy – conservation, flexibility, storage, and transmission – can replace the average 700mw produced annually from the 4 lower Snake River dams. The Council should provide technical support and modeling in partnership with Washington State Lower Snake River energy replacement planning process.
- A strong Ninth Power Plan that prioritizes conservation and a diverse portfolio of clean resources will support the Fish and Wildlife program by reducing pressure on the river and hydro generation.
- Adopt strong conservation targets and encourage regionwide collaboration to meet these goals.
- Recommend the region prioritize new clean energy and storage resources.
- Encourage BPA to continue and expand the transmission upgrade program.
- Create a Load Management Forum so that the region can maximize future flexibility and avoid further strains on the river systems.
2. Energy Conservation and Demand Response. The NW Power Act requires the Council to prioritize energy conservation. The draft plan has a great starting point for energy efficiency and demand response but the data shows there is more cost-effective potential available.
- Adopt a region wide energy conservation goal that encourages collaboration to achieve all cost-effective conservation and demand response resources.
- Recommend the region develop Model Conservation Standards for Data Centers and Heat Pump installations. These standards help clarify performance criteria, installation guides, and operational practice to help the region address these growing issues.
- Recommend BPA help regional utilities implement demand response programs and modernize energy conservation program delivery, especially to address the unique aspects of serving rural communities.
3. Clean Resources. The draft Plan clearly shows that a combination of clean supply sources—wind, solar, and storage—are the economic choice to meet new power demand. The draft Plan indicates that delays in expanding the transmission system could result in more gas generation. Instead, integrating storage and expanding transmission access will lead to more clean energy and lower costs.
- Recommend the region robustly pursue clean resources to meet future needs and remove barriers to necessary transmission connections across the four states.
- Recommend BPA prepare to acquire renewable resources and lead the region in expanding transmission capacity in order to integrate them into the grid.
- BPA's poor energy planning has left the region with overdue updates, backlog of repairs, and lack of necessary expansion to our region’s transmission system—the vital network of power lines and related infrastructure used to deliver electricity to our communities, homes, and businesses.
The Council's energy and fish recovery responsibilities are inseparable. Let's embrace this opportunity to build new energy resources to benefit fish, our water and rivers, communities, and to honor our obligations to uphold Tribal Treaties.
These measures are necessary and doable and would make meaningful progress towards salmon and steelhead recovery AND ensure a reliable, affordable energy system.
READ PAST ISSUES OF THE HOT WATER REPORT
The Hot Water Report is a project of: Save Our wild Salmon Coalition, Association of Northwest Steelheaders, Columbia Riverkeeper, Earthjustice, Idaho Conservation League, Idaho Rivers United, National Wildlife Federation, Northwest Sportfishing Industry Association, Orca Network, Pacific Rivers, Sierra Club, and Snake River Waterkeeper.
Data Sources: The 2026 water temperature data for the lower Snake River and lower Columbia River presented in the Hot Water Report are collected from the USGS, and the Columbia River DART program by Columbia Basin Research, University of Washington, with data courtesy of the U.S. Army Corps of Engineers (USACE). These data temperatures are provisional. The 10-year average water temperature data is courtesy of the Fish Passage Center and Columbia River DART program. Water temperature data is provisional. Graphs and tables are assembled by SOS Staff.
