Slide background
SOS Blog

Save Our Wild Salmon


Issue 9 - August 30th, 2019

Welcome to the Hot Water Report, Week 9. This is the final report in our summer series. Over the last few months, we have looked at conditions such as water temperatures and status of salmon and steelhead returns on the lower Snake and Columbia rivers via graphs, analyses, and stories. The harmful effects on struggling fish populations caused by federal dams and their reservoirs is now being exacerbated due to our warming, changing climate.

Each week’s report has given a real-time update on water temperatures in the lower Snake and Columbia River reservoirs, the highest weekly temperature in each reservoir, and the status of adult returns for different species as they make their way back toward their natal spawning grounds. 

High sustained summer reservoir temperatures are now routine in the basin during the summer months. Salmon and steelhead begin to suffer harmful effects when water temperatures exceed 68° Fahrenheit. The longer temperatures remain above 68° and the farther the temperatures rise above 68°, the greater the harm, including increased energy expenditure, increased susceptibility to disease, reduced fecundity or reproductive potential, and/or death. 

If you are unfamiliar with the location of the lower Snake and Lower Columbia rivers and their dams, find them on this map.

Do you have feedback on this summer’s Hot Water Report series? Please send any comments to Angela Moran.

The Hot Water Report is a joint project of the Save Our wild Salmon Coalition, Idaho Rivers United, Idaho Conservation League, Sierra Club, Friends of the Clearwater, Columbia Riverkeeper, Pacific Rivers, American Rivers, and Natural Resource Defense Council.


The daily mean temperature at the forebay - the upstream side of each dam - is represented with solid lines, while the 10-year average (2009-2019) for each reservoir is represented by the dashed line of the same color. For this initial report, 10-year historic data was only available for 4 of the 8 dams we monitor. Finally, the dotted line across the top of the graph represents the upper end of the 68° “comfort zone” for juvenile and adult salmon.


Harmful water temperatures persist in the lower Snake and lower Columbia river reservoirs: The first three dams on the lower Snake have maintained the plateau that began last week, but remain well above what is considered safe for adult and juvenile salmon. The reservoir at Lower Granite, the uppermost of the four dams on the lower Snake, has been hovering just below this threshold (68°F) for the last few weeks, but this week it spiked above and joined the other three in the “not safe for salmon” zone.


Temperatures along the Columbia River have also remained relatively stable from last week. This is not necessarily good news, however, as this stable temperature is about 4° too hot for migrating salmon and steelhead.



For the first time this summer, every single reservoir had daily temperatures that peaked above the safe threshold every single day this week. As high temperatures proliferate across the river system, migrating salmon have an increasingly difficult time finding refuge and avoiding the severe consequences that accumulate as they spend extended periods of time exposed to waters that are warmer than what they have evolved to tolerate. 

Temperature data included in these reports come from the USGS Current Conditions for Washington State. Graphs and tables were assembled by SOS Staff.


As we conclude the Hot Water Report for 2019, we want to spend some time thinking about how adult salmon return data is presented and the numbers we are comparing. In previous reports, we have mainly focused on how adult salmon and steelhead returns in 2019 compare to the average return over the past ten years - the 10-year average. This is a standard analytical approach, but it has serious shortcomings. It is critical to recognize that the 10-year average presents a (downward) shifting baseline. This decadal measurement reflects steadily declining returns - but without saying so -  as the health of these populations has been plummeting over time from historic levels that were once in the hundreds of thousands and, in some cases, millions, depending on the particular population.

Therefore, this week we want to broaden our sets of data and timeframe. We’ll present estimated Snake River returns from the 1950’s - before the dams were completed. We will also look at how these numbers compare to established recovery goals* - the returns deemed necessary to recover these populations and remove these fish from the Endangered Species Act list. Since 2019 returns for Snake River populations are not quite final, we will work with adult returns from 2018. 

In all cases, we find today’s adult returns for Snake River populations dwarfed by 1950s’ figures and by estimated historic levels.




Snake River sockeye salmon - the region’s most endangered fish - they spawn in the high elevation lakes of central Idaho. 2018 returns were only about 25% of the 10-year average, but 3% of what was seen in the 1950s. Historic runs (not represented on the graph) to Idaho’s high mountain lakes used to be 100,000+ fish a year.


Snake River steelhead - wild steelhead returns in 2018 were 40% of the 10-year-average. Not good, but better than sockeye, right? Unfortunately not, as this number is just one percent of levels in the 1950s. Historic runs (not represented on the graph) of steelhead to the Snake River Basin are estimated to be approximately one million fish annually.


Spring/summer chinook - historically, these fish were Idaho’s most prolific salmon. Now, the river is experiences 50 percent returns compared to the most recent 10-year-average. . .but only 7% of 1950s/pre-dam construction numbers. Historic returns (not represented on the graph) of Snake River spring/summer chinook are estimated to have been approximately two million fish annually.



1Data courtesy of The Salmon’s Community View

2Data courtesy of The Fish Passage Center return counts to Lower Granite Dam. As wild fish are not counted, wild numbers were calculated as a proportion of the total counts, per the IDFG methods. 

Overall, we are experiencing returns of endangered fish to the Snake River that are 25-50% of the 10-year-average, but these 10-year-averages are roughly 15% of the pre-dam returns of sockeye and spring/summer chinook and just 3% for steelhead. Comparing these numbers, the concept of a ‘shifting baseline’ becomes obvious. And it’s undeniable that the status quo approach to salmon recovery is leading us steadily toward extinction. Furthermore, we are far from the the established recovery levels that are required to remove (delist) these fish from the endangered species list. Without recovery, we are on a steadfast trajectory towards complete extinction of these iconic fish - and the consequences would resonate throughout the region.

Orca.Baby.MotherOrca are starving to death and failing to reproduce. Inland and coastal fisheries are being reduced and closed. The problems are piling up and many are calling for a new approach. In a recent op-ed, Liz Hamilton of the Northwest Sportfishing Industry Association stated, “when it comes to the battle to save wild salmon, the change we need is a new vision. . .It’s time to ask as a region how we can create a future that restores abundant salmon and steelhead—and preserves our way of life for all the residents here.”

One thing is clear from this summer in the Northwest - salmon and steelhead are continuing their rapid descent toward extinction. And while salmon face multiple obstacles, water temperatures in the Snake and Columbia river reservoirs are steadily rising and creating conditions that these already-imperiled fish cannot tolerate. We need our elected officials in the Northwest to recognize the urgency of the situation before us and begin to work collaboratively with each other, with regional sovereigns and with the public to develop a regional plan that protects salmon and the benefits they bring to the region, as well as invests in the communities that depend on them.

*Note: NOAA Fisheries has never established an official recovery goal for Snake River Spring/Summer Chinook or Steelhead, but scientists estimate 80,000 wild chinook and 90,000 wild steelhead for 8 consecutive years would need to return to constitute recovery under the Endangered Species Act.


The Oregonian: We need a new vision for salmon—and the region (August 28, 2019)

CBB: With steelhead forecasted return dropping 27 percent, states extend ban on retention in lower mainstem Columbia River (August 29, 2019)

CBB: Who sets water temperature standards for Columbia/Snake Rivers? Arguments heard in ninth circuit (August 27, 2019)

The Coeur d’Alene Press: Steelhead counts lower than average in Snake River (August 22, 2019)

Previous Links:

CBB: Snake River Sockeye Run Lowest In More Than A Decade, Currently 6 Percent Of 10-Year Average (August 8, 2019)

CBB: Upriver Steelhead Forecasts Down, B-Run 24 Percent Of Average; Idaho Considers Extending Fall Chinook Fishing Areas In Clearwater (August 8, 2019)

Seattle Times: Three southern resident orcas missing, presumed dead (August 7, 2019)

The Spokesman Review: Idaho Steelhead Forecast Remains Poor (July 26, 2019)

Idaho Statesman: The first sockeye arrives at Redfish, but biologists worry few will follow. Here’s why (August 3, 2019)

Seattle Times: Three southern resident orcas missing, presumed dead (August 7, 2019)

Boise Weekly: Salmon Runs in 2019 Expected to Be Lower Than 2017, 2018 (August 7, 2019)

Columbia Basin Bulletin: River Managers Clarify Priorities On Using Dworshak’s Cool Water For Salmon Into September; Lower Granite Sockeye Passage Dismal So Far, Only 19 Fish (July 18, 2019)

Report: Revenue Stream: An economic analysis of the costs and benefits of removing the four dams on the lower Snake River (2013)

Columbia Basin Bulletin: More Salmon/Steelhead To Columbia River Than Last Year, But Forecasts Mixed Among Species (March 15, 2019)

Boise Weekly: 'The Most Complex Natural Resource Issue In The West'  Part 1 of a three-part series on Lower Snake River dam removal (April 24, 2019)

Alaska Public Media: Record warm water likely gave Kuskokwim salmon heart attacks (July 12, 2019)

CBB: Corps releases Dworshak water to cool Lower Granite tailwater for Salmon; Low sockeye run downgraded by one-third (July 11, 2019)

Idaho Statesman Editorial: Tear down these Snake River dams. A natural river saves fish and money (July 20, 1997)

Idaho Fish & Game: Very few sockeye salmon returning to Idaho (July 9, 2019)

CBB: Treaty Fishing To Begin For Summer Chinook, Sockeye; Run Forecasts Down From Last Year’s Actual Returns (June 12, 2019)

CBC: Southern resident killer whales last seen in poor health now missing (July 9, 2019)

Lewiston Morning Tribune: Spring Chinook Season Comes to a close (June 5, 2019)

Seattle Times: Chinook bust on the Columbia - Spring returns worse than forecast on Northwest’s largest river (May 30, 2019)

Seattle Times: Washington State to Regulate Federal Dams on Columbia, Snake to Cool Hot Water, Aid Salmon (January 31, 2019)

Seattle Times: Hunger, the Decline of Salmon Adds to the Struggle of Puget Sound’s Orca (February 24, 2019)

Past reports are archived here: Hot Water Reports - Compiled

Share This