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'Hot Water Pollution' Lawsuit Threat Aims to
Remove 4 Eastern WA Dams to Save Salmon

by Annette Cary
Tri-City Herald, July 24, 2023

This Sockeye adult is the first to return of 2015 to Idaho's Redfish Lake near Stanley, Idaho Four conservation and fishing groups plan a lawsuit over high water temperatures in the Snake River, calling for actions that could include removing the four lower Snake River dams in Eastern Washington.

Columbia Riverkeeper, Idaho Rivers United, Idaho Conservation League and the Northwest Sportfishing Industry Association formally notified the Army Corps of Engineers on Friday that it could file the lawsuit in 60 days.

Hot water in the lower Snake River is killing and injuring sockeye salmon, which are at high risk of extinction, said the notice to the Corps.

It said the four lower Snake River hydroelectric dams from Ice Harbor Dam near the Tri-Cities upriver to Lower Granite Dam near Lewiston, Idaho, are primarily responsible for the high water temperatures.

Without the four dams, the lower Snake River would remain cool enough to allow most sockeye salmon to migrate safely, even in very hot years, the legal notice said.

"Hot water in the lower Snake River has been a year-in, year-out problem for endangered salmon," said Nic Nelson, executive director of Idaho Rivers United.

"Despite above-average snowpacks and a colder spring, we still have significant hot water pollution threatening these endangered fish," he said. "The only way to save these runs are substantive changes to the system of operations on the Columbia-Snake River systems."

River water that is too warm encourages the growth of disease-causing bacteria and fungi, delays migration and depletes the energy reserves of migrating fish, according to a Columbia Riverkeeper report on the dams and water temperatures, particularly in the hot summer of 2015.

Adult salmon have difficulty migrating upstream when water temperatures approach 68 degrees, and they stop heading upstream when water temperatures reach 72 to 73 degrees, the report said.

The lower Snake River water in the summer of 2015 was hotter than 68 degrees for two months. The Environmental Protection Agency concluded that roughly 250,000 adult sockeye salmon returning to the Snake or to upper Columbia tributaries died because of warm water, the report said.

The legal notice to the Corps put the 2015 adult Snake River survival rates at 4%, by far the worst in the decade.

Last year the estimated survival rate was 66%, which met the survival rate of 65% that year as mandated under the Endangered Species Act, according to information in the legal notice to the Corps.

"It's ironic that anti-dam groups are announcing this lawsuit in the name of sockeye salmon when this year has had one of the best sockeye returns to the Snake River in recent memory," said Kurt Miller, executive director of Northwest RiverPartners, which represents Northwest electric utilities, plus river transportation and agriculture interests.

Hot air temperatures cause hot river temperatures and heat-related salmon die-offs are being seen in the undammed Fraser River in Canada and rivers as far north as Alaska, Miller said.

Removing the hydroelectric dams will make climate change worse and river temperatures more dangerous to salmon, he said.

He also pointed out that a 2020 study by the National Oceanic and Atmospheric Administration said the undammed Salmon River was more at risk for extreme river temperatures than the lower Snake River.

The Corps has long said that the courts lack the authority to order Snake River dam removal.

But the groups planning the lawsuit based on the Endangered Species Act argue that the U.S. Supreme Court has said that congressional authorizations for federal dams do not create exemptions to the act and cannot prevent them from being prohibited.

They told the Corps that unless the Biden administration took action on a solution to save salmon in the Columbia River and its tributaries as he pledged in March, it would file the lawsuit as soon as Sept. 18.

Related Pages:
Washington State Board Plans to Enforce Temperature Limits on Snake and Columbia Rivers by Lynda V. Mapes, Seattle Times, 6/30/21 Report: Washington Salmon are in Hot Water by Aaron Kunkler, Snoqualmie Valley Record, 2/1/21
Research: Sockeye are in Hot Water by Eric Barker, Lewiston Tribune, 10/2/20
Salmon Struggle to Beat Heat in Columbia River Basin by Eric Tegethoff, Washington News Service, 9/10/20
Scientists Assert Only Breaching Can Cool Northwest Waterways by Eric Barker Post Register, 10/23/19
Riverkeeper: No Sustained Hot Water Temps if Lower Snake Dams Go by Laura Berg, NW Fishletter, 9/5/17
Rising River Temperatures Put Endangered Salmon in Hot Water by Kevin Taylor, Aljazeera America, 8/25/15

Snake River sockeye and Chinook salmon in a changing climate:
Implications for upstream migration survival during recent extreme and future climates


In 2015, the Pacific marine heat wave, low river flows, and record high water temperatures in the Columbia River Basin contributed to a near-complete failure of the adult migration of endangered Snake River sockeye salmon (Oncorhynchus nerka, NOAA Fisheries 2016). These extreme weather events may become the new normal due to anthropogenic climate change, with catastrophic consequences for endangered species. Existing anthropogenic pressures may amplify vulnerability to climate change, but these potential synergies have rarely been quantified. We examined factors affecting survival of endangered sockeye (Oncorhynchus nerka) and threatened Chinook salmon (O. tshawytscha) as they migrated upstream through eight dams and reservoirs to spawning areas in the Snake River Basin. Our extensive database included histories of 17,279 individual fish that migrated since 2004. A comparison between conditions in 2015 and daily temperatures and flows in a regulated basin forced by output from global climate models showed that 2015 did have many characteristics of projected future mean conditions. To evaluate potential salmon responses, we modeled migration timing and apparent survival under historical and future climate scenarios (2040s). For Chinook salmon, adult survival from the first dam encountered to spawning grounds dropped by 4-15%, depending on the climate scenario. For sockeye, survival dropped by ~80% from their already low levels. Through sensitivity analyses, we observed that the adult sockeye migration would need to shift more than 2 weeks earlier than predicted to maintain survival rates typical of those seen during 2008-2017. Overall, the greater impacts of climate change on adult sockeye compared with adult Chinook salmon reflected differences in life history and environmental sensitivities, which were compounded for sockeye by larger effect sizes from other anthropogenic factors. Compared with Chinook, sockeye was more negatively affected by a history of juvenile transportation and by similar temperatures and flows. The largest changes in temperature and flow were projected to be upstream from the hydrosystem, where direct mitigation through hydrosystem management is not an option. Unfortunately, Snake River sockeye have likely lost much of their adaptive capacity with the loss of the wild population. Further work exploring habitat restoration or additional mitigation actions is urgently needed.

Annette Cary
'Hot Water Pollution' Lawsuit Threat Aims to Remove 4 Eastern WA Dams to Save Salmon
Tri-City Herald, July 24, 2023

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