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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 begin to 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 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 all four reservoirs have exceeded the threshold (68 degrees) all week. The Ice Harbor Dam and Little Goose Dam reservoirs have consistently maintained mean temperatures above 68°F, and with a high mean temperature of 71.78°F. The Lower Granite Dam had a high mean temperature of 71.24°F on August 4.

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 5, 2021, the John Day reservoir had the highest mean temperature of 73.58°F. The Dalles reservoir had the second highest mean temperature of 73.04°F. 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 69°F for multiple days. This week, the reservoir behind Ice Harbor Dam registered the highest temperature at 72.32°F - significantly above the level that coldwater fish require. The Little Goose 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 74.30°F. The Dalles Dam had the second-highest temperature at 73.40°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.


Over the past 30+ years, scientific studies have conclusively found that removing dams and restoring freely-flowing rivers helps protect and rebuild healthy, abundant salmon and steelhead populations. This is certainly true in the Klamath River Basin that straddles the California-Oregon border. Like the Snake, the Klamath provides a compelling example of the critical need for dam removal to address high water temperatures and other harmful effects caused by the dams and their reservoirs. One of the most effective actions that we can take to mitigate the harms to rivers caused by the warming climate - including high water temperatures - is to restore and reconnect the rivers.

(Image from California Fish Passage Forum: Preparing the Klamath Basin for Dam Removal)

Since time immemorial, the Klamath River Basin has been home to Indigenous People including the Yurok, Karuk, Hoopa, Shasta, and Klamath Tribes.1 The Klamath River has over 45 native species, including Chinook and Coho salmon, steelhead and coastal cutthroat trout, suckers, green and white sturgeon, and Pacific lamprey.1 Klamath River salmon runs were once the third-largest in the nation but have fallen to just eight percent of their historic numbers.1

For nearly 100 years, the hydroelectric dams on the Klamath River have “contributed to devastating declines in water quality, the region’s anadromous fisheries, and the tribal, recreational, and commercial economies and communities they support.”2 The four dams – J.C. Boyle, Copco No. 1, Copco No. 2, and Iron Gate continue to block salmon and steelhead from reaching 420 miles of habitat and have harmed water quality for people and wildlife.3 As a result, the Coho salmon are federally listed as threatened under the Endangered Species Act.4 In addition, the Upper Klamath-Trinity River Spring Chinook salmon are listed under California’s Endangered Species Act as of 2021.4

In September 2002, the Klamath River had the largest salmon kill in the American West, as an estimated 34,000-70,000 chinook, coho, and steelhead died.1 The cause of the fish kill was a unique combination of factors including low flow rates and volume from Iron Gate Dam that caused migration delays, crowded conditions, and high water temperature that supported an outbreak of parasites and bacterial pathogens that harmed salmon.5 As a result, between 2002 - 2008, the Klamath River salmon runs dropped significantly, and have yet to recover.6 Since 2015, California has seen a continuing decline in Klamath salmon populations, and with record-low return rates, many Northern California Klamath-dependent ocean commercial salmon fisheries have closed.6

With strong tribal leadership from Yurok, Karuk, Hoopa, and Klamath Tribes in Oregon and California, more than 40 sovereigns and stakeholders (irrigators, fishing interests, etc) developed an initial agreement to remove the dams, restore habitat, and resolve decades-long water management disputes.1 Dam removal is essential as the four dams do not provide flood control and irrigation and only generate a small amount of hydropower, which can be affordably replaced using renewables and efficiency measures.1 In 2010 and 2011, the Public Utilities Commissions in Oregon and California concluded that removing the dams (instead of spending more than $500 million to bring the dams up to modern standards) would save PacifiCorp (now a subsidiary of Warren Buffett’s Berkshire Hathaway) customers more than $200 million.

Fast-forward to November 2020 when the Karuk and Yurok Tribes, California Governor Newson, Oregon Governor Brown, Klamath River Renewal Corporation, and PacifiCorp announced their unified support and plan for removing the four large dams that have destroyed many miles of once-highly productive salmon habitat in the Klamath River Basin.7 Initially, the Klamath River dams were scheduled to be removed in 2020, but inaction by Congress and the federal government delayed the dam removal process.4 Finally, after a decades-long campaign, removing the four dams and restoring the Klamath River and its endangered salmon is scheduled to begin in 2023. By removing the 173 foot tall Iron Gate dam, the 126 and 20 foot tall Copco dams, and the 60 foot tall J.C. Boyle dam in the Klamath River, it will restore access to more than 420 miles of ancestral habitat for anadromous species, which is noted to be the most significant and largest dam removal project in the world to date.3

Recently, the Federal Energy Regulatory Commission (FERC) approved the transfer of dam licenses from PacifiCorp to the Klamath River Renewal Corporation (KRRC) and California and Oregon.8 That transfer is contingent now only on ultimate FERC approval of dam removal, which is still under consideration. The FERC approval of transfer of licenses is, however, a key step toward removing the four dams, as the KRRC’s primary purpose is to remove the dams and restore the river. From July 20 to August 19, 2021, the FERC will accept comments for the scoping process under the National Environmental Policy Act (NEPA) for an analysis of dam removal itself.8 However, for over 15 years, the Klamath dam removal process has been intensely studied, including through a full FERC process and several NEPA and California Environmental Quality Act analyses as well as decades’ worth of research, reports, comments, and testimonies.8 All studies and analyses indicate that dam removal is safe and will significantly benefit salmon, Tribes, and water quality - without harming water supplies for farmers. Advocates hope that FERC will act quickly to finalize the Environmental Impact Statement because the Klamath salmon and basin communities cannot withstand further delays.8

Beginning in early May this year, Yurok and Karuk Tribes’ biologists have documented a massive fish kill of juvenile Chinook salmon on the Klamath due to warm waters and low flows.9 The Karuk Tribe in Northern California issued a “Resolution Declaring a State of Emergency Due to Climate Change” in response to record low precipitation and a massive juvenile salmon kill on the Klamath River.9

In a July 1 statement, the Karuk Tribe stated, “Hydrological conditions in the Klamath River Basin are the worst in modern history, although in recent years this has become an all-too-common refrain. Ecosystems and economies all along the California/Oregon border are strained to their breaking point. The massive fish kill currently underway in the Klamath River could result in losing an entire generation of salmon.”10

The Tribe also stated, “A complex of dams in the mid-Klamath disrupt natural flow patterns and cause warmer than normal water temperatures. This creates an ideal habitat for the parasite [such as the Ceratonova shasta (C. shasta)] to flourish downstream of the dams.”9 As a result, harmful conditions like toxic algae blooms and parasites are directly linked to the low flows and warm water conditions caused by the four Klamath River dams on the Klamath River and the Bureau of Reclamation’s mismanagement of the river that causes Klamath salmon to decline each year.9

(Image from Yurok Tribal Fisheries Program: “The Klamath River Fish Kill of 2002”)

The Karuk Tribe has long urged state and federal agencies to develop “long term solutions to recover fisheries and make the ecosystem resilient in the face of climate change.”9 Karuk Chairman Russell ‘Buster’ Attebery stated, “Dam removal will improve water quality, disrupt the habitat for disease vectors, and allow salmon to access historic spawning grounds. We are praying the fish can hang on until then.”9

Coastal ocean salmon fisheries supported by the Klamath River are also in severe decline for the same reasons. The entire Klamath Management Zone (KMZ) area of the ocean, spanning more than 200 miles of coastline in Northern California and Southern Oregon, has been nearly entirely closed to salmon fishing in 2020 and 2021 as a direct result of declining salmon runs from the Klamath River. Such closures cost salmon-dependent coastal communities tens of millions of dollars each year in lost jobs and income. If more juvenile salmon are lost to parasites and disease in the Klamath River each year, these valuable fisheries may never recover.

In an effort to speed the process of dam removal, Interior Secretary Deb Haaland issued a letter to the Federal Energy Regulatory Commission (FERC) supporting the removal of the four PacifiCorp dams stating, “Dam removal will restore salmonid fisheries, reestablish fish passage, improve water quality, and bring new recreation and economic opportunities to the Basin. Moreover, removal will advance the Biden-Harris administrations’ commitments to combat the climate crisis, increasing resilience to the impacts of climate change; protect public health; conserve our lands, waters, and biodiversity; deliver environmental justice; and fulfill the Federal Government’s trust and treaty responsibilities.”11 This river restoration project will have lasting benefits for the river, salmon, and communities throughout the Klamath Basin, including more than 420 miles of habitat and improved water quality without the threats of toxic algae and the abundant amount of parasite outbreaks.

Though every river system is different, the example of the Klamath shows what can be done to restore rivers and their valuable salmon runs, once the political will to make necessary changes exists. Restoring and reconnecting rivers builds much-needed resilience into ecosystems stressed today by a changing climate.

1. American Rivers: Klamath River, California, Oregon
2. CalTrout: Removal of Klamath Dams to Restore River Basin (April 27, 2021)
3. California Fish Passage Forum: Preparing the Klamath Basin for Dam Removal
4. Sacramento News & Review: Hopes for imperiled fish rise as FERC approves transfer of Klamath River dam license (June 19, 2021)
5. Yurok Tribal Fisheries Program: The Klamath River Fish Kill of 2002; Analysis of Contributing Factors (February, 2004)
6. The Sacramento Bee: Cutcha Risling Baldy: CA prioritizes profits over the health of ecosystem. Now, our salmon face extinction (June 27, 2021)
7. American Rivers: AR applauds Oregon and California, Tribes, PacifiCorps for river restoration leadership (November 17, 2020)
8. Save California Salmon: Dam Removal/FERC Hearing Fact Sheet (July, 2021)
9. CounterPunch: A Massive Fish Kill continues on Klamath River (June 10, 2021)
10. Karuk Tribe: Karuk Tribe Petitions CA Water Board to Regulate Scott Valley Water Users (July 1, 2021)
11. The Secretary of the Interior, Washington: Secretary Letter to FERC



 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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