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SOS Blog

Save Our Wild Salmon

HWR Banner sockeye salmon with lesions image by Conrad GowellSockeye salmon with lesions dying from hot water in the Columbia-Snake River Basin ©Conrad Gowell


Welcome to the 2023 Hot Water Report: Warming Waters in the Lower Snake and Columbia Rivers.

During the summer, this weekly report provides an update on real-time water temperatures in the lower Snake and Columbia River reservoirs via graphs and analyses, a summary of the highest weekly water temperatures at the forebay/reservoir of each dam, and a monthly status of adult returns for different salmon and steelhead populations as they make their way back to their natal spawning grounds. We’ll report first-hand from scientists, Tribal members, fishing guides, advocates, and other experts about the challenges facing these rivers – and our opportunities to improve and restore them - in order to recover healthy, resilient fish populations and the benefits they deliver to Northwest communities, other fish and wildlife populations (including the critically endangered Southern Resident orca), and ecosystems.

Many once-abundant anadromous fish populations in the Columbia-Snake River Basin are on the brink of extinction today due primarily to harms caused by federal dams and their warming reservoirs. The Columbia-Snake federal hydro-system harms and kills both juvenile and adult fish in multiple ways, including by elevating water temperatures in the summer months in their large, stagnant reservoirs. These cold-water fish begin to suffer harmful effects when water temperatures exceed 68° Fahrenheit.

This week, on the lower Snake River, the reservoir behind the Ice Harbor Dam registered the highest water temperature at 72.01°F – over 4 degrees above the 68°F “harm” threshold. Between 72-73°F water temperatures, salmon migration can stop altogether. Salmon that have stopped or slowed their migration, languish for days or weeks in warm water and begin dying from thermal stress and disease. In Issue 4, we’ll provide insight on how salmon and steelhead declines severely impact the recreational and sportfishing economy and fishing opportunities. Restoring a free-flowing lower Snake River by removing the four dams will advance economic opportunities for sport and recreational salmon industries, restore 140 miles of river for recreation activities, and unlock the major earnings potential of the Snake River Basin. (NOTE: While this HWR issue focuses on recreational fishing, it must be emphasized that salmon also deliver very important economic and cultural benefits for commercial and Tribal fishing communities as well).

A restored, healthy, and resilient lower Snake River is necessary to uphold our nation's promises to Tribes and sustain salmon populations in perpetuity. Dam removal is a huge salmon restoration opportunity as it will reconnect the Northwest’s most emblematic fish to over 5,500 miles of pristine, cold-water river and streams in Idaho, Oregon, and Washington.

The Hot Water Report is a joint project of the Save Our wild Salmon Coalition, American RiversAssociation of Northwest SteelheadersColumbia RiverkeeperEarthjusticeEndangered Species CoalitionEnvironment OregonIdaho Conservation League, Idaho Rivers United, Natural Resources Defense Council, National Wildlife FederationNorthwest Sportfishing Industry AssociationOrca NetworkSierra Club, Snake River Waterkeeper, Wild Orca and Wild Steelhead Coalition.

II. READING THE DATA - Water Temperatures in the Lower Snake and Columbia Rivers

Figure 1. Lower Snake River Water Temperatures - 2023 Daily Average and 10-year Average. Click on the image to view the graph.

Introduction to the data:
The daily average temperature at the four reservoir forebays (measured with sensors stationed at various depths below the reservoir surface, immediately upstream from the dam) in the lower Snake River (above) and the lower Columbia River (below) for 2023 is represented with solid lines and the 10-year average (2013 - 2023) temperatures with dashed lines of the same color. The dotted line across the graph represents the 68°F “harm threshold” for adult and juvenile fish.

The longer and the higher these temperatures rise above 68°F, the greater the harm, including: migration disruption, increased metabolism, increased susceptibility to disease, reduced reproductive potential (by reducing egg viability), suffocation (warm water carries less dissolved oxygen), and in the worst case - death.

Reservoirs are large, stagnant pools that can absorb enormous amounts of solar radiation, and cause waters to warm. These waters inundate and destroy diverse micro-habitats that healthy rivers support, including cold-water refuges that salmon and steelhead rely upon during their migration. Without these vital pockets of cold water, salmonids cannot rest and recover on their journeys – adults moving upstream to spawn and juveniles moving downstream to the ocean. Rising temperatures and reductions in snowpack in recent decades due to climate change create warmer waters, which results in lower survival and reduced reproductive success for salmon and steelhead.

LCR July 25Figure 2. Lower Columbia River Water Temperatures - 2023 Daily Average and 10-year Average. Click on the image to view the graph.

Discussion of data:
Since April, temperatures in the lower Snake River and the lower Columbia River reservoirs have steadily increased. As Figure 1 shows, this week, the reservoir behind the Ice Harbor Dam had the highest average temperature of 71.99°F from July 19 - July 25. The Lower Monumental reservoir had the second highest average temperature of 70.53°F on July 23.

As Figure 2 shows, this week, the reservoir behind the Bonneville Dam, and The Dalles Dam registered the highest average temperature of 72.5°F. Both juvenile and adult salmon are now experiencing water temperatures above the 68°F “harm” threshold in several of the reservoirs they pass.

Below, we present the weekly high temperatures for each reservoir on the lower Snake and Columbia rivers for July 19 - 25

A note on the data: The 2023 lower Snake River and lower Columbia River water temperature data presented in the Hot Water Report are collected from the Columbia River DART program by Columbia Basin Research, University of Washington, using data courtesy of the U.S. Army Corps of Engineers (USACE). The 10-year average water temperature data is courtesy of the Fish Passage Center. There is no data available for the Lower Monumental 10-year average water temperature, and McNary reservoir water temperature data is collected from USACE with current available data. Graphs and tables were assembled by SOS Staff.


LSR High temps 719 25

This week, on the lower Snake River, the reservoir behind the Ice Harbor Dam registered the highest water temperature at 72.01°F on July 22, and the Lower Monumental Dam registered the second highest temperature at 70.99°F on July 23.

LCR High temps 719 25This week, on the lower Columbia River, the Bonneville reservoir and The Dalles reservoir registered the highest water temperature at 72.86°F.

IV. How Snake River salmon declines impact the Northwest recreational fishing economy

Salmon Neil Ever Osborne

Not long ago, the Columbia-Snake Basin supported the most diverse and abundant salmon and steelhead populations in the continental United States. Historically, an estimated 10-16 million wild salmon and steelhead annually entered the Columbia River Basin to spawn, with 2-4 million Spring/Summer Chinook and B-run steelhead utilizing the Snake River watershed.

Salmon are not only vital to Pacific Northwest ecology, culture, and food but also contribute to a thriving fishing economy. However, since the completion of the four lower Snake River dams in the 1970s, annual returns for salmon and steelhead have persisted far below the recovery goals necessary to remove them from the protections of the Endangered Species Act (ESA), and the dams continue to threaten the existing regional fishing economy. With devastating and record-low salmon and steelhead returns, fishing businesses and communities suffer due to the loss of economic opportunities these fish would otherwise provide.

“There's no longer such a thing as a full-time fishing guide. We don't get to make a full-time living at this any longer like I did 20 years ago. Snake River salmon and steelhead are keystone species and iconic species of the Pacific Northwest, drawing visitors from all over the world because those populations are decimated on the East Coast and in Europe. The West Coast is the last remaining stronghold of wild salmon and steelhead.”

– Bob Rees, recreational fishing guide and executive director for the Northwest Guides and Anglers Association

Restoring a free-flowing Snake River through the removal of its four dams is our only feasible option to rebuild salmon and steelhead abundance. It will generate hundreds of millions of dollars annually from restored fishing opportunities in many rural communities and rebuild a robust and prosperous salmon economy.

Loss of economic opportunities for Recreational Fishing and Sportfishing in the Northwest

Snake River salmon and steelhead populations support thousands of ocean, sportfishing and guide jobs in often-rural communities throughout the Northwest. Recreational fishing for salmon and steelhead in the Columbia and Snake River Basin currently supports a vital economy in the Northwest. Recreational fishing involves spending on boats and related fishing gear (rods, reels, tackle, etc.), as well as travel expenses (food, gas, lodging, etc.) in and around river and coastal communities. This economic output ripples through local communities, helping to foster jobs, economic stability, and growth.

recreational economy 4The American Sportfishing Association’s ‘Economic Contribution of Recreational Fishingreport shows the number of jobs that are dependent on salmon and steelhead (Table 1). In combining the number of recreational fishing jobs in Washington, Oregon, and Idaho, salmon and steelhead are key in sustaining over 29,420 jobs and have a positive economic influence in the Northwest.

Increasingly, recreational and sportfishing businesses are faced with emergency closures and a limited number of days to fish in order to protect ESA-listed salmon and steelhead. A majority of recreational and sportfishing jobs have been negatively impacted by the decline of salmon and steelhead and loss of economic opportunity. Communities who benefit from salmon also suffer economically, culturally, and socially; such as hotels, restaurants, shops, and other businesses that rely on fishing.

"I made a choice to stop guiding due to decreased run size of steelhead populations. Seasons closed, businesses slowed, and my livelihood suffered. But more than anything, I felt guilty harassing a population that was already so depressed.

The main issue, however, is not my guiding or fishing. The main issue is that salmon and steelhead need rivers. The dams have reduced the Snake to a series of lakes."

– Ian Faurot, McCall, ID

The lower Snake River dams and their hot water reservoirs create hazardous conditions for salmon and steelhead as they migrate. The dams and reservoirs on the lower Snake River continue to be the main obstacle to recovery for salmon and steelhead. In 2015, some of the earliest and hottest weather on record produced warm river temperatures that killed more than 95% of all adult sockeye salmon returning to the Columbia Basin. In recent years, state agencies have had to severely limit or cancel entire fishing seasons to protect the dwindling fish headed for the Snake Basin.

In 2019, anglers only had about seven days of a meaningful opportunity for salmon in the first seven months on the Columbia and Snake rivers. It was a record low of economic benefit to communities over the last 16 years, and 2020 produced equally poor opportunities.

In 2021, regional fish and wildlife agencies recorded one of the smallest counts of adult spring Chinook salmon in a generation in the Snake and Columbia River Basin, and Snake River steelhead saw the lowest returns in history, forcing emergency fishing closures in Washington and Oregon.

This year, due to early snowmelt, lack of spring rain and low streamflows, hot water temperatures in the lower Snake River, salmon and steelhead are overwhelmed by the tortuous conditions created by these federal dams and their warming reservoirs, thus imperiling their final journeys to their natal spawning grounds. This week, the Ice Harbor reservoir reached the highest water we have seen so far this year at 72.01°F – over 4 degrees over the 68°F “harm” threshold. Between 72-73°F water temperatures, salmon migration stops altogether or is slowed. Salmon can languish for days or weeks in hot water and begin to die from thermal stress and disease.

fishing Neil Ever Osborne

"During my relatively short time guiding, I have seen a steep decline in yearly averages to the point of full river closures up and down the Columbia corridor. So much so that I have lost full seasons and opportunities due to low steelhead returns and morally feeling unethical to target such a struggling fish."

– KynsLee Scott, fly-fishing guide, Missoula, MT

A letter signed by hundreds of businesses and individuals in the Pacific Northwest who depend upon robust fisheries, outdoor recreation and healthy rivers, recently urged immediate action from the Biden Administration to ensure the fishery resources that industries, Northwest Tribes, and imperiled Southern Resident Orcas depend upon are restored to abundance. 

The letter states “dam removal must be a ‘centerpiece action’ for a durable long-term solution to salmon recovery in the Snake River Basin, and investments must be identified and prioritized to ensure economic development opportunities for the recreation, tourism, and fishing industries that rely on abundant salmon and steelhead populations, and healthy free-flowing rivers. By restoring the lower Snake River and replacing their services, we will regain 140 miles of riverfront on each side of the river to fish, hunt and recreate while also modernizing and expanding agriculture, transportation and clean energy infrastructure in the Columbia Basin.”

Opportunities for anglers have declined drastically in recent years, which keeps families from recreating outside together and the sportfishing community from importing critical revenue to rural communities during shoulder tourist seasons. The benefit of economic opportunities for recreational fishing would increase when the dams are breached, and an increase in harvestable salmon abundance will follow.

Restoring a free-flowing lower Snake River

Rally for Salmon 2022 Jeff Dunnicliff

“I look forward to the day where I can share the joy of fishing for salmon and steelhead with my guests, and that day will come as soon as we breach the four lower Snake River dams and replace the services they provide. I don't think that we should look at the removal of the four lower Snake River dams as an expense but rather an investment in the economy and the ecology of the area.” 

– Mandela van Eeden, Communications Coordinator for the National Wildlife Federation Outdoors; Artemis sportswoman; and part-time fishing guide and river guide

Restoring a free-flowing lower Snake River by removing the four dams will advance economic opportunities for sport and recreational salmon industries, restore 140 miles of river for recreation activities, and unlock the major earnings potential in the Snake River Basin.

Northwest Sportfishing Industry AssociationNotably, Senator Murray and Governor Inslee’s final Lower Snake River Dams: Benefit Replacement Report recognized that with a free-flowing lower Snake River and restored salmon fisheries in the Columbia-Snake Basin, recreational fishing (a major economic driver of rural communities) could generate up to $1 billion annually in additional regional personal income benefits and support up to 25,000 new family-wage jobs.

A restored lower Snake River will create abundant fishing opportunities, new network of waterfront parks and trails for hiking, biking, hunting, fishing, and other recreation. It will also draw visitors from across the nation and world to see thriving salmon and steelhead. Interest in the restored river will generate diverse recreation-based economic activity, especially in inland Northwest communities like Lewiston, Idaho and Pasco, Washington.

Removing the four lower Snake River dams and replacing their services is our only viable long-term solution to Snake River salmon and steelhead recovery and our only opportunity to secure economic development opportunities for recreation and sportfishing that heavily rely on abundant salmon and steelhead populations.

“Salmon fishing supports thousands of jobs and is an important part of our Northwest way of life. But fishing businesses are struggling for survival today, and the rock bottom runs and fishing closures have been devastating. We need all of our elected leaders leaning in and working on real solutions.”

– Liz Hamilton, executive director for the Northwest Sportfishing Industry Association 


V. Read ‘Economic development for rural communities and recovery for imperiled salmon’ op-ed by Dan McDonald, president and board chairman of the Yakima Bait Company, based in Granger, Washington.

Restoring a free-flowing lower Snake River – and replacing the dams’ services with alternatives – is critical for protecting its fish from extinction. It also represents our region’s greatest opportunity to safeguard Washington’s recreational fishing industry that supports almost 15,000 jobs and an annual economic output of $2.3 billion every year.

This kind of comprehensive approach – removing these dams and replacing their services – also represents the greatest economic development opportunity our region has seen in decades. With bi-partisan leadership in the Northwest and an administration in Washington D.C. that’s committed to expanding clean energy resources and modernizing other critical infrastructure, we have a once-in-a-generation opportunity right now to fix some big problems and modernize aging infrastructure.”

Read the full op-ed here.


  1. View the past Hot Water Report issues here: Hot Water Reports - Compiled
  2. The Lewiston Tribune: Sockeye begin epic Northwest journey (July 22, 2023)
  3. East Oregonian: Other views: The science is clear on restoring wild salmon in the Snake River Basin (July 22, 2023)
  4. Idaho Capital SunSalmon politics in motion: Responsible momentum is building in Idaho, Pacific Northwest (July 27, 2023)
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