Sockeye 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 federal 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 - fish that hatch in freshwater, go to sea, and return to freshwater to spawn - 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 72.50°F on July 26 – over 4 degrees over the 68°F “harm” threshold. This week marks the second week, where the lower Snake River reached 72 degrees, a temperature that can stop salmon from migrating. In Issue 5, we’ll provide insight into how steep salmon declines in the lower Snake River dams and elsewhere in the Columbia Basin have impacted commercial salmon fisheries. The restoration of Snake River salmon by removing the four lower Snake River dams will, among many other benefits, expand economic opportunity for commercial salmon fisheries in the ocean and in Columbia-Snake River Basin by rebuilding runs of the salmon and steelhead, which Northwest Tribal, sport, and commercial fishing depend on.
Importantly, a restored, healthy, and resilient lower Snake River is necessary to uphold our nation's promises to Tribes and sustain salmon populations in perpetuity. Lower Snake River dam removal is our greatest salmon restoration opportunity on the West Coast today; 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 Rivers, Association of Northwest Steelheaders, Columbia Riverkeeper, Earthjustice, Endangered Species Coalition, Environment Oregon, Idaho Conservation League, Idaho Rivers United, Natural Resources Defense Council, National Wildlife Federation, Northwest Sportfishing Industry Association, Orca Network, Sierra Club, Snake River Waterkeeper, Wild Orca and Wild Steelhead Coalition.
II. READING THE DATA - Water Temperatures in the Lower Snake and Columbia Rivers
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 absorb enormous amounts of solar radiation, and cause the water 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.
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 72.03°F from July 26. The Lower Monumental reservoir had the second highest average temperature of 70.91°F on August 1.
As Figure 2 shows, this week, the reservoir behind The Dalles Dam, and John Day Dam registered the highest average temperature of 72.14°F. Both juvenile and adult salmon are experiencing water temperatures above the 68°F “harm” threshold in several of the reservoirs they pass.
Below, we present the weekly high water temperatures for each reservoir on the lower Snake and Columbia rivers for July 26 - August 2.
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.
III. WEEKLY HIGH WATER TEMPERATURES: July 26 - August 2
This week, on the lower Snake River, the reservoir behind the Ice Harbor Dam registered the highest water temperature at 72.50°F on July 26, and the Lower Monumental Dam registered the second highest temperature at 71.26°F on August 1.
IV. Salmon declines impacting Northwest Salmon Fishing Opportunity
Columbia-Snake River Basin salmon have historically supported fishing businesses and the related shoreside jobs that are important, long-standing contributors to Washington’s coastal communities and economy. However, with Snake River salmon on the brink of extinction, fishing opportunities in the Columbia and Snake rivers and on the ocean currently are limited in order to protect these imperiled populations. Restoring the lower Snake River by removing the four dams will recover Snake River salmon and steelhead populations and is our greatest opportunity to save and rebuild the declining runs of salmon and steelhead, which many Northwest Tribal, sport, and commercial fishing depend. Additionally, rebuilt salmon populations can once again serve as a critical source of nutrition for Endangered Species Act-listed Southern Resident orcas and more than 100 other species of fish and animals.
Loss of Economic Opportunities for Commercial Fishing Families in the Pacific Northwest
Salmon were once the pillar of commercial fisheries on the West Coast. Commercial salmon troll fishery—composed of small ocean-going boats, independently owned and operated, that catch Chinook salmon one at a time on hook and line gear—depends upon the number of Columbia-Snake River Basin Chinook that survive to become adults.
The four lower Snake River dams and their reservoirs are a leading cause of mortality for these fish. The dams have dangerously extended salmon’s travel time to the ocean. Before the dams were constructed, juvenile salmon could travel—pushed by the cold, clear spring freshet—from their natal spawning grounds to the Pacific Ocean in as little as a week. Today, for those fish that survive the often-lethal out-migration through the federal hydro-system, it now requires more than a month for the fish to actively swim to the ocean. Wild salmon populations are currently at just 1-3 percent historic run levels, and in the past five years, wild Snake River Spring/Summer Chinook numbers averaged less than half of their total return when the fish were first listed under the ESA in 1992. Washington and Oregon’s fisheries managers closely monitor salmon fishing week to week and make in-season catch adjustments necessary to protect and sustain the fish over time.1 The extremely low returns of adult salmon these days often leads to emergency commercial fishing closures with only 24 hours notice. Fishing closures may last for a few days or weeks or until the following year.2,3
For some historical perspective, consider this: In 1949, the State of Washington Department of Fisheries’ managers warned about the harmful effect of hydropower development in the Snake River Basin and predicted the four dams proposed at that time would cause devastating impacts to Snake River-origin fisheries and communities that rely on fishing jobs.4 Policymakers failed to heed the scientists' admonitions and build the dams anyway. For decades now, salmon populations and the commercial fishing families that rely on them have declined and suffered as predicted almost a century ago. From 1971 to 1975, the salmon catch of the troll fishery was valued at an average of $21.8 million annually,5 but in 2022, the catch was worth $3.1 million;6 this is over 90% loss of economic value. In 1978, there were 3041 salmon fishermen, licensed and based in Washington, operating salmon trollers in the coastal waters across Washington to Southeast Alaska.7 By 2018, the number had fallen to 102 boats, and in 2022, the number fell to 79 boats.8
The devastating economic losses for the commercial fishing fleet are also felt in coastal communities as jobs generated and/or supported by the salmon fishing industry disappear. Commercial salmon fisheries support land based jobs in, for example, fishing gear stores, boat and engine repair businesses, grocery stores, restaurants, and marinas, and bring tax dollars into communities to support local investments such as schools, hospitals, and vital infrastructure. Today, as fewer harvestable salmon are available, there has been a loss of approximately 6,000 jobs in the West Coast fishing fleet and more in onshore businesses that provide services, supplies, and equipment to the fleet as well as investments to local communities and infrastructure.9
In recognition of the extinction crisis facing many Northwest salmon populations, more than 229 food professionals - chefs, brewers, market owners, farmers, fishermen, and others from across Washington State – sent a letter in 2022 to Gov. Jay Inslee, Sen. Patty Murray, and Sen. Maria Cantwell to thank them for their past efforts to protect salmon and encouraged them to develop and deliver a comprehensive solution that recovers healthy salmon populations by removing the four lower Snake River dams, replace their services, and invest in communities in a manner that brings everyone forward together.
The letter states, “salmon is much more than a fish; it is one of our most valued business partners. The health and availability of salmon here in the Pacific Northwest impacts our bottom line and our ability to maintain good jobs for the people we employ, provide healthy food for our customers, and feed our own families.” The letter stresses that “decades of trial and error have demonstrated that well-managed fisheries by themselves are not enough to assure sufficient numbers of salmon to drive the economic engine, jobs, and businesses they support.”
“When I was a kid in the ‘70’s I remember how the surface shimmered red when the sockeye came home to spawn. I also sadly remember the story of Lonesome Larry, the only sockeye that made it home to the Salmon River’s headwaters. This was in 1992, and my heart broke when I heard the news. I’m passionate about restoring salmon abundance. This isn’t a debate about borders, or what side of the state you are on. It’s about prioritizing healthy salmon and healthy communities!”
– Chef Robin Leventhal, instructor at the Wine Country Culinary Institute in Walla Walla.
Protecting, restoring, and reconnecting healthy and resilient habitat is essential to Snake River salmon and steelhead survival and recovery. And it is imperative for the Tribal cultures, coastal communities, and fishing families that rely upon the fish.
A free-flowing river benefiting commercial fishing and coastal communities
“The four lower Snake River dams are doing more than holding up fish and making the water warmer, they are impacting the economies of coastal communities and inland communities above them. When we remove the dams and replace their services, we need to make sure Snake River salmon, water, and other resources are healthy and abundant for Tribes, farmers, fishermen, and others to use.”
– Amy Grondin, Commercial Fisherman and Co-owner of Duna Fisheries
The loss of jobs and economic opportunities for commercial salmon fishing families provide evidence over fifty years of hardship due to the four lower Snake River dams. The restoration of Snake River salmon by removing the four lower Snake River dams offers great economic opportunity for both the ocean salmon troll and Columbia-Snake River Basin commercial fisheries and many, many others.
View the past Hot Water Report issues here: Hot Water Reports - Compiled
1. Save Our wild Salmon: The Importance of Commercial and Recreational Fishing in WA, 2020. pg.6
2. Spokesman-Review: Helen Neville: The need to breach the Lower Snake River dams: A look at 2022 fish returns
3. Save Our wild Salmon: The Importance of Commerical and Recreational Fishing in WA, 2020 pg.6
4. Alvin Anderson, State of WA Dept of Fisheries Annual Report for 1949
5. Pacific Salmon Commission, Economic impacts of Pacific Salmon Fisheries, 2018
6. Pacific Salmon Commission, Economic impacts of Pacific Salmon Fisheries, 2022
7. Pacific Salmon Commission, Economic impacts of Pacific Salmon Fisheries, 2018
8. Pacific Salmon Commission, Economic impacts of Pacific Salmon Fisheries, 2022
9. Lower Snake River Dams: Benefit Replacement Report, August 2022