Dams Versus Salmon on the Snake River

Environment Policy Brief #130 | By: Timothy T. Loftus, Ph.D. | December 20, 2021

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Policy Summary

This past October, the Northwest News Network reported that a coalition of conservation groups, the Nez Perce Tribe, and the State of Oregon reached an agreement with the Biden Administration and federal agencies to pause, until next summer, long-running litigation over the operations of Snake River dams within the Columbia River Basin. With a growing chorus of elected officials willing to either support or consider dam removal, and new leadership in our nation’s capital, a fresh round of negotiations over the ongoing impact of dam operations on salmon populations are now getting underway. The expectation is for a new plan to be crafted that will help prevent salmon from disappearing in a river basin where they’ve existed for millennia.

The dams at issue, four of them, are situated on the lower Snake River in the state of Washington: Lower Granite Dam, Little Goose, Lower Monumental, and Ice Harbor. The multi-purpose dams are located just above the Snake’s confluence with the upper Columbia River and are operated by the Army Corps of Engineers. The hydropower generated is managed by the Bonneville Power Administration. The Snake River is the largest tributary to the Columbia River and the former’s watershed includes Nex Perce tribal lands. 

Like many dams, these four enable several benefits to be had by people in the region: water supply for agricultural irrigation, transportation for agricultural (mainly) commodities, and hydropower generation that has made for affordable electricity. The emissions-free power generated is now especially beneficial given national and international efforts to reduce greenhouse gas emissions.

Decades of dams situated throughout the Columbia and Snake River Basins, however, have had a severe impact on salmon and steelhead trout to the point that these anadromous fishes are relatively scarce where once they were very abundant.

The National Wildlife Federation and other conservation groups are fighting for the fish to simply survive as an integral part of an aquatic ecosystem where salmon, steelhead, and other impacted species play a significant role. The Nez Perce Tribe aims to maintain healthy populations and an abundance of salmon and steelhead as a longstanding element of their culture and means of subsistence living. The Tribe also possesses a treaty right, an agreement with the federal government, that guarantees access to salmon. That treaty right has been compromised since dam operations commenced in the mid-20th Century and the collection of dams have proven to be largely responsible for decimating seasonal salmon runs and population numbers.

Critically, many key elected officials are now onboard with taking a fresh approach to saving the salmon from extinction. Rep. Mike Simpson (R-ID), for example, is now on record stating, “My staff and I approached this challenge with the idea that there must be a way to restore Idaho salmon and keep the four lower Snake River dams. But after exhausting dozens of possible solutions, we weren’t able to find one that could control poor ocean conditions, warming rivers, and the four lower Snake dams. In the end, we realized there is no viable path that can allow us to keep the dams in place.”

On October 22, 2021, U.S. Senator Patty Murray (D-WA) and Washington state Governor Jay Inslee issued a joint statement in support of a federal-state process for exploring the means to replace the benefits provided by the lower Snake River dams, sufficient to support dam removal (i.e., breach) as part of salmon recovery. The process will yield recommendations by July 31, 2022. Their joint statement was immediately followed by another statement of support for the joint process on Snake River salmon recovery by U.S. Senators Ron Wyden (D-OR) and Jeff Merkley (D-OR).

Policy Analysis

It’s well documented that dams fragment river systems, interfere with fish migrations, and have other consequences for nature. This is especially true in the Pacific Northwest and California where historic salmonid abundance and diversity has been in consistent decline for decades. 

To be sure, there are other factors that contribute to diminished salmon populations including historic logging practices, agricultural activities, and urban development to name a few, but dams present formidable obstacles for fish to overcome despite efforts to accommodate them with fish ladders and other strategies. Climate change is an additional stressor for salmon when taking their anadromous life cycle into account.

For this current round of negotiations to succeed in producing a new solution, one that might involve dam breaching or removal, plans for replacing the primary benefits of dams with other means must be proffered. For example, can the electrical power generation be replaced without causing undue hardship on ratepayers? 

The not-for-profit organization, Dam Sense, reports that power production on the lower Snake River dams is a fraction of total capacity and is particularly limited during peak summer and wintertime demand periods.

 It’s contribution to the regional power grid, therefore, can theoretically at least be replaced. With other forms of renewable energy production increasingly coming online, it’s possible that the power generated by these dams will be the benefit that is most tractable to replace.

River navigation, made possible or at least enhanced by dams, has historically been an economical form of transport for bulk commodities and containerized cargo. The Port of Lewiston (POL) Idaho, located on the lower Snake River, is the most inland port on the west coast. 

The POL is a multimodal port with good access to the primary railway in the region and nearby highways. Shipping report data from the POL indicate a downward trend (1991-2018) in wheat shipment tonnage, a total loss/suspension of container shipments during the same period, and a dramatic increase since 2016 in break bulk cargo. Grain shipments are the number one export leaving the Lower Granite Pool with ten percent of all US wheat exports going by barge through the Snake River dams according to the POL.

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Photo taken from: Oregon Business / Data from U.S. Forest Service      (click or tap to enlargen)

Ice Harbor Lock and Dam, completed in 1962, holds back Lake Sacajawea that is the source of irrigation water for approximately 47,000 acres of farmland as tabulated by the US Bureau of Reclamation. Diversion quantities associated with these private irrigation projects are not publicly available but can potentially be replaced with a combination of intakes on the river itself, alternate sources of water such as reclaimed wastewater, and modifications to cropping patterns and practices.

Lake-based recreation enabled by dams in the Columbia River Basin will also be impacted, but this activity was not the primary reason for which Congress authorized the construction of these dams. Local recreation-based economies are important, nonetheless, and would have to evolve to become river-based if possible and/or relocate to other lakes in the region. The report due next July might reveal how the recreation benefit of artificial lakes compares to other benefits studied in terms of both economic value and potential for replacement if recreational activities are deemed to warrant this level of consideration.

Another key component of this issue is the matter of treaty rights that the US Government signed with the indigenous peoples in the Pacific Northwest nearly 170 years ago. In exchange for the land that was amassed for newly arriving settlers, the US Government gave tribes the right to natural resources including fresh water and salmon. The Nez Perce Tribe is among the plaintiffs in the current agreement for short-term operations of the Columbia River System and related stay of the litigation.

While dam removal, should that recommendation be made and implemented, doesn’t guarantee that salmon and other fish populations will rebound and thrive (see, for example the Washington Policy Center’s take on the matter), leaving the four dams in place will almost certainly guarantee a continuation of both litigation and a depleted state of Snake River salmon runs. 

The situation demands fresh thinking and a new approach. Dam removal elsewhere (e.g., Elwha and Glines Canyon Dams on the Olympic Peninsula, two dams on the Penobscot River in Maine) has proven to be beneficial for both fisheries and riparian ecosystems and provides proponents of dam removal with ample reason for hope should the lower Snake River dams be scheduled for removal.

Lastly, any cost/benefit analysis of dam removal will be incomplete without accounting for the ongoing social costs associated with diminished biodiversity related to lower Snake River dam operations. 

Determining the value of ecosystem services that salmon generate and determining the full cost associated with their diminishment are essential components for a comprehensive accounting of the matter at hand. Ecosystem-service valuation for a full-cost accounting of the loss of those services will help inform decision makers in this case and is part of the toolbox for stemming the tide of the extinction crisis that is underway globally.

Engagement Resources​

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Washington Water Trust. Washington Water Trust (accessed December 14, 2021)


United Nations Sustainable Development Goals. Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services. UN Report: Nature’s Dangerous Decline ‘Unprecedented’; Species Extinction Rates ‘Accelerating’ – United Nations Sustainable Development (accessed December 14, 2021)


Nez Perce Tribe. Cultural Resource Program. Nez Perce Tribe Cultural Resource Program (nezpercecultural.org) (accessed December 14, 2021)

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US Army Corps of Engineers. Lower Snake River Dams.  Walla Walla District > Missions > Lower Snake River Dams (army.mil) (accessed December 14, 2021)


“Totem Salmon: Life Lessons From Another Species.” 1999 by Freeman House. Boston, MA: Beacon Press.

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