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Blog & News


June 26th, 2024

Reshaping Landscapes: Klamath Dam Removal

Author: Taryn Tarquin
The Klamath River, a waterway winding over 250 miles through Oregon and Northern California, faces significant transformation. Construction is underway to restore the river’s ecosystem and address declining fish populations. The Klamath Dam Removal Project involves dismantling four hydroelectric dams: J.C. Boyle, Copco No. 1, Copco No. 2, and Iron Gate. While these dams once served as a power generation for the western US, electric power company PacifiCorp decommissioned them in 2010. However, breaching and removal of the dams did not begin until September 2023. Once completed, this project will be the largest dam removal and salmon restoration project ever undertaken globally.  
The Klamath River serves as an important ecological hotspot and a cultural cornerstone for indigenous communities. Historically, this river has been the birthplace of many of California’s salmon, with large coho (Oncorhynchus kisutch) and Chinook (Oncorhynchus tshawytscha) populations. The river is also home to steelhead trout (Oncorhynchus mykiss) and Pacific lampreys (Entosphenus tridentatus), which made it a popular fishing destination. Unfortunately, fishermen observed noticeable declines in fish populations following the construction of the dams. By the early 2000s, salmon populations had dropped by more than 90%.   
The construction of dams had cascading impacts on the habitat, drastically influencing fish populations. Low flow from Iron Gate Dam was a significant factor in the 2002 fish kill where over 34,000 Chinook salmon were found dead in the Lower Klamath River. Indigenous communities in the area feel that the river’s damming has severed their spiritual ties and disrupted traditional ways of life linked to the river’s natural flow. Yurok and Karuk tribal activists have been pushing for dam removal plans for nearly 30 years. In response to protests and costly federally mandated updates, PacifiCorp agreed to dam removal in 2016. For many Indigenous people, the undamming of the Klamath represents an opportunity to strengthen their ancestral connection to the river and maintain their fishing traditions. Once completed, hundreds of miles of aquatic habitat will be accessible for the first time in 100 years 
While activists celebrate the rewilding of the river, residents in nearby communities are hesitant to see the dams go. For the small town of Copco Lake, California, the breaching of the dams takes away their namesake lake. Community members fear that without the lake as a buffer, their town will be at higher risk of fire damage. Until now, the lakeshore was also used to collect water to fight nearby fires 
Over time, dam removal will enhance water quality and temperature, which will benefit aquatic organisms and the surrounding habitat. However, in the short-term, the river may appear muddier as large stores of sediment are released. Experts anticipated these results and have since observed improvements in nutrients, dissolved oxygen, and stream temperature, indicating the worst water conditions have already passed.  
Beyond removing the dams, there’s still a lot of work to be done before the Klamath Basin is fully restored. The current planting design for revegetating the river includes 96 different species, which will create more complexity and diversity in the surrounding habitat. Ideally, the revegetation effort will outcompete invasives and successfully establish along the river.  
Since the scale of the Klamath River dam removal is unprecedented, it will be interesting to observe changes in the ecosystem as it continues to heal. The three remaining dams – J.C. Boyle, Copco 1, and Iron Gate – are all being actively deconstructed. The deconstruction is expected to conclude in September of this year, which should allow anadromous fish to successfully migrate upstream to newly accessible habitat. Ultimately, time will be our guide in navigating future dam removal endeavors, while the Klamath Basin continues to teach us valuable lessons on environmental restoration and sustainable resource management. 
If you’re in the position to sign off on dam removal or riparian revegetation efforts, like those occurring along the Klamath, Great Ecology can help. Great Ecology has conducted a Cost-Benefit Analysis (CBA) to assess potential ecological and economic improvements resulting from the removal of three dams in the northeastern United States. Our analysis utilized biological surveys, GIS data, and published economic data to evaluate the state of the river before dam removal. We also gathered information from similar dam removal projects to predict project results. The CBA highlighted expected benefits, including access to historic spawning grounds for American shad (Alosa sapidissima) and improved water conditions due to the flushing of sediments.  
In addition, Great Ecology has been part of historic river revegetation efforts as part of the Emergency Watershed Protection Project, in Colorado. As part of this project, Great Ecology performed ecological assessments of damage compared to reference sites; worked with landowners, project partners, and regulatory stakeholders to reach agreed upon solutions; and developed and implemented revegetation efforts that included: native seed collection and propagation oversight, collection and installation of willow whips, leading volunteer revegetation efforts, erosion control best practices, revegetation monitoring, and more.