Monday January 27, 2025
After the largest dam removal in history, the Klamath River – at a newly uninterrupted 257 miles in length – now holds the title for the longest undammed river in California. Iron Gate Dam, located in Siskiyou County, California was the last of four dams on the Klamath River to be demolished, marking a monumental moment for Tribes with ties to the land surrounding the river. While the Klamath made headlines when the Copco #2 dam was removed in summer 2023, the full story began long before. The first half of the 20th century saw a boom in infrastructure, including thousands of large dams that were built across California to meet the resource needs of an ever-expanding population. Over a 46-year period, from 1918 to 1964, the four lower Klamath hydroelectric dams were constructed. Less than 20 years later, sacred native salmonids, central to many of the river’s Tribal nations, were listed as endangered. Tribes, including the Yurok, Karuk, Hoopa and others, rely on these fish for cultural purposes and as a primary food source through the cold winter months. Once a vibrant river that boasted abundant salmon populations, and the third largest salmon producer on the West Coast, the dammed Klamath was now home to salmon that struggled for survival.
In the summer of 2002, an estimated 60,000 adult salmon died due to various environmental conditions. The “Analysis of Contributing Factors”, conducted by the Yurok Tribal Fisheries Program, concluded that low flow rates from Iron Gate Dam caused crowded conditions, and warm water temperatures. These conditions created an ideal environment for the parasite Ichthyophthirius multifiliis (commonly known as ich) and the bacterial pathogen Flavobacterium columnare (columnaris), and this outbreak was attributed to the high number of fish killed in 2002. This devastating event continues to haunt Klamath River communities and sparked the creation of the Bring the Salmon Home campaign. Legal battles ensued over the next 14 years until a settlement agreement was reached to remove the dams.
Starting in 2019, in-depth baseline environmental data were collected for comparison and monitoring after dam removal. Environmental DNA, water quality assessments, native seed collection, and sensitive species relocation were just a few of the initial activities that kicked off the restoration of the Klamath River valley. Many spectators gathered excitedly as the first dam was breached in January of 2024. Great efforts were made to systematically remove each dam, manage sediment release, and transport substrate to limit impacts on salmon and other native species. Revegetation began immediately after drawdown, making for bright and colorful river banks in the following spring. The final dam fell in early October of 2024, releasing the Klamath River to its historical path.
The restoration of the Klamath River is an ongoing effort, requiring that a variety of monitoring and stewardship activities be continued into the future to ensure the long-term health of the ecosystem. Regular assessments of water quality, sediment transport, and aquatic species populations are essential to track the river’s recovery. Long-term monitoring of salmon reproduction and migration patterns will help evaluate the success of habitat restoration efforts in bolstering anadromous fish survival. Adaptive management strategies will also be crucial in addressing emerging challenges such as invasive species, pathogen exposure, or climate-related changes in water flow and temperature.
Collaborative efforts involving the Karuk Tribe, the Yurok Tribe, other Klamath Tribes, and the U.S. Geological Survey also focus on continuously monitoring water quality and sediment movement. The role of Indigenous knowledge and stewardship has been central to the restoration process. The Yurok Tribe’s restoration crew led efforts in native plant seed collection and, along with Resource Environmental Solutions, were the first to replant the mudflats after dam removal and ground preparation. These contributions have emphasized the importance of traditional ecological knowledge with modern scientific approaches, fostering a holistic vision for the river’s revival as many stakeholders are working to bring salmon back to the Klamath.
Stakeholders were thrilled to witness the return of salmon to a habitat that was lost to them for 60 years. As the first fall-run Chinook salmon passed the footprint of what was previously Iron Gate Dam, hope filled the hearts of Indigenous communities and the many partners who made this happen. Only two weeks later, these same salmon were already being spotted in Southern Oregon. Modeling of the Klamath River mainstem and six tributaries predicts that, despite various constraints, salmon will likely have successful reproduction rates.
The process of dam removal is unique in every system as dams serve different purposes in different communities. For the Klamath River basin, the economic implications of dam removal are noteworthy as restored fisheries could bring back commercial and recreational fishing opportunities and bolster local economies. Revitalized ecosystems may also enhance tourism and outdoor recreation, drawing visitors who are eager to experience the restored natural beauty of the river valley. As other hydroelectric dams reach the end of their lifespan, the Klamath Dam removal project has the potential to serve as a valuable example for other dam restoration efforts.
Header Image Caption: A scenic view of the Salmon River, a major tributary of the Klamath and a hotspot for many spawning salmon and steelhead. (Photo courtesy of Alyssa Owen)
This post was featured in our weekly e-newsletter, the Fish Report. You can subscribe to the Fish Report here.