The Klamath River Renewal Corporation’s (KRRC) plans to remove four dams on the Klamath River in the US has taken a major step forward with the issuance of key documents from the California State Water Board.

The plan – the largest dam removal project in the US – would re-open 360 miles of the Klamath River and its tributaries to salmon. It involves the removal of the removal of the J.C. Boyle, Copco No. 1, Copco No. 2, and Iron Gate dams.

The four dams, located along the river in southern Oregon and northern California, impound water for hydroelectric facilities with a combined capacity of 163MW. The facilities include earthfill embankment and concrete gravity dams; a variety of intake, gate, and spillway types; a variety of water conveyance schemes including pipelines, tunnels, canals, and woodstave and steel penstocks; and powerhouses containing Francis-type turbines.

JC Boyle dam

KRRC aims to remove these dams in a bid to restore volitional fish passage up and down the Klamath River, restore formerly inundated lands and channels, and implement required mitigation measures in compliance with all applicable federal, state, and local regulations. 

Last week, the State Water Board issued a Final Water Quality Certification permit and Final Environmental Impact Report. The permit conditions will become part of the broader Lower Klamath Project License Surrender Order that must be issued by the Federal Energy Regulatory Commission (FERC) before the dams can be decommissioned and removed.

The action comes after an extensive process that began with the KRRC’s application for a Water Quality Certification in 2016. The process involved numerous public meetings in the project area and resulted in adoption of an environmental impact report that considered and responded to more than 2600 comments.

“Decades in the making, this historic and comprehensive project will help restore native fish populations, and improve water quality in the Klamath Basin,” said State Water Resources Control Board Chair E. Joaquin Esquivel. “The strategic removal of aging dams contributes to the restoration of our watersheds and reconnects our landscapes and ecosystems in critical ways. This major restoration project that began in 2008 to remove the dams is now one step closer to becoming a reality.”

As analyzed in the State Water Board’s Environmental Impact Report, long-term water quality benefits of dam removal include a more-natural range of water temperatures, reduced fish disease, and elimination or reduction of the growth of the toxic blue-green algae that threatens the health of humans, animals, and fish. 

The project incorporates portions of the 2010 Klamath Hydroelectric Settlement Agreement, a collaboration that includes the owner of the dams (PacifiCorp),tribes, federal, state and local agencies, nongovernmental organizations, and conservation and fishing groups. PacifiCorp is asking FERC to transfer ownership to the nonprofit KRRC, which was formed in 2016 to carry out the dam-removal project.

The State Water Board supports efforts to improve the Klamath River watershed, but it is not a party to the Klamath Hydroelectric Settlement Agreement. California’s Natural Resources Agency and Department of Fish and Wildlife signed the document as representatives of the state.

In April last year it was announced that construction firm Kiewit Infrastructure West Co was awarded a dam removal design-build contract for the project. In May it was further announced that Knight Piésold would act as lead designer