On January 31, PG&E released its draft license surrender application and decommissioning plan for the Potter Valley Hydroelectric Project in Mendocino and Lake counties. In the draft plan, PG&E proposes to remove Cape Horn Dam and the Scott Dam in Lake and Mendocino counties. Both dams are located on the Eel River.
The dams block salmon and steelhead from historic spawning grounds during their annual returns from the Pacific Ocean. CSPA strongly supports the removal of the dams.
The facility has become unprofitable to maintain and operate. The infrastructure is over 100 years old and is in constant need of expensive repairs. In addition, Scott Dam may not be able to survive an earthquake. In 2023, PG&E started limiting the amount of water stored behind Scott Dam to reduce the risk of catastrophic dam failure.
Scott Dam, photo taken in 1967. Image: California Department of Water Resources
An erosion area on the right embankment of Cape Horn Dam, photo taken in 1965.
Image: D. L. Christensen, California Department of Water Resources
PG&E has proposed a “rapid removal” of the dams that is set to unfold over a two-year period. Expediting the dam removals requires the approval of the Federal Energy Regulatory Commission (FERC).
A public comment period on the draft plan ended on March 3. PG&E will consider the comments individuals and organizations submitted on the draft plan in preparing its final license surrender application, due to FERC on July 29.
The expected removal has led a coalition of entities, including Mendocino and Sonoma counties and the Round Valley Indian Tribes, to design a “Two-Basin Solution.” This would involve a new wintertime diversion of water to the Russian River. This new system would meet some of the water demands currently filled by the Potter Valley Project.
Work on the new diversion would not involve PG&E. Funding for the project is expected to come from the Inflation Reduction Act. On January 20, U.S. representative Jared Huffman (D-CA) announced the Round Valley Indian Tribes and the Sonoma County Water Agency were awarded $15 million by the U.S. Bureau of Reclamation toward the implementation of the Two-Basin Solution.
Before the Cape Horn and Scott Dams were in operation, the Eel River featured some of the largest salmon and steelhead runs in California. Dam removal will restore access to up to over a hundred river miles of spawning and rearing habitat for these species. The potential removals present an exciting opportunity to restore the once-prolific salmon and steelhead populations in the mainstem Eel River.
A mature Coho salmon returns upriver to spawn. Image: K. King, U.S. Fish & Wildlife Service