In the Mendocino National Forest, the Potter Valley Project is an audacious example of creative engineering. The project, which is owned by PG&E, stores winter runoff from the upper reaches of the Eel River and diverts the water into the Russian River, where it is used to support people, farming and wineries in Mendocino and Sonoma counties.
The first of two Potter Valley Project dams was built in 1908, when out-of-the-box thinking led engineers to connect the two watersheds by boring a tunnel through a mountain. This water has been used to generate tens of millions of dollars in economic activity for agriculture and has enabled extensive residential development. The impacts of these water diversions on the Eel River ecosystem have been studied, but project impacts have never been mitigated. And Russian River water users currently pay nothing for the water transferred into their system from the Eel River.
The type of imaginative thinking that inspired the Potter Valley Project is the bedrock upon which agricultural prosperity in California is built. And it is precisely this type of inventive solution we should seek to address the Potter Valley Project’s shortcomings through the Federal Energy Regulatory Commission relicensing process that is currently underway.
As with all energy-producing dams in the United States, the Potter Valley Project must undergo periodic review and relicensing by FERC.
This process maintains the safety and integrity of large dams and gives regulators an opportunity to integrate the best available science into dam operations.
Increasingly, the relicensing process is leading to negotiated solutions that protect essential interests — both human and ecosystem-based — and can include changes to how dams are managed, or even structural alterations, up to and including dam removal.
The Eel River was once one of the most prolific producers of wild salmon and steelhead on the West Coast. More than a million fish made their way up river to reproduce in good years, but that number has plummeted.
Only 40 adult steelhead passed through Potter Valley’s Cape Horn Dam this year to spawn.
Recent studies indicate we should not give up on this majestic river. With no fish hatcheries in the system and science-driven opportunities to restore critical fish habitat, the Eel is primed to restore historic abundance and serve as a stronghold for wild fish. Preventing widespread fisheries collapse is critical to preserving the multi-billion commercial and recreational fishing industry. This year’s closure of commercial salmon fishing along the North Coast shows just how much is at stake.
The Potter Valley Project is far from the only threat facing native fish on the Eel River. But it’s clear that there are opportunities to improve flow management and fish passage to historic spawning habitat.
The out-of-the-box thinking that built the Potter Valley Project should be brought to the FERC relicensing process. Are there ways to provide fish passage to the upper Eel watershed but still allow continued diversion to the Russian River?
The FERC relicensing process need not be adversarial. At this stage in the game, it behooves everyone from Potter Valley farmers to fish advocates to Sonoma County water users to come into the relicensing process with an open mind, relying on sound science and with an eye toward a cooperative solution.