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Russian River flows at risk: New studies show potential path forward for Potter Valley project

A group of studies released last month paint a clearer picture of how Sonoma and Mendocino counties can meet future water needs while reducing environmental impacts in the face of a decision by PG&E to cease operation of an aging hydroelectric power project.

The Potter Valley Project (PVP) is located approximately 15 miles north of the City of Ukiah on the Eel River. The Project’s facilities include two dams, a diversion tunnel and a hydroelectric plant located in Potter Valley in the headwaters of the Russian River. The 100-year-old project produces little electricity by modern standards and is a net money loser, but Sonoma and Mendocino County water users have grown accustomed to the water diverted by the Project which flows from the Eel River into the Russian River watershed where it is stored in Lake Mendocino – ultimately flowing down the Russian River where it benefits agricultural interests and residents.

This arrangement was put in jeopardy when PG&E announced in 2019 that it would not seek to renew its federal license to operate the Project, which expires in April 2022. In recent weeks, PG&E also notified the public that the Project’s powerhouse had suffered a transformer failure, which eliminated its ability to generate electricity and reduced water diversions into the Russian River. Given PG&E’s goal to dispense with the Project, it is unlikely the powerhouse will be repaired or that the Project will ever function as it once did.

In response to PG&E’s decision to divest from the Project, a diverse group of stakeholders called the Two-Basin Partnership was formed to develop a plan to take over and modify the Project in a way that reflects regional needs and priorities in both basins. Among these priorities are fisheries recovery in the Eel River – one of the few major rivers left in California that has the potential to support abundant, self-sustaining wild populations of salmon and steelhead – and water supply reliability for Russian River water users. The Partnership’s proposed plan included the removal of Scott Dam, restoration of the drained Lake Pillsbury footprint and modifications or the replacement of Cape Horn Dam to maintain a diversion.

However, the Partnership has recently acknowledged that their efforts to raise sufficient funds to acquire the Project will likely fail. If no party is able to take over the Potter Valley Project from PG&E, the utility will be required to submit a plan to federal regulators to decommission the Project once the license expires. PG&E will remain responsible for the impacts of the Project and the cost of decommissioning until federal regulators determine the decommissioning process is complete.

Though it is unknown what PG&E’s decommissioning plan will entail, it would likely mean an end to the water diversion from the Eel to the Russian because PG&E’s legal right to divert water is currently tied to the Public Utilities Commission (PUC) license for hydropower generation. The Partnership and other stakeholders, including Congressman Jared Huffman, are still seeking ways to meet water needs in both basins. Two studies recently prepared for the Partnership evaluate a so-called “run of the river” plan that would remove both Scott Dam and Cape Horn Dam while maintaining winter-time water diversions into Lake Mendocino when Eel River flows are abundant, a proven strategy to limit water use impacts on the environment. Congressman Huffman has suggested that a group of stakeholders working with PG&E during the decommissioning process to take over their water rights and the diversion tunnel might be an easier path to solving this regional problem.

The studies showed that dam removal costs are projected to be lower than originally anticipated and that multiple options for continued diversion appear to be financially and technically feasible. While a path forward remains unclear, these studies are good news for stakeholders in both the Eel and Russian River basins. They show there are practical solutions to reducing impacts to Eel River fisheries and ecosystems while maintaining water diversions into the Russian River, something stakeholders in both basins have so far agreed on.

PG&E’s license to operate the Potter Valley Project expires in April of 2022. For more information until then:

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