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Groups sue PG&E over endangered species; both dams to come out unless entity steps up

A dam with a sluice.
Cape Horn Dam in Potter Valley.

Lawsuit, decommissioning, and future of Potter Valley hydro and possible diversion come before diverse group of interests.

A coalition of environmental advocates and commercial fishing groups has made good on its threat to sue PG&E over its management of the Potter Valley hydroelectric project. PG&E is scheduled to present a plan to decommission the project by the beginning of 2025. At a meeting last month about Scott Dam and Lake Pillsbury, PG&E licensing experts said they plan to remove both the dams, but did not provide a timeline.

Today, a planning group for a multi-county body called the Russian River Water Forum gathered in Ukiah to discuss members’ interests in the decommissioning process. According to its website, “The Water Forum seeks to identify water-supply resiliency solutions that respond to PG&E’s planned decommissioning of the Potter Valley Project while protecting Tribal interests and supporting the stewardship of fisheries, water quality, and recreation in the Russian River and Eel River basins.” The Forum was started by Sonoma Water and is funded by the California Department of Water Resources.

The planning group consists of five agriculture or resource conservation district representatives from Mendocino and Sonoma counties, one recreational rep from Sonoma county, one speaker for commercial fisheries, one county official each from Mendocino, Lake, Sonoma and Humboldt counties, four environmental reps, ten water suppliers, and tribal government officials from Round Valley, the Wiyot tribe, Potter Valley, Pinoleville, Yokayo, and the Lytton Band of Pomo Indians.

The environmentalists and fishermen announced their intent to sue in federal court under the Endangered Species Act last year. They contend the project causes unauthorized take of endangered salmonids by exposing them to easy predation at Cape Horn Dam and depriving them of habitat above Scott Dam. The suit was filed yesterday in the Eureka-McKinleyville Division of the United States District Court in northern California.

Last year, when the project’s twenty-year license expired, the National Marine Fisheries Service recommended that PG&E implement a number of interim protective measures while the project is still in place. In a letter to the Federal Energy Regulatory Commission last week, the Service reiterated its recommendation and requested more information to initiate consultation under the Endangered Species Act. Many of the recommended interim protective measures are designed to keep water cool enough for salmonids below Scott Dam, which is another sticking point in the lawsuit. The Service also wrote that the Cape Horn Dam fish ladder is “likely not in compliance” with its fish passage guidelines. They requested a comprehensive set of evaluations of the dam, including predation risk to juvenile and adult salmon, and the “safe, timely, and effective downstream passage for adult steelhead.”

Cape Horn Dam, which impounds van Arsdale reservoir at a diversion tunnel that sends water from the Eel River into the East Branch of the Russian River, was built in 1908. It quickly filled with sediment, leading to the construction of Scott Dam and the creation of Lake Pillsbury in 1922. Typically, the radial gates on Scott Dam would be closed in the first week of April, but due to seismic safety concerns, the gates remain open. PG&E estimates this will lead to a 25% reduction in lake levels but also take pressure off the dam, reducing the risk of damage in the event of an earthquake.

At a virtual town hall on the future of Scott Dam and Lake Pillsbury last month, Dave Ritzman, PG&E’s chief dam safety engineer, said that initial analyses using improved seismology show that the probability of a major earthquake on the nearby Bartlett Fault is once every 900 years, which is more frequent than previously understood. He said the Division of Safety of Dams, or DSOD, agreed with the findings of PG&E’s engineers, and the decision to reduce lake levels by leaving the gates open.

“While the risk is low, the restriction aligns with PG&E’s commitment to public safety,” he said. “We submitted our report of the seismic stability analyses and the proposed reservoir restriction to FERC (Federal Energy Regulatory Committee) and DSOD in mid-March. DSOD responded to us a couple of weeks ago with their concurrence with the proposed restriction.”

Tony Gigliotti, PG&E’s senior licensing project manager, explained what the company means by decommissioning.

“When we say decommissioning in this case, both dams will be removed as part of that, unless somebody comes forward with a proposal that PG&E looks at and accepts,” he said. “We need to ensure they can operate the dams after we give up ownership. In terms of timelines for the surrender application, there will be an initial draft November, 2023. A second draft, also available for public review, May, 2024, and then the final application will be filed with FERC in January, 2025.”

Janet Walther, PG&E’s senior manager of hydro licensing, took another question about the timeline and gave a heads-up to entities that might be in the market for a hydropower facility.

“When PG&E submits our final surrender application to FERC, that would be the point of no return,” in terms of decommissioning, she said. “And really, the draft. We are looking to know, sooner than later, if there’s an entity interested in taking over the dam because that will change our surrender application and what we put in that surrender application. So I think we are looking and would like to see some initial proposals later this year, if there is interest. And we are talking with folks, as we have been since 2016, about potential interest in future ownership of Scott, and or Cape Horn Dam."

Walther did not have a surprise answer to a question about who would pay to decommission the project. “In our general rate case, we have been developing a decommissioning fund for our hydro facilities, and that is borne by customers,” she said.

Local News
Sarah Reith came to Mendocino County in 2008 and worked as a reporter and freelancer, joining KZYX as a community news reporter in 2017. She became the KZYX News Director in March, 2023.