OAKLAND >> Pacific Gas and Electric Company presented a podcast on August 11, to update the public regarding its intention to surrender its license and eventual dismantling of the Scott Dam and the Cape Horn Dam in Mendocino County then cease hydroelectrical power generation.
The Eel-Russian Project Authority is a joint powers authority formed by a joint exercise of powers agreement between the County of Sonoma, Sonoma County Water Agency (Sonoma Water) and the Mendocino County Inland Water and Power Commission (IWPC).and Round Valley Indian Tribes, whom all have a seat on the five-member Board of Directors, which is comprised of two representatives from IWPC, one from Sonoma Water, one from the County of Sonoma, and one from Round Valley Indian Tribes. The five-member Board of Directors: Sonoma Water, Chair David Rabbitt: County of Sonoma: James Gore, Mendocino County Inland Water & Power Commission : Vice Chair Janet Pauli, Mendocino County Inland Water & Power Commission: Madeline Cline, Round Valley Indian Tribes: James Russ.
The Eel-Russian Project Authority is negotiating with PG&E as the utility moves ahead with plans to surrender operations of the Potter Valley Hydroelectric Project and to decommission the Scott and Cape Horn dams on the Eel River. The Eel-Russian Project Authority will also have the legal capacity to own, construct and operate a new water diversion facility near the Cape Horn Dam.
On July 25, 2025, PG&E filed its Surrender Application and Decommissioning Plan for the Potter Valley Project with the Federal Energy Regulatory Commission (FERC). PG&E previously made available two drafts for public comment. FERC will now review the application and in the process will seek input from all interested parties through its open public comment period. In addition, the public will have opportunities to participate in FERC’s National Environmental Policy Act (NEPA) review and the California State Water Resources Control Board’s (SWRCB) California Environmental Quality Act (CEQA) review through their public comment processes, throughout summer.
With the application filed, PG&E will begin the process of developing management and construction plans that will further detail the decommissioning process and aspects of the project. Dave Gabbard, vice president of power generation for PG&E said the July 25 filing “marks the next step of a thoughtful and transparent decommissioning journey for the Potter Valley Project—but it does not change our operational responsibilities or obligations.”
The FERC submittal includes a request to allow the Eel-Russian Project Authority (ERPA) to construct the New Eel-Russian Facility (NERF) at the current location of Cape Horn Dam. The NERF will provide diversion flows from the Eel River to the Russian River watershed after PG&E’s removal of Cape Horn Dam and Scott Dam. The removal of the two PG&E dams will allow fish to access habitat in the Upper Eel River watershed.
Dave Manning, is the executive director of the Eel-Russian River project. He noted the Coyote Valley Dam (though not slated for removal) is the third critical dam in sustaining plentiful water in the North Shore. It was created in the 1950s by the Army Corps of Engineers.
The Sonoma County Water Agency and Mendocino County Local Power Company, along with the other three partners mentioned above, are some of the local sponsors of the planned continuing water diversion project to proceed while and after the dam removals pointed out Manning. “Water that results from the historic merger of the Eel-Russian River merger, is critical to reliability of water in the Coyote Valley Reservoir,” he said. “It is the top end of the system of the Russian River that we manage for all the beneficiaries of the Russian River aggregate,” he said.
This would include the Lake County municipalities, commercial agriculture, recreation and sustainable environment initiatives. “The historic connection of the Eel-Russian River link via the Potter Valley Project is so strong, the hydraulic emissions whether a wet or dry year, has been historically set by inflow to Lake Pillsbury,” he said. “If you look at the time Lake Pillsbury, was created, 1922 to 1925; the Potter Valley Project operates on average at 150,000-acre feet of water was diverted from the Eel into the Russian River, due to changes in environmental regulations; (resulting) in more protection and more fish in the Eel River.
Professional opinion over the prior decades is the diversion volume has decreased by about half, 60,000 acre feet. And added to equipment failures, average yields are now about 30,000-acre feet per year. Diversion in the face of the decommissioning and surrender process prompted formation of the ‘two-based partnership’ to try to yield two equal goals. One is to improve fish migration habitat on the Eel with the objective of sustaining fish populations; and the second is to continue diversions from the Eel to the Russian River, achieved through the existing tunnel that’s part of the Potter Valley Project that supports all the beneficial uses of the water in the Russian River basin, thanks to the efforts of the Eel-Russian Authority.
Here’s what PG&E’s vision; following the removal of the Cape Horn Dam. The center spillway portion of the dam has been removed and in its place on the river is a pumphouse so water can be pumped without elevation from the dam upstream to the existing tunnel, and with that flow of gravity down the to the Russian River. A retaining wall protects the conduit to the diversion tunnel. And when most of the dam is removed, there’s is nothing competing with the fish, either up or downstream, Manning pointed out.
The one limitation on the amount of water diverted is the ability of how much storage Lake Mendocino can handle. The water flows from the tunnel through the east branch of the Russian River into Lake Mendocino noted Manning but there’s times when water in Lake Mendocino’s flood pools are at capacity and the project could not work as intended so, water would not be diverted. Yet there’s times when there’s space in Lake Mendocino to capture it. and that water is stored throughout the summer.
So, in order for this new Eel-Russian facility to be constructed, there must be a California Environmental Quality Act analysis completed. “We’re hoping this work begins this fall,” Manning said. “We’ll work closely with the Eel-Russian Authority partners, as well as the California Water Control Board. At PG&E we expect about 24 months (required) once the work begins. We are preparing to have the new facility constructed and permitted (by FERC) as the dam decommission proceeds.”
