Board approves water diversion agreement to accompany Potter Valley dam decommissioning

The Humboldt County Board of Supervisors voted 5-0 to approve a proposed water diversion agreement related to Pacific Gas and Electric Co.'s decommissioning of the Potter Valley Hydroelectric Project and the construction and operation of a new Eel–Russian diversion facility.

The agreement, described to the board by Hank Seaman, Public Works deputy director, sets coequal goals of improving conditions on the Eel River to support naturally reproducing, self-sustaining fish populations and maintaining continued, constrained diversions to support water supply reliability and water quality in the Russian River basin. “Pacific Gas and Electric is preparing to decommission the Potter Valley hydroelectric project, which is located on the Upper Eel River,” Seaman said during the staff presentation.

County staff told supervisors the agreement was negotiated by a coalition of public agencies, tribes and conservation organizations and is intended to be offered to PG&E as part of the company’s license-surrender and decommissioning process with the Federal Energy Regulatory Commission (FERC). The document would support PG&E’s removal of Scott and Cape Horn dams and the transfer of necessary lands and water-right interests to entities that will implement a “run-of-river” diversion (no new storage dams).

Key provisions and why they matter

- Limits on diversion and river protections: The agreement sets seasonal minimum flows (“floors”) and maximum percent-of-flow diversion limits intended to protect Chinook, coho, steelhead and lamprey as well as broader ecosystem functions. Staff summarized the seasonal floors as roughly 300 cubic feet per second (cfs) in fall, 250 cfs in winter, 125 cfs in spring and 35 cfs in summer, with maximum diversion rates ranging from 20% to 30% depending on season. Staff presented model runs showing modest average reductions in downstream flows at Scotia (on the Eel River) in the range of roughly 0.2% to 1.4% under the diversion rules used in the analysis.

- Institutional structure: The agreement anticipates creation of a project authority to design, construct and operate the new diversion facility and calls for transfer of PG&E’s project lands and certain water rights. The water rights would be transferred to the Round Valley Indian Tribes, which would lease use of the rights to the project authority under the terms described in the agreement.

- Payments and restoration funding: The agreement requires recurring payments from the project authority to the Round Valley Indian Tribes — a $1,000,000-per-year use charge plus a minimum $750,000 annual restoration payment that would be routed to an Eel River restoration fund administered by a new nonprofit (the “Eel River Restoration Corporation”). Payments include CPI adjustments and are structured to increase if public funding for construction exceeds certain thresholds; if the agreement is renewed after an initial 30-year term, the base payments would increase by a minimum of 15%.

- Monitoring and adaptive management: The agreement establishes monitoring, performance metrics and an adaptive-management process to alter diversion schedules if monitoring shows the river is not meeting agreed performance objectives. Staff emphasized that the diversion rules were developed by technical experts and modeled with historical hydrographs.

- Term and renewal: The agreement carries an initial 30-year term with a conditional 20-year renewal if specified criteria are met, including proof of funding for the restoration fund, compliance with diversion and payment provisions, and a demonstration that continued diversions will not impair recovery of Eel River fisheries.

Who supported and who spoke

Trout Unlimited, California Trout and Friends of the Eel River — parties to or aligned with the negotiated agreement — addressed the board in support. Brian Johnson of Trout Unlimited said TU would sign the agreement and placed value on having a “seat at the table” rather than pursuing adversarial litigation that could delay dam removal. Charlie Schneider of California Trout described technical engagement to refine facility design and flows. Alicia Hayman of Friends of the Eel River said she was not a signatory to the agreement but supported its outcome as a practical way to secure support for timely dam removal and to open habitat behind Scott Dam.

Supervisor comments and board action

Supervisors who spoke during the item emphasized the county’s long-standing preference for keeping water in the Eel but described the agreement as the most practicable path toward dam removal and new, enforceable protections for the river and tribes. After public comment, Supervisor Bond moved to approve staff’s recommendation; the motion carried unanimously (5-0).

What the county said it will do next

County staff asked for authority to continue working with the parties and PG&E through the FERC license-surrender and decommissioning process, to return with an MOU establishing the restoration corporation, and to approve Humboldt County public statements or joint letters about the agreement as negotiations proceed.

Ending

County staff and conservation groups described the agreement as a negotiated compromise intended to expedite dam removal, provide dedicated restoration funding, and limit diversions by season and flow. The board’s approval makes Humboldt County a formal party to the multiagency proposal to PG&E; the agreement still requires additional steps, including PG&E’s disposition of property and water rights and subsequent regulatory approvals at the federal and state level.