To: Board of Supervisors
From: Public Works
Agenda Section: Consent
Vote Requirement: Majority
SUBJECT:
title
Authorization for the Public Works Deputy-Director for Environmental Services to Make a Recommendation to the Eel-Russian Project Authority Regarding Diversion Facility Modifications at Cape Horn Dam
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RECOMMENDATION(S):
Recommendation
That the Board of Supervisors:
1. Authorize the Public Works Deputy-Director for Environmental Services to make a recommendation to the Eel-Russian Project Authority regarding the preferred design alternative for diversion facility modifications at Cape Horn Dam.
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SOURCE OF FUNDING:
General Fund (1100251)
DISCUSSION:
On March 19, 2024, the Eel-Russian Project Authority (“ERPA”) is scheduled to select a preferred design alternative for diversion facility modifications at Cape Horn Dam on the Eel River. ERPA is a newly formed joint-powers authority comprised of the County of Sonoma, Sonoma County Water Agency, and Mendocino County Inland Water and Power Commission. These modifications are envisioned to be implemented in conjunction with Pacific Gas and Electric’s (“PG&E’s) decommissioning of the Potter Valley Hydroelectric Project. The selected alternative would be carried forward for further design development and environmental review. This decision by ERPA to select a preferred alternative would be for the purpose of further feasibility and planning studies to inform possible future action. The timeline for alternative selection is driven by PG&E’s schedule for preparing their revised license surrender application and decommissioning plan which will be released in June 2024.
In 2023, Sonoma County Water Agency convened a technical advisory group to review the preliminary engineering for two (2) potential water diversion facility alternatives based on specified evaluation criteria. A primary goal is to improve fish passage and habitat on the Eel River sufficient to support recovery of naturally reproducing, self-sustaining and harvestable native anadromous fish populations, including migratory access upstream and downstream at Cape Horn Dam. The first alternative would include substantial removal of Cape Horn Dam to restore a natural channel and construction of a new pump station near the dam location. The second alternative would lower the concrete portion of Cape Horn Dam to a specified elevation and construct a stabilized channel (also known as a “roughened channel” or “nature-like fishway”) that would allow water diversion without pumps. The technical advisory group is scheduled to provide its recommendation for the preferred alternative on March 13, 2024. This group includes representatives from National Marine Fisheries Service and California Department of Fish and Wildlife.
Humboldt County (represented by Public Works and County Counsel) has been meeting regularly since September 2023 with a group of stakeholders convened by the California Department of Fish and Wildlife and the Round Valley Indian Tribes. This group includes Sonoma County Water Agency, Mendocino County Inland Water and Power Commission, California Trout, and Trout Unlimited. This group is scheduled to provide recommendations for the preferred alternative to ERPA on March 15, 2024.
Staff recommend that the Humboldt County Board of Supervisors authorize the Public Works Deputy-Director for Environmental Services to make a recommendation to ERPA regarding the preferred design alternative for diversion facility modifications at Cape Horn Dam. Public Works would review the recommendation of the technical advisory group and consult with the Board’s Eel-Russian River ad hoc committee prior to making a recommendation to ERPA. If approved, this action would enable staff to advocate for the interests of Humboldt County and the protection of the Eel River in ongoing regional discussions.
Making a recommendation on the preferred alternative for diversion facility modifications at Cape Horn Dam is consistent with Humboldt County’s conditional support for the proposal for limited winter-time water diversions in conjunction with PG&E’s decommissioning of the Potter Valley Hydroelectric Project and creation of an Eel River Restoration Fund. A technical study commissioned by Round Valley Indian Tribes is currently in progress to develop a proposal for limitations and constraints on water diversions to ensure that flows in the Eel River support robust salmonid populations. Staff will bring any proposed formal agreements regarding the decommissioning of the Potter Valley Hydroelectric Project or development of a modified water diversion facility to the Board for review and approval.
FINANCIAL IMPACT:
The proposed action will not affect ongoing efforts by staff and, therefore, will have no effect on the General Fund.
STAFFING IMPACT:
Existing staffing would implement the proposed action. There is no additional staffing impact.
STRATEGIC FRAMEWORK:
This action supports the following areas of your Board’s Strategic Framework.
Core Roles: Create opportunities for improved safety and health
New Initiatives: Advance local interests in natural resource discussions
Strategic Plan: 2.2 - Improve trails, rivers, and parks infrastructure
OTHER AGENCY INVOLVEMENT:
California Department of Fish and Wildlife, National Marine Fisheries Service, Sonoma County Water Agency, Mendocino County Inland Water and Power Commission
ALTERNATIVES TO STAFF RECOMMENDATIONS:
The Board could choose not to authorize the Public Works Deputy-Director for Environmental Services to make a recommendation to ERPA regarding the preferred design alternative for diversion facility modifications at Cape Horn Dam. This alternative is not recommended because it would reduce Humboldt County’s influence in the ongoing regional discussions regarding the future of the Potter Valley Hydroelectric Project and a potential future water diversion facility.
ATTACHMENTS:
N/A
PREVIOUS ACTION/REFERRAL:
Board Order No.: J-3
Meeting of: January 30, 2024
File No.: 24-148