For over a century, the Potter Valley Project has delivered Eel River water through the mountains to the Russian River basin, providing reliable irrigation, frost protection, and municipal supply to thousands of residents and farmers in Mendocino, Sonoma, and Lake counties. Today, that century-old system faces decommissioning, with far-reaching consequences for local agriculture and rural livelihoods.

The project, originally built in 1908 and expanded by PG&E, diverts water through a tunnel from the Eel River at Cape Horn Dam to a powerhouse in Potter Valley, then into the East Fork Russian River. At its peak it generated hydroelectric power and supported vineyards, orchards, and pear growers who rely on predictable spring and summer flows.

The Path to Decommissioning

PG&E announced in 2019 its intent to surrender the federal license, citing high maintenance costs and seismic risks at Scott Dam. Since then, a coalition of environmental groups, Native tribes, and fisheries advocates has pushed for full removal of both Scott Dam and Cape Horn Dam to restore natural flows to the Eel River and aid salmon recovery. In 2024, the Federal Energy Regulatory Commission approved a surrender plan that would remove Scott Dam while leaving Cape Horn Dam in place for a potential reduced diversion.

"The debate is not simply environment versus agriculture; it is about who controls critical resources and whether decisions made in Sacramento and Washington reflect the needs of rural communities."

A new entity—the Two-Basin Partnership (comprising Humboldt County, Sonoma Water, Mendocino Russian River Flood Control District, and others)—is working to create a regionally-managed, minimally diverted system focused on meeting downstream Russian River needs without hydroelectric generation. Funding remains uncertain, and timelines have repeatedly slipped.

Stakes for Local Residents

For Mendocino County residents, especially in Potter Valley and the upper Russian River communities, the stakes are high. Reduced or eliminated diversions could mean less water for irrigation and frost protection at critical times, higher pumping costs from the Russian River or Lake Mendocino, and potential impacts on property values and agricultural viability. Local growers have already voiced concerns that state-driven restoration priorities overlook the human and economic costs in the Russian River basin.

The debate is not simply environment versus agriculture; it is about who controls critical resources and whether decisions made in Sacramento and Washington reflect the needs of rural communities. Residents deserve transparent planning, firm commitments to maintain minimum flows, and a voice equal to that of distant stakeholders.

The Mendocino Patriot will continue tracking developments and amplifying local perspectives on this defining water issue.