Expert warns Cloverdale about Potter Valley project risks to Russian River water supply

David Taber, who operates a small water system at Palomino Lakes, told the Cloverdale City Council on Monday that changes planned for the Potter Valley Project could sharply reduce imported water to the Russian River and threaten summer supplies for cities and farms.

Taber, a longtime observer of the Potter Valley Project, said PG&E’s decision to move away from the project and a planned decommissioning of parts of the dam system could end the roughly 115-year pattern of water imports that now deliver on the order of 30,000,000,000 gallons a year into the Russian River watershed. “I’m only gonna tell you the truth,” Taber said at the presentation, adding that the topic is bedeviled by “a spectacular amount of misinformation.”

Why it matters: Cloverdale and neighboring jurisdictions rely on water that is now partly sustained by the Potter Valley diversion. Taber said that regulatory and funding decisions now being negotiated — including an anticipated PG&E draft plan and Federal Energy Regulatory Commission (FERC) review — will determine whether existing tunnel diversions continue and whether replacing the infrastructure is feasible and affordable.

Taber laid out three immediate questions for local officials: where the roughly $50 million capital cost to replace diversion infrastructure would come from; how much delivered water would cost once paid-for supply replaces presently free imports; and how much water will actually be available in the summer months if diversion changes proceed. He estimated current imports at roughly 37,000 acre-feet per year and said ecological needs for the Russian River are around 33,000 acre-feet per year, leaving a narrow margin for human and agricultural use.

“If that tunnel does not continue for one reason or another, this is not a happy place,” Taber said. He said the timeline under discussion points to major regulatory actions and potential implementation around 2028, but that court challenges or other delays are possible.

Taber described technical constraints including sedimentation in Lake Mendocino and the difficulty and cost of dredging; he said sediment removal is technically possible but often treated as hazardous material and therefore expensive to dispose of. He also cautioned that existing water-right holders outside Cloverdale’s municipal boundaries are generally more junior and therefore more likely to face curtailments in drought years.

Questions from council and residents focused on local impacts and legal steps the city should take. Taber urged Cloverdale to engage legal counsel experienced in water-rights law and to coordinate with better-resourced neighbors such as the city of Ukiah, which he said has been active in FERC proceedings. He recommended City attorneys liaise with Ukiah’s legal team (Phil Williams and Sean White were named) and with regional bodies such as Sonoma Water and the emerging IRPA (Russian River project authority) if formed.

Taber also flagged that the future funding model for a replacement diversion entity would likely include per-usage charges; he gave a broad statewide frame that similar changes elsewhere have implied charges in the low hundreds of dollars per acre-foot in some forecasts, though he said “nobody knows exactly” until a plan is formalized.

The presentation concluded with Taber urging deliberation rather than panic and recommending immediate legal engagement so Cloverdale can “have a seat at the table” during negotiations affecting water allocations and costs.

Looking ahead: Taber said PG&E is expected to release a draft plan this month that will trigger formal regulatory negotiations and public comment. He recommended Cloverdale coordinate with Ukiah and other stakeholders and direct city attorneys to review and, if appropriate, participate in FERC filings and related proceedings.