Lake Mendocino July 31, 2021

Lake Mendocino is pictured on July 31, 2021. 

The long-term picture for reliable water flows in the Russian River, above Healdsburg to Mendocino County, will remain uncertain for at least two more years, if not longer. The hold up stems from ongoing studies and multi-agency negotiations over the future of the Scott Dam on the Eel River and the century-old Potter Valley Project (PVP) that diverts Eel River water into the Russian River and Lake Mendocino.

On Sept. 2, the five-member Two-Basin Partnership asked the Federal Energy Regulatory Commission (FERC) for a one-year abeyance to continue evaluations of a proposed takeover of the PVP from Pacific Gas and Electric (PG&E) which has announced it will not renew its FERC permit after 2022. The Two-Basin Partnership is seeking removal of the Scott Dam but continued Eel River diversions into the East Fork of the Russian River. The proposal would add 288 river miles of access to salmon and steelhead while assuring an annual diversion of 62,500 acre/feet of water.

The partnership is citing a shortage of funds to operate the PVP and said last week “we have made substantial efforts but have not yet secured public and philanthropic funds for that work.” In May, PG&E declined to fund the project and by statute the utility is barred from seeking a new license.

Although the request to FERC does not directly involved the current drought, the partnership request did report “the upper Russian River basin is at a low point unprecedented in living memory. Lake Mendocino may run dry for the first time since its construction in 1958.”

The delay request was signed by Grant Davis, Sonoma Water; Janet Pauli, Mendocino County Inland Water and Power Commission; James Russ, Round Valley Indian Tribe; Curtis Knight, California Trout; and Hank Seemann, Humboldt County Public Works.

The Potter Valley Project consists of two dams, a small hydro power plant and a mile-long tunnel between the Eel and Russian rivers. The uppermost dam, Scott Dam, creates Lake Pillsbury, a 76,876 acre/feet reservoir. Removing the dam would open fish habitat but eliminate a popular recreational area. The much smaller Van Arsdale Reservoir is formed by the Cape Horn Dam, which is the outlet for the water diversion tunnel.

Lake Mendocino is at historic low levels even with the Eel River diversion, which has been curtailed under “critical year” state Water Resources Control Board rulings. Potter, Redwood and Alexander valley farmers, ranchers and vineyard operations rely heavily on the Eel water diversion. Also, Cloverdale and Healdsburg municipal wells are recharged by the Lake Mendocino releases.

Currently, all of these agricultural users are under state-mandate curtailments prohibiting pumping any water from the river. Cloverdale municipal water customers are under a 35% water curtailment edict and Healdsburg users are under the county’s toughest restricts at 40% cutbacks.

Long-term weather forecasts are not good. Below average rainfall is being predicted for the coming winter season and all local water suppliers, led by Sonoma Water, expect to keep water conservation measures in place into at least mid-2022, if not longer.

The biggest question about the future of the PVP would arise if the Two-Basin Partnership fails to implement a takeover plan before the PG&E FERC permits expire. A well-timed takeover would require PG&E and its ratepayers to pay for some of the revised project work and dam removal. But if the FERC license lapses it is not cleat the project would be granted a new water diversion permit form the State Water Resources Control Board.

“In all of these respects, time is of the essence to resolve the future of this project,” the Sept. 2 abeyance request stated.

(1) comment


Great work by the author for making a complex topic clear for the rest of us.

It's important to remember there is no law requiring rainfall as we knew it.

Where is our great single-party state government on the topic of constructing more water retention systems? Nowhere to be found.

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