MENDOCINO CO., 8/18/26 — One of the concerns about taking out the two dams of the Potter Valley Project — Scott and Cape Horn — is the loss of water downstream for agriculture, recreation and drinking water. This month Mendocino County officials shared preliminary studies of what would replace the dams: the New Eel-Russian Facility.
The news is promising: the Eel River project on the drawing board could keep about as much water flowing to the Russian River each year as today’s system does, with more of it arriving in the wet winter months. The facility would replace the Potter Valley Project, a century-old set of dams and a tunnel that sends Eel River water over the hills into the Russian River watershed. PG&E is giving up that project and plans to tear down Scott Dam and Cape Horn Dam. The new facility would pump water from the Eel during the rainy season into the same tunnel that’s used now.
That water matters far downstream. It fills Lake Mendocino, which supplies farms in the Ukiah Valley and drinking water for hundreds of thousands of people in Mendocino, Sonoma and Marin counties.
The new models studied by officials were built by Sonoma Water. In a press release last week, the Mendocino County Inland Water and Power Commission said the analysis looked at how much water the new facility could have moved over the past 13 years. The answer, it said, was that water would have been available to move in every single year — even in dry ones.
The amounts swung widely by year. In the severe drought of 2021, the new facility would have moved about 18,000 acre-feet. In the wet year of 2017, it would have moved about 86,000 acre-feet. An acre-foot is about 326,000 gallons — enough to cover an acre of land 1 foot deep.
The modeling also checked the most recent 21 months, from October 2024 through June 2026. Over that stretch, the new facility would have moved about 52,000 acre-feet. The old system actually moved about 56,000 acre-feet in the same period. In other words, the new setup would have come close to matching what the current one already does.
More storage is the answer
There’s a catch, though. Over a full year, the new facility would move about the same amount of water as the current project does now. What changes is the timing. More water would arrive in the wet winter months — and that’s often when Lake Mendocino and other storage are already full. Water that shows up when there’s nowhere to put it can’t be used.
That’s why the commission says the region needs more places to store water. In normal, non-drought years, it found, an average of about 40,000 acre-feet of extra water could be put to use each year if there were room to hold it. Ideas on the table include raising Coyote Valley Dam, building off-channel storage and recharging groundwater.
“The modeling confirms that the New Eel-Russian Facility can work, and that water will truly be available for diversion, every year, including during drought years,” Dave Koball, an alternate commissioner for the Inland Water and Power Commission, said in a statement. “It also reinforces why diversion and storage must be pursued together. Additional storage will allow us to capture more water when it is available and preserve it for the farms, businesses and communities that need it later in the year.”
The New Eel-Russian Facility is being developed by the Eel-Russian Project Authority, a partnership of Sonoma Water, Sonoma County, the Inland Water and Power Commission and the Round Valley Indian Tribes. A water-sharing agreement signed in July 2025 also includes fish and wildlife agencies, Humboldt County and conservation groups, and it sets rules meant to protect the Eel River and its salmon while allowing the wet-season diversions.
The models are still preliminary, officials said. PG&E filed its final plan to surrender the Potter Valley Project with federal regulators in July 2025, and the review is ongoing. Federal officials are taking public comment on the plan through Sept. 18.
Great. The next question is how much does it cost and who is footing the bill for this?
That’s a great question because right now it’s PG&E customers which is a pretty sweet deal if you’re a farmer in Potter Valley. It’s really important that if this moves forward those that use the most water pay the most for building this thing, and urban customers don’t get stuck with higher rates so the whine industry can profit.
Conveniently leaves out the fact that The Round Valley Tribes will charge $2M annually just for the permit to divert water.
#savelakepillsbury
Also leaves out the fact that PG&E has been paying for the dams and they don’t want to anymore. Bootstraps anyone?
No matter what changes occur, water will still be in short supply. And that’s going to affect a lot of people, let alone agri-business, so speak plainly that we might comprehend the bigger picture.
It’s great to see reporting on this. I have long suspected that the Save Lake Pillsbury crowd has really done our region a real disservice by pretending that spending hundreds of millions to fix up old dams is the only path to water security. It’s clear they really only care about their lake houses and will say almost anything to keep them. I am glad our local water engineers are sharp enough to come up with an affordable solution that will actually result in long-term water security and its great to see the numbers. Placing bets on 100-year-old dams has always seemed risky to me.
It’s interesting that these water agreements were made nearly 120 years ago when it was a different world. Times have changed and Mendocino county is held to an agreement where it ships its water and has to ask permission from to Sonoma county to hold some back in Lake Mendocino during dry times. Typical of humanity, where the best and often only planning is built around money and resource extraction
Get your grape-growin’ filthy hands off our water~*
*Humboldt County
Grappling grapers are ready to
R—–p us of every drop of water they can.. Just how much dose the governor’s (Newsum’s) grape vineyards need for his wine/restraunts buzzzness require? Only his blind trust lawyers know. Better Less water for cash cropping and more for the food we could be growing locally, 🥺.
FROM A WATER DRINKER
It is funny grapes come up! Alit of grape growers are pulling vines as wine consumption declines. There is a lot of food production that will be at stake if we don’t get the water figured out! I laugh at those who think it is only people with lake houses… pg& e is charging us for the bill to tear it down and round valley gets 2 million a year even if they deco not to let water divert! Because they can. Lake Mendocino helps everyone. It will take years to build water storage but no one is focusing on that. So sad. Potter Valley farmers pay the rate that is asked. This is so much bigger than we think. Why pit each other against rural and urban. Farms feed people water is essential to all. PG&E is a joke .
There are voices for more water storage. The angst is directed at who pays for this proposed water infrastructure and how it is used. Many folks have no appetite to subsidize the AG community. The benefits of AG don’t justify the cost simply put. PG&E came to the same conclusions after they rebuilt large portions of Sonoma and Mendocino Counties. Farms feed people is merely an empty platitude at this point.
Small farms aren’t subsidized. I know you go to the store and buy food! It may be true for big agricultural but all these farm to table farmers and local farms are important. Where your food comes from is important. California grows much of the food that feeds people all over! Build more water storage. But stop whining about farmers taking your money or you helping them. What Economy is next to disappear in Mendocino?
The mendo farming community whether they are big or small take more than they put out especially given the huge cost of the infrastructure maintaining it. Even if you remove the “big” Ag farms, the small and mid size farms are maintaining tax breaks and benefit from subsidy programs from the feds and state whether they grow food or not. All of the “food” producing farms in Mendo couldn’t feed its own community. The vast majority of the produce in the county is imported in from the central valley or Mexico. The vast majority of this eel river water use to go to mono crops like grapes and cannabis. The only ones whining are the farmers who have to pay the real cost for their water.
Urbanist you are truly lame! I know you go to Safeway but there are lots of farms that produce here! I buy locally and do fine! The cannabis industry is not what it was so don’t blame theme one day you may turn on your tap and realize it is a bigger issue then you realize. Must be nice knowing everything. It is not just the farmer bubs… water is precious to all the whole web of life. We need storage. One day instead of oil people will be fighting for water to survive. But enjoy that city water!
Not all storage is created equal though. Small farmers are often left out of these decisions while big farmers have a seat at the table. Surface storage isn’t really about storage, it’s about control, and importantly, who has it. The wine industry may be in the dumpster, but its deep pockets are what is driving this because they want control of this water for themselves.
Bottom line…
PG&E has not met their responsibilities and requirements of maintaining the dams and properly managing the silt behind the dam. All of these Deficiencies are and always have been PG&E responsibilities as per their contract agreement.
Just because the equipment failed and they chose not to replace the parts required, it does not eliminate them from the responsibility of these repairs and maintenance. Deferred maintenance is not a choice that PG&E has the power to make.
Everyone is talking about how old the dam is and how much work it needs. PG&E needs to pay for it and fix the required repairs and bring it to the required standard to continue in working order.
Do not let PG&E walk away from their responsibility and put it on everyone else else’s shoulders. Your shoulders.
These costs that PG&E is responsible for shall not come to the PG&E rate payers and customers it is the stakeholders responsibility bear the cost of their investment in PG&E and its actions or lack there of.
Until there is adequate water and a repaired maintained facility for all current communities who rely upon the water from this region, PG&E cannot be allowed to eliminate their responsibility.
Stand Strong and hold PG&E responsible, and ensure all customers, community, and environmental water needs are met.
Gregory that is the most sensible statement regarding this issue I have read. Unfortunately politics and too many unqualified people are involved.