The future of water security in Potter Valley took center stage at a November 14 town hall, where experts and community leaders outlined plans to adapt to life without year-round Eel River diversions. With PG&E’s decommissioning of the Potter Valley Project looming, discussions focused on potential groundwater storage, new infrastructure, and conservation measures—all aimed at ensuring local agriculture survives a drier summer reality.
The meeting was hosted by the Potter Valley Irrigation District (PVID) and Jacobs, a consulting firm hired to study groundwater and potential water storage solutions in Potter Valley. Janet Pauli, a member of PVID’s Board of Directors, opened the meeting. Pauli also serves on the Board of the Inland Water and Power Commission of Mendocino County and the Board of the Eel Russian Project Authority. She has been advocating for water security in Potter Valley for years. Many board members and staff from these entities attended the meeting, along with representatives from Sonoma Water. Outgoing District 1 Supervisor Glenn McGourty and Supervisor-Elect Madeline Cline were also present.
Historically, Potter Valley and downstream users along the Russian River have depended on water from the Eel River, stored in Lake Pillsbury behind Scott Dam and in Van Arsdale Reservoir behind Cape Horn Dam. The water has been diverted through a tunnel into Potter Valley, where it flows into the East Branch of the Russian River, continues into Lake Mendocino, and ultimately serves users in Sonoma County. Locally, the diverted water has been critical for agricultural irrigation in Potter Valley.
This system, in place for over a century, initially supported hydroelectric power production, with water as a byproduct. However, since 2019, when PG&E announced it would not renew its license from the Federal Energy Regulatory Commission to operate the Potter Valley Project, local governments, water agencies, and NGOs have sought solutions to restore Eel River fisheries while ensuring water security for Russian River users.
After years of discussions, stakeholders from the Eel and Russian River basins agreed that Russian River users would pursue and fund a new seasonal diversion of Eel River water after the removal of the dams. The goal is to support fisheries restoration while addressing water needs. However, the seasonal diversion, designed to operate only during the wetter months (November to May), would leave Potter Valley without diverted water during the dry summer months, heightening the importance of winter water storage.
Currently, the Inland Water and Power Commission (IWPC)—comprising the Mendocino County Water Authority, City of Ukiah, Redwood Valley County Water District, PVID, and the Mendocino County Russian River Flood Control and Water Conservation Improvement District—along with Sonoma Water, aims to build this new seasonal diversion. The groups are negotiating with PG&E to include the plan in its final surrender application for the Potter Valley Project.
Meeting Highlights and Expert Input
Janet Pauli summarized the meeting’s purpose: “The reason we are here tonight is to find out what they are learning about the potential to store water in Potter Valley that we have coming through the diversion in the wintertime.”
IWPC Consulting Engineer Tom Johnson discussed the timeline for PG&E’s surrender and the decommissioning of the dams. PG&E plans to file its final surrender application in mid-2025. Johnson estimates that the process could take two to three years if all goes smoothly, but delays could extend it significantly. The dams might be removed by 2028, though it could take until 2031 or beyond. Johnson emphasized the urgency of developing a water storage strategy before the decommissioning process concludes.
The proposed seasonal diversion would be built at the site of Cape Horn Dam. While the dam itself would be removed, a sill—a low wall at the dam’s base—would remain. The plan includes a new pump station and continued use of the existing tunnel. This alternative, selected after extensive negotiations between Eel River and Russian River stakeholders, is considered the best compromise.
Without Eel River water during summer months, Potter Valley would face a significant water deficit. Winter water, if stored, would primarily flow to Lake Mendocino and support downstream users. Returning water stored in Lake Mendocino to Potter Valley would be cost-prohibitive, and local access to Lake Mendocino water is complicated by existing water rights. While raising Coyote Valley Dam at Lake Mendocino is a potential long-term solution, it is costly and years away from implementation.
Groundwater Studies and Storage Options
Jacobs engineers Armin Munevar and Nate Brown detailed their analysis of groundwater and storage potential in Potter Valley. They reviewed data from U.S. Geological Survey (USGS) reports and a 2021 McMillan Consulting study, utilizing advanced techniques such as satellite imagery, drone surveys, and electromagnetic measurements. PVID’s water use records, spanning 12 years, informed their study. Five monitoring wells were drilled, three of which are already outfitted with equipment to gather data on groundwater levels.
Jacobs explored various storage solutions, including new dams on Potter Valley streams or the East Branch of the Russian River, as well as expanding existing pond storage. Building dams would require significant investment and time; tributary dams would need to be 100 to 200 feet tall, while a dam on the East Branch would require a height of 20 to 40 feet. Expanding frost protection ponds could provide up to 6,000 acre-feet of new storage, tripling current capacity.
The consultants also assessed water conservation strategies, such as replacing irrigation canals with pipes to reduce seepage and evaporation losses, which currently amount to 6,000 acre-feet annually. Improved agricultural irrigation techniques could save an additional 1,000 to 3,000 acre-feet.
Q&A Session
The proposed solutions come with hefty price tags, ranging from $20 million to $200 million. How will it be funded? Officials anticipate a mix of state and federal grants, with some local cost-sharing.
Long-term maintenance of the tunnel was another concern. While a detailed cost analysis for repairs 30 to 50 years down the line hasn’t been completed, the Eel Russian Project Authority is expected to oversee its operation and maintenance.
With the dams projected to come down in the next 4 to 10 years, the urgency to implement feasible solutions has intensified. Potter Valley’s reliance on diverted water means it faces a more immediate crisis than areas downstream of Lake Mendocino, which have access to the reservoir. Securing grants—potentially through recently passed Proposition 4, which allows bonds for conservation projects—will be critical to funding water storage and infrastructure upgrades.
Outgoing Supervisor Glenn McGourty reassured attendees he will continue advocating for North Coast water infrastructure, even after retirement. He emphasized the region’s historic lack of investment compared to Central and Southern California.
As for Sonoma County’s role, Deputy Chief Engineer Don Seymour clarified that Sonoma Water’s primary interest lies in securing the transfer of Eel River water, not Potter Valley itself. “The more partners to help pay for it, the better,” he said, adding that Sonoma will continue supporting grant applications.
Several technical questions were raised. Why prioritize Busch Creek for a reservoir? Its geography and elevation would allow for nearly double the storage of other sites. What about shallow domestic wells? Protecting these wells will require careful planning, as Potter Valley currently lacks an agency providing treated domestic water.
Decision-making will ultimately rest with the community, with opportunities for public input as PG&E’s surrender process unfolds. Early actions, such as developing storage ponds and drilling new wells, could help reduce uncertainties.
Slides from the Town Hall will soon be available on Sonoma Water, IWPC, and PVID websites, with voiceover narration to address sound quality issues from the meeting.
Closing Remarks
Janet Pauli concluded the meeting by urging attendees to stay informed about PG&E’s surrender process and emphasized the importance of continued community involvement. She stated, “The cost estimates are really important for us to understand.”
Memorable Moment
A supporter of The Lake Pillsbury Alliance expressed frustration with PG&E during the Q&A, exclaiming, “Hi everyone, I don’t have a question. I have Save Lake Pillsbury hats for sale. Love you, Potter Valley, fuck you, PG&E!” Trucker caps with the alliance’s Save Lake Pillsbury logo were available for purchase after the meeting.*
Slides from the Town Hall will be posted online at Sonoma Water, IWPC, and PVID websites once a voiceover narration is added to improve sound quality.
*Hannah Foster contacted us to clarify she is not affiliated with the Lake Pillsbury Alliance and clarified that she sells the trucker hats to raise awareness and donates the proceeds after covering her costs. She emphasized that her public statement at the Town Hall reflects her personal views and does not represent the Lake Pillsbury Alliance’s stance on PG&E.
This whole endeavor doesn’t make sense. The desired outcome of restoring a fishery is uncertain as to whether it is attainable. It is based on the premise that if the water temperature from this branch of the Eel goes back to what it was hundreds of years ago, the fish will come back. We don’t hear about the impacts of over fishing in the Pacific or the chemicals that get into the watershed from illegal grows.
The consequences of going through with the endeavor, however, are certain. The riparian habitat of the Russian River in place for over 100 years will suddenly and irreversibly change. The environmentalists driving this seem to have a myopic focus on something that may never be and ignoring what will certainly be.
The whole talk about fishery importance is a side topic at the consequence of PG&E moving out its assets away from this Dam. Prior to PG&E announcing they were relinquishing the obligations of this Dam the fisheries had no issue with the hydro-electric Dam. The regional area doesn’t have enough economic generation here to maintain this Dam so that’s the pink elephant of this whole topic. Water is going to cost more so I would get smart around water infrastructure.
For almost everyone affected by the proposed (I refuse to call it immanent) destruction of the Potter Valley Project, it is not really a big deal,
Some Humboldt folks think it will make up for a hundred years of mismanaging their water courses and over-fishing the rivers and the ocean and bring back salmon and steelhead runs. Won’t.
For the urban areas down south it will let them continue to over-build and under-conserve.
Redwood Valley stands to get more Potter Valley water than ever.
Potter Valley faces social and economic catastrophe. 100 years of reasonably careful use of very nearby resource to build an agricultural community will simply be lost with the loss of summer water. Period.
Weighing its huge loss against others’ small gains makes stopping the Two Basin “Solution” simply necessary.
The residents of Potter Valley can and should be expected to fight the plan by all means possible.
100 years of reasonably care use ? The fucking took water from one river and like reverse-watersheded it to make potter a swamp when it was traditionally one of the driest valleys. Smh
Technology is right, this is all a symptom of big dams being too expensive to maintain once they get old. No one wants to pay what it costs to keep the dam and it’s uncertain if paying to keep the water makes any sense. I suspect irrigators in potter valley that are used to abundant free water are going to have sticker shock when they see what the water actually costs. As for the guy in the article saying “F PG&E”, the entitlement is rich. Ratepayers have been maintaining this money losing albatross for years while electric rates go up, but I guess if you own a lake house and a speedboat you can act aggrieved.
In addendum to your comment, the fires in Mendo and Sonoma really whacked PG&E financially due to the rural sprawl of these communities. Redwood Valley (and if I’m not mistaken Potter V too) now requires fire sprinkler systems in all new construction not to mention elevated property insurance rates. The winery maintenance crews accidentally started the Cow mountain fire which morphed in to the Mendo complex fire in 2018. If Mendo were move away from Ag as an industry, this area probably would have enough water for larger urban centers. A tax base that can afford the roads and infrastructure around it. Farms don’t pay much in taxes and receive many tax funded subsidies from Fed and State entities. Many vineyards are tax write-offs for affluent landowners. Let’s not forget the local regional Ag areas consumes way…way more water than all the Urban core areas in Mendo and Sonoma combined.
“Abundant free water.”
Do you know anything about Potter Valley?
Just another future dry valley if PV can’t figure out how to make their economy work for them.
The River used to run dry in the summer months and the fish survived. Ag land is essential! The water is essential to all the farms and people who depend on it, including our economy. PGE is not using it for hydroelectric power. We need to find a way to keep the water flowing to our communities. Drought is only going to get worse, and water needs to be stored. The raising of Coyote Dam is expensive, but maybe it could be part of a solution. Hopefully, a plan to keep water flowing to our communities can come to fruition.
I believe the cost of putting a fish ladder on Scotts dam was $19 million and that was deemed to be too expensive, but $20-$200 million to build new dams and diversions to make up for the water that is already there is on the table? How many salmon were counted at the fish ladder in Potter Valley this year? Are the lives of the bald eagles, ospreys, and elk that rely on that lake worth nothing or will they just have deal with it like the people in Potter Valley who have spent generations building lives for themselves. Spend the money to update the existing infrastructure that is already in place. Stop trying to cause a problem that fits your solution.
The Eel River’s water belongs in the Eel River and should be allowed to stay there. Both dams should
be torn down and the tunnel destroyed. Folks should learn to live with the water they have, not the water they might wish for.
[…] “The future of water security in Potter Valley took center stage at a November 14 town hall, where experts and community leaders outlined plans to adapt to life without year-round Eel River diversions. With PG&E’s decommissioning of the Potter Valley Project looming, discussions focused on potential groundwater storage, new infrastructure, and conservation measures—all aimed at ensuring local agriculture survives a drier summer reality. … Historically, Potter Valley and downstream users along the Russian River have depended on water from the Eel River, stored in Lake Pillsbury behind Scott Dam and in Van Arsdale Reservoir behind Cape Horn Dam. The water has been diverted through a tunnel into Potter Valley, where it flows into the East Branch of the Russian River, continues into Lake Mendocino, and ultimately serves users in Sonoma County. Locally, the diverted water has been critical for agricultural irrigation in Potter Valley. … ” Read more from the Mendocino Beacon. […]
Article Correction: The trucker hats mentioned in the article are not sponsored by the Lake Pillsbury Alliance, The hats are created and sold by an independent designer and we really appreciate the support we receive from this grassroots effort!
I think rain water collection and storage by both the residents and land owners between the diversion tunnel and lake Mendocino should be implemented asap. Just a suggestion to consider