Petaluma Valley groundwater agency votes October 22 on its first five-year plan review

By The Downspout · Posted Oct 18, 2026 · 5 min read

The Petaluma Valley groundwater agency's board meets Thursday, October 22, 2026, 4 to 6 p.m. at the Petaluma Community Center. It will vote on accepting its first five-year review of the local groundwater plan, which says groundwater conditions stayed stable from 2021 to 2025, and on adding $250,000 to its contract with Sonoma Water, the county water agency. Staff recommend both. The board has not voted.

Where it is and what it does

The Petaluma Valley groundwater basin is the underground water supply beneath the Petaluma Valley in Sonoma County. Wells in the valley pump from it. The basin covers 46,000 acres and sits next to San Pablo Bay. The Petaluma River runs through it and into the bay.

The Petaluma Valley Groundwater Sustainability Agency, called the GSA here, is the public agency that manages that groundwater. It was formed in June 2017 under a state law called the Sustainable Groundwater Management Act. Its board has directors from five bodies: the City of Petaluma, the County of Sonoma, North Bay Water District, Sonoma Water (the county water agency) and the Sonoma Resource Conservation District.

The GSA's main document is a 20-year plan for keeping the basin healthy. The agency adopted it in December 2021, and the California Department of Water Resources (DWR, the state agency that oversees these plans) approved it in January 2023. State law says every plan must be reviewed in writing at least every five years. This is the first five-year review.

The board meets at the Petaluma Community Center. See it on a map: Petaluma Community Center, Petaluma.

What happened

The GSA posted the agenda for its board meeting on Thursday, October 22, 2026, 4 to 6 p.m. Two of the action items matter most for water. The board has not voted on either.

Short version: the review says the basin is stable, and no fee change is on the agenda.

First, the board will vote on accepting the first five-year review of the plan. The GSA calls this document the Periodic Evaluation. This article calls it the review. Staff recommend that the board accept it and send it to DWR, the California Department of Water Resources, which must receive it by January 29, 2027.

The review says groundwater conditions stayed stable from 2021 to 2025. It checked six things: water levels, water stored underground, water quality, surface water, land sinking and seawater moving inland. The plan calls a bad outcome on any of them an "undesirable result." The review says none happened. That includes seawater, which it says is not moving into the basin.

The dry years show up in the data. In 2021 and 2022, a dry stretch, one of the monitoring points used to track water levels dropped below its minimum. Levels came back in the wetter years that followed. The review still reports no undesirable result.

The review also reports how much water people pump. An acre-foot is the water it takes to cover one acre one foot deep, about 326,000 gallons. People pumped about 2,860 acre-feet a year, on average. The agency estimates the basin can sustain 8,000 acre-feet a year. That means pumping is a little over a third of the estimate.

The review also looks ahead 50 years with a computer model. If nothing changes, stored groundwater slips by about 130 acre-feet a year. That would not be an undesirable result. The review modeled one project, water-use efficiency programs. With it, the slip drops to about 110 acre-feet a year, and pumping takes about 340 fewer acre-feet a year out of streams. In June 2026 the board agreed with staff that the plan does not need to be amended at this time.

Second, the board will vote on adding $250,000 to its contract with Sonoma Water for technical work. The work includes monitoring groundwater levels, writing the annual reports and running grant-funded projects. The change moves the end date from June 30, 2027 to September 30, 2027. Of the $250,000, staff say about $8,000 covers the three extra months. About $242,000 covers work that grants are expected to reimburse and that was not expected at first. The contract's cap would rise to $2,273,800. Staff say the amendment is within the 2026-27 technical services budget, and the extension would be funded in the proposed 2027-28 budget.

The board will also hear two items for information only. One is a draft roadmap for 2027 to 2032. It would rate the basin on four action levels. Level 1 is sustainable. Level 4 is sustained bad results. Staff expect the basin to stay mostly at level 1, with level 2 in some future droughts. The other is how the three Sonoma County groundwater agencies, this one included, will hire the firm that runs their day-to-day administration. The current contract ends June 30, 2027.

What it means for you

Find out if you are in this basin. Check the water map. Then read who manages groundwater in Sonoma County.
Speak or listen on October 22. The meeting is open to the public, in person or by Zoom. The Zoom link is on the agenda at the GSA's website. The agenda says each speaker usually gets 3 minutes.
Read the review before you comment. The GSA posts the full text at petalumavalleygroundwater.org/periodicevaluation/. The comment period on the draft closed August 24, but you can still speak on October 22.
Apply for the Advisory Committee by October 30. The GSA's Advisory Committee is taking applications for seats for agriculture, environment, rural residential, business and community at large. Terms run January 2027 through December 2028. Find the application on the GSA's website.
Help the data, if you have a well. Two voluntary programs involve well owners. Level Up! measures water levels in private wells, and the review says it has engaged 20 well owners. Flow Smart meters how much a well pumps. The review says Level Up! helped fill gaps in water-level data and Flow Smart improved understanding of how much is pumped. The GSA's phone number is (707) 243-8555.
Know the fee picture. The GSA collects a groundwater sustainability fee through tax rolls and direct invoices. In June the board voted 5 to 0 to raise the fee for 2026-27 to match inflation, according to draft minutes. The same minutes say 2026-27 is the last year the County has committed to help pay toward the fee. The Sonoma County groundwater agencies have asked consultants to apply to run studies of the fee for the next five years. No fee change is on the October 22 agenda.

What happens next

The board votes on October 22. The review goes to DWR by January 29, 2027.

In November, staff plan to send the draft 2027 to 2032 roadmap to the Advisory Committee for comment, and the board could accept it in January or March 2027. The hiring notice for the administration contract is planned for November 2026, and the new contract would start July 1, 2027.

Where this came from

The Petaluma Valley GSA board agenda and meeting packet for October 22, 2026. The packet holds the staff reports, a summary of the review, the draft contract change and the draft minutes of the June 25, 2026 meeting. Background on the agency and the plan comes from the GSA's home page. Everything above about October 22 is a staff recommendation or a proposal until the board votes.

Sources

Checked 2026-10-18. Rules and programs change. If something here is out of date, the source above wins. Spot an error? See our corrections policy.