A Sonoma County judge ruled that the county violated state environmental law in its recent attempt to pass a controversial ordinance regulating well and groundwater use across much of the region.

Chief Judge Bradford DeMeo’s ruling puts the county’s 16-month-old rule in limbo and raises questions about how it could affect the approval of new wells for rural residents and farmers across more than 300 square miles, or nearly a fifth of the county.

The district has not outlined the immediate impact of these permit applications. A district spokesman said the ruling is still under review..

The court decision is the latest twist in a years-long legal battle between environmental groups that say massive groundwater extraction is harming rivers and aquatic life. The county, the groups say, needs to study those impacts more closely and enact stricter regulations to protect natural resources that belong to the public.

“Our ultimate goal is to balance the entire system so that surface water rights holders get their fair share of the flow, groundwater pumps get a sustainable amount of water from their pumping, and aquatic life and public resources like salmon get the flow they need to survive,” said Sean Bothwell, executive director of the California Coastkeeper Alliance.

The Sacramento-based environmental group filed the lawsuit along with local organization Russian Riverkeeper on May 24, 2023, not long after the Board of Supervisors approved the ordinance in April.

In his 40-page ruling, issued last week, DeMeo found that the county failed to adequately consider the new regulation’s impact on local waterways and groundwater supplies, as required by California’s public trust doctrine, and violated the California Environmental Quality Act by claiming the county’s policy was exempt from environmental review.

The ordinance was intended to bring the county into compliance with the state’s Public Trust Doctrine, which requires local governments to protect certain waterways for public purposes, including commerce, recreation, navigation and habitat. In Sonoma County, this affects the Russian River, Petaluma River and Sonoma Creek.

According to the county permitting agency website, there are about 40,000 water wells in Sonoma County and about 23,000 properties that rely on groundwater from a private well for their primary water supply.

Environmentalists have long pointed out the cumulative impacts of this groundwater use, including on water flows and the wildlife that live in them.

The plaintiffs argued that county officials did not do enough to comply with state regulations and did not adequately analyze the effectiveness of the well ordinance in protecting natural resources.

Bothwell of the California Coastkeeper Alliance and Don McEnhill, executive director of Russian Riverkeeper, say the county’s process needs more thorough analysis and data collection regarding the impacts of groundwater extraction.

“I think that’s what was missing,” Bothwell said. “There was no data that could have really given them a long-term plan, and it felt like the county just wanted to rush it and get something on the books.”

The ordinance in question has a checkered history. It was drafted in response to a 2021 lawsuit by the California Coastkeeper Alliance that triggered a six-month moratorium on well drilling. It took nine months for the new version to pass.

In December 2022, the county agreed to pay $325,000 to settle the 2021 lawsuit.

Under the revised policy, new wells within the designated Public Trust Review Area — which covers 313 square miles, or 18% of the county — that use more than 2 acre-feet of water annually must meet new monitoring requirements and undergo a more comprehensive review process. That process would require applicants to provide additional information, including water use estimates, construction details and hydrogeological reports.

Exempt from this more stringent process are wells that use no more than 2 acre-feet of water per year and those outside the designated Public Trust Review Area. Residential wells that use up to 2 acre-feet of water are also exempt from the use of meters.

The county’s difficulties in passing such an ordinance were largely due to differing views among environmentalists, who called for more comprehensive and stricter regulations, and farmers and rural residents, who feared that stricter regulations would be a burden.

Critics of the policy called the rule too vague in its descriptions of how the county could effectively track and curb groundwater overdrafts. They questioned how the county would determine at what level of water use would require tighter controls.

The board was similarly divided when it voted 3 to 2 to adopt the regulation.

Supervisors James Gore, Lynda Hopkins and David Rabbitt voted in favor. Supervisors Susan Gorin and Chris Coursey voted against, criticizing the county’s definition of low water use and finding the plan for collecting water use data inadequate.

In his ruling, DeMeo accused the county of failing to conduct a thorough analysis and provide a resulting lack of evidence that the ordinance would effectively protect public waterways and that it was also exempt from an environmental impact assessment under CEQA, the state’s flagship environmental law.

“Here, the only evidence is that (the county) was told the change could have significant cumulative effects, but that it was impossible to determine because there was insufficient evidence,” DeMeo wrote. “(The county) ‘considered’ this issue despite the concerns by apparently choosing not to obtain the evidence and analysis it was told was required.”

The county is currently “evaluating” the impact of the ruling, said county communications manager Paul Gullixson.

“We are still reviewing the case and the board will make a decision on how to respond and whether or not to appeal. However, we have no further comment at this time,” Gullixson said.

McEnhill is confident the county will revisit the ordinance and invest in a more thorough analysis.

“There are ways to grant a drilling permit, but under certain conditions that avoid these impacts,” McEnhill said. “We believe there is a way to do that, and we hope this lawsuit takes us there.”

Reach staff writer Emma Murphy at 707-521-5228 or [email protected]. Follow her on Twitter at @MurphReports.