San Joaquin County supervisors have temporarily halted approvals for new large-scale data centers, giving county officials time to study how the rapidly growing industry could affect electricity, groundwater, agriculture and surrounding communities.
The Board of Supervisors voted 5-0 Tuesday to adopt an urgency ordinance establishing a 45-day moratorium on new land-use approvals for data centers in unincorporated San Joaquin County.
The pause comes about a month after supervisors directed county staff to spend six months studying large-scale data centers and asked County Counsel Edward J. Kiernan to determine whether a temporary moratorium could legally be imposed.
Community Development Director Jennifer Jolly told supervisors Tuesday that existing county regulations do not specifically address the characteristics of large data centers, which are becoming more common.
“The state in general is receiving an unprecedented demand for data centers due to the advancement in AI, cloud computing and digital infrastructure,” Jolly said.
Large data centers can require uninterrupted electricity and water, occupy significant amounts of land and rely on backup power generation and cooling infrastructure, Jolly said.
County staff identified several issues it plans to examine, including potential strains on the electrical grid, increased electricity costs for residents, groundwater demands, emergency response needs and effects from heat, noise, vibration and diesel backup generators.
Water is one of the county’s concerns because portions of San Joaquin County are within the critically overdrafted Eastern San Joaquin Groundwater Basin and the Tracy Subbasin, Jolly said.
The ordinance applies to approvals such as general plan or zoning amendments, use permits, variances, parcel and final maps and building or grading permits that would allow development of a qualifying data center.
The moratorium does not apply to smaller-scale data infrastructure used by hospitals, schools or individual businesses, nor does it apply to telecommunications facilities, government emergency communications facilities or facilities owned and operated by public utilities.
Jolly said the county is primarily concerned with massive facilities associated with AI uses.
“We’re really talking about like hyperscale large ones that are put together for the purposes of AI,” Jolly said. “Those are the ones that have to run nonstop, generate a lot of heat, generate a lot of noise.”
The county does not currently have a formal data-center development application pending, officials said.
However, Jolly said two specific plans currently under review list data centers as a possible future use, and she has met with a member of the public interested in potentially developing one.
If either plan is approved before the county adopts permanent data-center regulations, Jolly said the applicant would have to agree to comply with whatever rules the county ultimately establishes.
Supervisor Robert Rickman said the lack of a pending application gives the county an opportunity to establish regulations before confronting a specific development proposal.
“We don’t have any facilities at this moment. We don’t have any applications in the pipeline,” Rickman said. “So this is the perfect time to look at some of these different issues.”
He pointed to questions surrounding water and electricity use, noise, agriculture and public infrastructure. He also suggested the county consider forming an ad hoc committee that could include community members and experts in areas such as water and electricity.
Jolly said the Community Development Department is still developing a public outreach plan and recently met with a consultant to discuss assisting with the process.
The county’s action follows a similar debate in Stockton, although the city has not imposed its own moratorium.
The Stockton City Council voted unanimously Sept. 1 to remove data centers from its 2026-28 economic development plan while city officials conduct community listening sessions.
Nearly 40 people signed up to speak at that meeting, with residents raising questions about water and electricity consumption, environmental impacts and what type of data center the city wanted to attract.
The city’s economic development plan had identified data centers as a potential source of additional tax revenue but did not identify a prospective developer, location, facility size or estimates for jobs, water use or electricity demand.
Stockton already has one operating data center at the Port of Stockton.
Nautilus Data Technologies commissioned the facility in December 2020 and began serving customers the following month. The 6.5-megawatt facility supports AI, cloud storage, enterprise and local government and had about 10 customers as of earlier this year.
The city of Stockton is also a customer, paying a Nautilus subsidiary for backup data-center services used for disaster recovery and continuity of its public safety network infrastructure.
Actual electricity consumption at the port facility is not publicly available. Nautilus declined to provide the figure to Stocktonia, citing confidentiality agreements, while the port denied a public-records request for the information based on restrictions governing disclosure of individual utility customers’ electricity use.
The Nautilus facility also uses San Joaquin River water as part of its cooling system. About 6.5 million gallons of water per day can move through the system, according to regulatory records previously reviewed by Stocktonia, although that figure represents water circulated through the facility rather than the amount consumed.
The regional debate comes as data-center electricity demand is expected to rise substantially across California.
The state had more than 200 active data centers accounting for about 1,000 megawatts, or roughly 2% of peak demand on the California Independent System Operator grid, in early 2026, according to California Energy Commission figures. The commission projected demand could reach approximately 4,500 megawatts, or 9% of peak demand, by 2040.
County staff plans to return to the Board of Supervisors within six months with a broader report on the potential environmental, fiscal, public safety and public health impacts of data centers, along with policy options for regulating future development. The 45-day moratorium can be extended while that work continues.
Manteca resident Aaron Meridian urged supervisors to make that review broad enough to include privacy and surveillance concerns as well as water and power use.
“Take care of our citizens and our farmers first so each one is looked after,” Meridian said.