The San Mateo County Board of Supervisors on Tuesday began making plans to look into changing its zoning rules to restrict the construction of data centers in the county’s unincorporated areas.
“What we are contemplating is taking an initial step to assess what is best for our communities, our residents, and our local economy,” said Supervisor Lisa Gauthier, a sponsor of the resolution.
Data centers are physical spaces with computing equipment that stores, manages, and processes datasets. They’re used to train and compute the workloads of artificial intelligence, but they can come with environmental costs since they use large amounts of water and energy,
“Data centers run 24 hours a day and require consistent power, which also means that they often employ backup generators, typically powered by diesel fuel,” Gauthier said. “That means potential emissions.”
Despite growing pushback in the region, developers are eyeing locations for possible data centers. One is under construction in the South Bay in Gilroy. Gauthier said that the San Mateo County Event Center was solicited as a potential site.
While Gauthier said that the county doesn’t have enough land or water to support data centers, its proximity to Silicon Valley and the hub of AI growth is enough concern to consider adding data center limitations in its zoning rules.
“Our region, Silicon Valley, is a hotbed of potential data center development with numerous projects in some phases of planning or development,” Gauthier said. “We should prepare, recognizing that we have a responsibility to do so.”
The resolution directs the Planning and Building Department to work with the County Executive’s Office and the County Attorney’s Office to assess appropriate amendments to zoning regulations.
The resolution originally included consideration of a countywide ban on new data center construction, but other supervisors saw that aspect as too strict.
“It presupposes in the resolution that this will be a countywide ban,” said Supervisor Jackie Speier. “I would rather us consider all the elements as opposed to going immediately to a countywide ban.”
Balancing growth and environmental concerns
Gauthier proposed convening a meeting with organizations like the Silicon Valley Leadership Group and others to help guide the policy. The advocacy group is made up of leaders and CEOs from hundreds of regional companies, a majority from the tech industry. Gauthier is the group’s former senior vice president of inclusion and belonging.
Eric Negomir, Silicon Valley Leadership Group’s associate for regional government affairs, said during public comment that the group is in favor of a balanced solution in allowing new data centers.
“We support a collaborative approach that allows data centers to deliver significant tax revenues and infrastructure upgrades without harming local residents’ quality of life,” he said. “Already, Silicon Valley’s leading companies are deploying real, innovative, and at-scale solutions to drastically reduce water consumption and address other key concerns.”
Several cities in the region, like Gilroy, San Francisco, and Oakland, recently hit the pause the button on data centers by adopting temporary moratoriums, giving governments time to evaluate and craft more permanent legislative solutions.
San Mateo County’s turn to address the issue by starting to evaluate a possible data center policy passed with majority approval, without including consideration of a countywide ban as originally written in the proposal. Board President Noelia Corzo, who co-sponsored the resolution, and Supervisor David Canepa were both absent from the meeting during the vote.
