A large data center can consume more water in a day than a city the size of San Luis Obispo, according to a report by the Environmental and Energy Study Institute. The California legislature passed a bill this year that would have required data centers in California to report their water usage on business reports.
Governor Gavin Newsom vetoed the bill, AB 93, last year because of the “unprecedented demand for data center capacity” due to artificial intelligence. Newsom seemingly sided with tech innovation, but legislators say a bill like this would have provided more localities with necessary information to protect water sources.
“This bill really represents the inflection point between innovation and sustainability,” said Diane Papan, the state assembly member who authored the bill. “I was really trying to reach that balance, especially when you’re talking about a resource like water. You can’t generate more water.”
With Waymos driving through the streets and tech giant headquarters on every corner, California’s Bay Area is seen as a place for innovation. This innovation often comes to a head with environmental issues, according to Papan, who represents most of San Mateo County.
But for a place like San Luis Obispo, a small town compared to major metropolises north and south, will the water supply be able to support technological advances? Should San Luis Obispo residents worry about big tech coming to the Central Coast in the first place?
Why do data centers need water? How much do they use in California?
Data centers are buildings that store and process a lot of digital information, like videos, websites and AI programs. Most electricity generation uses water, so data centers indirectly drive large off-site water use. Since the computers get very hot, many data centers use water-based cooling systems to keep them running.
In California, data centers used about 50 billion liters of water in 2023, which is about 20,000 Olympic swimming pools, according to a new report from researchers at the University of California, Riverside. Water use related to California data centers is projected to reach up to about 116 billion liters, or about 47,000 Olympic swimming pools, by 2028, according to the report.
How will Cal Poly’s new AI Factory address environmental impacts?
Cal Poly is opening a new AI Factory that will use four NVIDIA supercomputing systems to support research and teaching across campus. The facility is expected to be fully operational in March and will be located in Building 14, according to the director of the Noyce School of Applied Computing Chris Lupo.
The data center will allow Cal Poly researchers to create their own AI models and store the data on Cal Poly’s campus, but the center will be very small compared to the water-guzzling facilities in the Silicon Valley.
READ MORE: Cal Poly to build $3 million AI Factory with NVIDIA partnership
Campus Information Technology consolidated several of Cal Poly’s business and enterprise workloads, which allows sufficient energy capacity in the data center, according to university spokesperson Keegan Koberl. He says Cal Poly carefully considered the environmental impact of the deployment of the facility and will use an air cooling system.
Are there any existing data centers in San Luis Obispo?
San Luis Obispo has four private data centers. From publicly available information, these data centers are relatively small. The facilities are less than 50,000 square feet, according to a data center information aggregate. Some large data centers cover hundreds of thousands of square feet.
To put in perspective, the San Luis Obispo data centers are a little smaller than a single football field, but large data centers can be as large as almost 10 football fields, like some in the bay area. A company would likely need a special permit for a large data center facility in San Luis Obispo because the city’s zoning rules do not list data centers under an existing specific category.
Could AI affect any of San Luis Obispo’s resources?
The city is not currently facing any imminent water shortages. Two of San Luis Obispo’s three main water reservoirs, Nacimiento and Whale Rock, are near full capacity, according to the city’s utility department. And the third reservoir in Salinas filled over capacity.
Even if there is no large data center in San Luis Obispo anytime soon, AI could still affect the city. San Luis Obispo depends on the same statewide electrical grid as the rest of California, and the increasing use of AI could put more strain on the system.
The UC Riverside report shows that AI-driven data centers nearly doubled their electricity use in California between 2019 and 2023 and could drive even greater demand in the years ahead.
How would AB 93 have changed data center water-use transparency?
AB 93 would have required data centers to tell their local water supplier how much water they expect to use, and then report their actual annual water use every year when renewing a business license. The owner would have to self-certify this information under penalty of perjury.
Researchers can estimate how much water data centers use statewide, like in the reports referenced in this article, but these estimates do not show how much water a single facility uses in a specific community.
Companies are not required to report that information publicly as of now, so cities and water districts often lack exact data when approving new projects. The author of the bill hoped to prepare localities for the age of AI.
“I really felt like this was an opportunity to lead and tell the rest of the nation, ‘hey, data centers may use a lot of water, but this is a way of at least preparing yourselves for that water demand,’” Papan said. “My feeling is let Texas run out of water. We don’t have to be the same.”
What is the future of innovation vs. environment legislation in California?
Rapid technology growth and long-term environmental protection are starting to collide more frequently in California. Lawmakers say this tension will shape future policy, especially as AI drives the need for more data centers. These facilities require large amounts of electricity and water, two resources already under pressure across the state.
“Data centers would prefer not to release their individual water or electricity consumption,” State Senator John Laird said. “If local governments and planners don’t have that knowledge, it’s hard to plan for adequate water or adequate electricity.”
Laird, who represents the northern part of San Luis Obispo County, supported AB 93 and thinks there will still be an appetite for this type of bill in the future. He thinks Newsom’s veto could just be a speed bump.
“We are also entering a strange period of time where this is about to be the governor’s last year,” Laird said. “When the governorship changes, there’s always this big run in the first year to try to do legislation that the previous governor vetoed. So who knows?”