AB 93: Regulating Water Usage in Data Centers

Brody Friedeberg

Early September is a busy time in the California State Legislature. It has been less than a month since the legislature reconvened after Summer Recess, and while fiscal committees were required to report bills to the Floor by 8/29, no committees will be allowed to meet until 9/12, the deadline for each house to pass bills (California State Legislature, Senate 2). One bill that I find particularly interesting, given the widespread community concerns around sustainable development, is AB 93. Introduced by my local Assemblymember, Diane Papan, AB 93 aims to regulate water usage in data centers with the goal of greater efficiency. It focuses on sustainable water use in a technological space where sustainability may not always be a primary concern (“California Assembly”). 

An article published this summer by the Environmental and Energy Study Institute (EESI) indicates that large data centers can consume an amount of water that is equivalent to the water usage of a city with up to 50,000 residents (Yañez-Barnuevo). While there are several areas in the United States with high concentrations of data centers, California comes in third place in terms of states with the most data centers. Silicon Valley, and more broadly, the Bay Area, are home to the vast majority of these California data centers (“USA Data”). The EESI article elucidates that most data centers use complex, water-intensive cooling practices involving blue water, which stems from natural bodies of water (Yañez-Barnuevo). Data centers also indirectly use an incredible amount of water through the electricity that they need for operation. The way in which the electricity is produced, in majority from fossil fuels, requires large amounts of water as well.

Given the local environmental risks that come from data centers’ use of water and Assemblymember Papan’s track record of supporting sustainability bills, it makes sense that she would want to further regulate water usage in data centers (“Bills”). AB 93 would amend the California Business and Professions Code and Water Code with additions that regulate business license applications for data centers. For one, data center owners or operators would have to submit an estimate of the expected water use and a report of the annual water use to their water supplier in order to be able to receive a business license. In addition, following a year-long lag time, data center owners or operators would have to agree to meet any new guidelines passed by the Department of Water Resources. AB 93 was recently read a second time in the State Senate and is awaiting its third reading before being voted upon (“California Assembly”). 

While AB 93 is seemingly uncontroversial, it does have both organizational supporters and opponents, so it could face pushback if adopted (“AB 93: Water”). Opponents of AB 93 include some of the largest tech companies in the Bay Area and the world, including Amazon, Google, Meta, and Oracle, as part of the Data Center Coalition (“DCC Members”; “Top 10 Largest”). 

If the bill were to be passed, data centers might adhere to the new regulations, adapt with alternative methods of cooling, or move out of California entirely. It does not seem like the bill would affect the lives of most Californians. In the long run, though, we have a relatively small, finite supply of fresh water available to us. Concern has been raised about the Hetch Hetchy Reservoir being affected by climate change as it is, and with California being especially prone to droughts, water use regulation is pertinent (Cruz Guevarra and Romero; Mount et al.). As such, AB 93 could have an impact in the future on sustainable technological development and water use in California.

Image credit: Wikimedia Commons

Works Cited

"AB 93: Water Resources: Data Centers." CalMatters Digital Democracy, CalMatters, calmatters.digitaldemocracy.org/bills/ca_202520260ab93.

"Bills." CalMatters Digital Democracy, CalMatters, calmatters.digitaldemocracy.org/bills?site=ca-calmatters&author%5B%5D=165423&session_year%5B%5D=2025-2026.

"California Assembly Bill 93." LegiScan, legiscan.com/CA/bill/AB93/2025.

California State, Legislature, Senate. 2025 Tentative Legislative Calendar. 16 Oct. 2024, www.senate.ca.gov/system/files/2024-10/2025-proposed-calendar-updated.pdf. 2025th Legislature.

Cruz Guevarra, Ericka, and Ezra David Romero, hosts. "Yosemite's Hetch Hetchy Reservoir in the Era of Climate Change." The Bay, KQED, 10 May 2023. KQED, www.kqed.org/news/12054241/yosemites-hetch-hetchy-reservoir-in-the-era-of-climate-change.

"DCC Members." Data Center Coalition, www.datacentercoalition.org/members.

Mount, Jeffrey, et al. Droughts in California. Public Policy Institute of California, Apr. 2021. Public Policy Institute of California, www.ppic.org/publication/droughts-in-california/.

"Top 10 Largest Tech Companies in the World by Market Cap in 2025." Forbes India, Network18, 1 Aug. 2025, www.forbesindia.com/article/explainers/top-tech-companies-world-market-cap/95180/1.

"USA Data Centers." Data Center Map, www.datacentermap.com/usa/.

Yañez-Barnuevo, Miguel. "Data Centers and Water Consumption." Environmental and Energy Study Institute, 25 June 2025, www.eesi.org/articles/view/data-centers-and-water-consumption.