California depends on snowpack, reservoirs, groundwater, rivers and major water-delivery systems to serve nearly 40 million people, farms, ecosystems and businesses. New high-demand development should be evaluated with the full water picture in view.
California's water system has always had to bridge wet years and dry years. Climate change is making that job harder by changing snow accumulation, snowmelt timing and heat. The Department of Water Resources notes that Sierra Nevada snowpack acts as a natural reservoir and, on average, supplies roughly 30% of California's water needs.
At the same time, data-center development is expanding. The California Energy Commission tracks the industry's growing electricity demand and certain backup-generation projects, although local governments—not the CEC—generally handle data-center land-use approvals.
Before approval, communities should be able to see the proposed water source, annual and peak-day use, cooling technology, drought restrictions, conservation measures and infrastructure costs.
Share of California's water needs supplied on average by Sierra Nevada snowpack.
California DWRExisting California data-center peak demand in early 2026—about 2% of California ISO peak demand.
California Energy Commission, 2026Approximate combined administrative and data-center space proposed for Microsoft's two-building San Jose Data Center.
California Energy CommissionCalifornia can move out of drought after storms while still facing long-term risks from heat, groundwater depletion and shrinking snowpack.
California DWR / State of CaliforniaCalifornians depend on interconnected reservoirs, rivers, aqueducts and groundwater basins rather than a single water source.
California DWRThere is no single water-use number that applies to every California data center; design and cooling choices matter.
CEC / LBNLSnow stores winter precipitation and releases it into rivers and reservoirs as temperatures warm. Hotter conditions can cause earlier melt and reduce how long this natural storage lasts.
Major reservoirs capture runoff for cities, farms, flood control and environmental needs. Reservoir levels can be healthy statewide while individual watersheds still face local constraints.
Groundwater is critical during drought, particularly for agriculture and communities not served by large surface-water systems. Heavy pumping can lower water tables and create long-term problems.
California moves water long distances through the State Water Project, Central Valley Project and local systems. That means water demand in one place can connect to conditions far away.
Water can be evaporated to remove heat efficiently, which consumes water directly at the site.
These can reduce direct water demand but may involve energy or performance tradeoffs during high temperatures.
Closed-loop liquid cooling and reclaimed-water systems can reduce demand for drinking-quality freshwater depending on project design and local infrastructure.
California's climate makes peak hot-weather demand especially important. A project that looks modest on an annual average can still place a large demand on a utility during the hottest part of the year.
California is already one of the country's largest data-center markets. Counts vary because different databases define a “data center” differently: some count individual buildings, some campuses, and some only projects with known power capacity. For that reason, this page keeps government electricity-demand figures separate from commercial project-count databases.
Operating California projects listed by Cleanview in August 2026.
Commercial project tracker; definitions differ by datasetCombined operating capacity listed for those 53 projects.
Cleanview, Aug. 2026Planned projects in the same tracker.
Cleanview, Aug. 2026Additional planned capacity listed by the tracker.
Cleanview, Aug. 2026CEC forecast of data-center peak demand from early 2026 to 2040.
About 2% → 9% of CAISO peak demandSanta Clara remains a core market, while new proposals are spreading to Los Angeles, Sacramento, Gilroy and Imperial County.
CEC / local planning agencies / project trackersThe California Energy Commission measures electric demand across the grid, while commercial databases count facilities and projects. A campus may contain several buildings, and “capacity” can mean utility load, critical IT load or generation capacity. We show the source beside each number so visitors can judge it accurately.
The capacities below come from Cleanview's August 2026 California project tracker unless otherwise noted. Operator-reported “critical IT capacity” can differ from the tracker’s project-capacity figure.
83 MW in Cleanview's project database; Vantage itself describes CA3 as having 64 MW of critical IT capacity. The campus is about 486,000 square feet and became operational in 2025.
60 MW listed by the industry tracker in Santa Clara.
49 MW listed in Alameda County, operational in 2022.
47 MW listed by the tracker, with 2026 operation noted.
39 MW listed in Santa Clara, with 2023 operation noted.
Each is listed at about 36 MW by the tracker. Project status and commissioning dates should be checked directly with operators and local agencies.
Commercial trackers have listed a Terra project at up to 417 MW. Terra's own public site describes a design with 99 MW of on-site power, showing why capacity definitions and project phases need to be checked carefully.
A proposed 330 MW, roughly 950,000-square-foot project in Imperial County has become a major water and land-use controversy. Reporting in 2026 described disputes over access to water and environmental review.
Industry trackers list a proposed 100 MW AI-focused project associated with Naval Air Station Lemoore, with a 2027 target.
Industry trackers list a roughly 97 MW planned project in the San Jose/Santa Clara market with a later-decade target.
The City of Gilroy says AWS proposes a two-phase data center on a 56-acre site with two data-center buildings and a security building totaling about 438,500 square feet. Local project documents are the best source for current status and environmental review.
Additional projects tracked in Los Angeles and Sacramento include Digital Realty, HMC Capital and Prime Data Centers developments. Their sizes, schedules and approvals can change, so this page treats them as projects to watch rather than guaranteed builds.
The California Energy Commission says data centers represented about 1,000 MW of peak demand in early 2026 and projects that figure could reach about 4,500 MW by 2040. That makes electricity, water, backup generation and local infrastructure planning increasingly connected issues.
In Gilroy, Amazon Web Services is building a two-phase data-center project on about 56 acres, with two data-center buildings and a security building totaling roughly 438,500 square feet. The City of Gilroy's project page confirms the size and site details.
Recent reporting by The Wall Street Journal described strong community backlash because the project moved through an industrial-zoning approval process without a City Council vote or public meeting specifically approving the data center. Many residents said they did not realize the project was coming until construction was underway.
Residents have raised concerns about water, drought, infrastructure and the lack of early public engagement. Amazon says it followed the standard approval process for the industrially zoned site and has since held meetings and an open house with residents.
A project can be legally permitted and still leave residents feeling shut out of the decision. Gilroy is a reminder to ask about major water- and power-consuming projects before public-comment windows close and construction begins.
Questions to ask: Is a public hearing required? When does environmental review close? What water source and drought plan are proposed? Will neighbors receive direct notice?
New projects are increasingly designed around AI and cloud workloads, which can require much denser computing and large amounts of electricity.
Developers are looking beyond Santa Clara toward Gilroy, Sacramento, Los Angeles and Imperial County where land, energy or transmission opportunities may differ.
Renewable-energy access does not eliminate freshwater concerns. Each project should disclose cooling design, water source, peak demand and drought strategy before approval.
Santa Clara County has long been one of California's core data-center markets. The California Energy Commission lists projects including Microsoft's proposed San Jose Data Center with two buildings totaling nearly 397,000 square feet.
Existing technology infrastructure, fiber networks and business demand continue to make the Bay Area attractive for data-center growth. Water planning should be considered alongside electricity and backup generation.
Los Angeles, Orange County and the Inland Empire are also seeing digital-infrastructure demand. Hotter inland temperatures can make cooling-water and peak-energy questions especially important.
California does not have a single state agency that approves all data centers. That makes local planning documents, environmental review and utility filings important places for residents to look for project-specific water information.
The Sierra Nevada snowpack has historically released water from spring into summer. DWR now warns that warming is changing the timing and reliability of that pattern. Even when winter storms bring relief, heat can rapidly reduce snow-water storage.
This matters for every new long-lived water demand. A data center can operate for decades, so planners should evaluate future climate and drought conditions—not only today's reservoir level.
California can have full reservoirs and little drought on a statewide map while still facing groundwater decline, ecosystem stress or vulnerable local water systems. Long-term planning has to look beyond a single season.
What are projected annual, average-day and peak-day water demands?
Is the source drinking water, groundwater, surface water or reclaimed wastewater?
Will the facility reduce water use when residents and businesses are under conservation rules?
What alternatives were evaluated, and why was the proposed cooling system selected?
Will new water and power infrastructure increase costs for existing customers?
Will actual annual water consumption be reported so the public can compare it with projections?
California is enormous. A statewide reservoir percentage cannot tell you whether a particular groundwater basin, small water system, river reach or local reservoir is under stress. That is why this project wants photographs, dates and local observations from residents across the state.
We also want to distinguish between water withdrawal and water consumption. Water that is withdrawn and returned is different from water that is evaporated and no longer available locally. Project documents should be clear about both.
Upload your own dated picture of a river, lake, reservoir, stream or other freshwater condition. Photos are reviewed before public posting.
Save Our Fresh Water is an independent public-awareness project. Links are included so visitors can verify claims and follow changing conditions directly from government and research sources.