1 in 4 data centers sits in a water-stressed area. Few states track how much water they use

A new global study maps where data centers overlap with water shortages, but not how much water they draw. U.S. states are only beginning to collect that number, and getting it has been hard.

The study, published in Environmental Science & Technology, found that 2,315 of 9,347 data centers worldwide, about 25%, are located where water demand already exceeds renewable supply at least one month a year, based on 2001–2010 water conditions. If global temperatures rise 3°C above preindustrial levels, which the authors’ climate models reach between about 2039 and 2068 under a high-emissions scenario, that share rises to about 33%.

Data centers “typically have the financial capacity and institutional priority to secure water supplies whenever water is available,” the authors wrote, so “the primary risk may not be to data center operations themselves but to other water users within the same basins.” Because water allocation rules often favor data centers over farms and ecosystems during shortages, the authors added, current assessments likely underestimate the effects on “less economically or politically powerful users.”

“These facilities are not landing in empty landscapes. They are landing on top of the water supply of cities and farms,” Lorenzo Rosa, a water-scarcity researcher at the Carnegie Institution for Science who led the study, said in a statement.

The study could not access data on capacity, cooling type or water use. Instead of estimating facility-level consumption, the study measured exposure, or whether each data center sits in an area where water demand outstrips supply. The authors call their estimates of water shortfalls an upper bound, because the model does not account for reservoirs, water transfers, desalination or water rights. The count of data centers may also be incomplete. The authors relied on a proprietary list from Saoradh Enterprise Partners that they said “likely underestimates the true global count, particularly for undisclosed, smaller, or newly constructed facilities.”

The study counted 3,619 data centers in the U.S., or 39% of the global total. Of those, 764 (21%) are in water-scarce areas. With 3°C of warming, that rises to 1,269 (35%).

Reluctant to report

Data centers have been hesitant to report their water use. For example, the Western Virginia Water Authority redacted how much water a planned Google data center would use, citing a nondisclosure agreement. A local news outlet sued and, after repeated rulings, the authority released the project’s planned water use in February: 2 million gallons a day and up to 8 million gallons a day if the project expands. The initial amount is nearly eight times what the authority’s largest current customer, a Coca-Cola bottling plant, uses. Before the release, Google’s lawyers joined the authority in asking an appeals court to block a judge’s order, and the court declined. The authority’s director, Mike McEvoy, said this was the first time a confidentiality agreement had stayed in force after a project was announced.

Only a few states require data centers to report water use. A New Jersey law signed Aug. 27 requires semiannual reports to the state Board of Public Utilities on total and peak daily water use and its sources, including whether the water is potable or reclaimed. The board must publish that water and energy use information on its website within 30 days of receiving it. On Sept. 21, California Gov. Gavin Newsom signed a law requiring data centers to report their actual water use for the prior year, under penalty of perjury, when they renew their local business licenses. Utah requires new large data centers to report annual water withdrawals to the state, which publishes them, but existing and smaller facilities are exempt. In Virginia, water suppliers will report monthly volumes delivered to data centers, effective Jan. 1, 2027.

Texas requires data centers to report water use, but few do. Of 334 data centers in Texas Water Development Board records from 2020 through 2025, obtained by The Texas Tribune, 233 have never submitted the board’s mandatory water-use survey. Failing to respond is a Class C misdemeanor, punishable by a fine of up to $500. The state’s utility commission also ran a voluntary survey, which fewer than a third of the companies it contacted answered. The attorney general opened an investigation on Sept. 24 that will cover hundreds of projects across at least 18 counties. On Oct. 15, the office sent letters to 156 data center developments demanding “up-to-date and accurate information” about their water use.

On the federal level, Rep. Rob Menendez (D-N.J.) and Rep. Greg Casar (D-Texas) introduced the Data Center Transparency Act on Jan. 8. The bill would require the EPA to report to Congress at least every three months on how much water U.S. data centers consume, how much they reuse and how they affect local water systems, and to post those reports publicly online. It has sat in the House Energy and Commerce Committee since it was referred that day.

Even where states require reporting, the authors noted, “the situation evolves quickly and actual water consumption can differ substantially from design specifications.”

New Jersey’s first reports, from data centers that have operated for at least a year, are due in late November.