Companies that run data centers are facing increasing scrutiny for guzzling water as the rise of artificial intelligence and massive investment in cloud computing drive a construction boom. The centers, which generate lots of heat, can require huge amounts of water to cool their servers and interiors.
Yet, while water needs soar, many companies do not disclose how much they use.
Google, for one, does list water data for three dozen data centers around the world in its latest annual environmental report, saying a single site can use more than 3 million gallons per day, with some using far less, depending on cooling design and size. But most of the data centers in the report were not in the dry western United States, where much of the industry’s build-out is happening, and where water is already under stress.
California legislators are taking an initial step toward tackling the water problem by requiring data centers to report their water use annually. The legislation, approved this month, is now awaiting Gov. Gavin Newsom’s signature.
“Data centers are popping up all over the place,” said Assemblymember Diane Papan (D-San Mateo), the bill’s author. “And they demand so much water.”
If Newsom signs the bill, California would be among the first states to require water disclosure. New Jersey also has a bill before Gov. Phil Murphy, and similar legislation has been introduced in New York. In Arizona, the state has long required water information from large-scale facilities including data centers in urban areas, and they have to meet water efficiency standards as well.
“It’s very important that localities be able to plan for what’s next, whether that’s building more housing or building data centers,” said Papan, who chairs the Assembly Water, Parks and Wildlife Committee.
Much of the nation’s data center construction boom is taking place in arid states, including California, Arizona and Texas, where strains on water have been mounting amid dry conditions and rising temperatures.
The ongoing water shortage on the Colorado River, where reservoirs are approaching critically low levels, is expected to force additional reductions in water use in the Southwest in the coming years.
A key goal is to prevent problems, Papan said, “so that we don’t end up with a data center without sufficient water, and we don’t end up with a community that has a data center that takes too much water away from the community.”
Assembly Bill 93 was opposed by business groups including the Data Center Coalition. Newsom has until Oct. 12 to sign or veto it.
In a report released this week, researchers with the nonprofit group Ceres analyzed current and projected water use for data centers in the Phoenix area, where, as of May, there were 75 of the facilities and 49 more planned. It found that water for cooling, as well as water linked to the massive electricity they need, is expected to dramatically increase in the coming years as more facilities come online.
The group projected that cooling water alone in the Phoenix area could increase to more than 3.7 billion gallons per year, enough to supply a city of about 80,000 people for nearly two years — a change it said could increase water stress in a region that is already grappling with scarcity.
“This needs to become a consideration in those areas,” said Kirsten James, senior director of Ceres’ water program. “If companies and their shareholders do not address these sustainability risks, then that could leave them open for financial loss, and so they really need to be proactive.”
Experts say California has more than 300 data centers, with many more planned.
Some major tech companies already disclose their data centers’ water use in other parts of the country, so it makes sense for California to collect this information, especially since the state is known for both leading on innovation and for having long droughts, said Shaolei Ren, an associate professor at UC Riverside who studies data centers’ use of resources.
“We ask California residents to switch to artificial turf and display ‘water conservation’ stickers in public places, yet data center water use remains hidden,” Ren said. “Disclosure doesn’t hurt the industry or add costs; it simply helps us track and manage a vital resource more responsibly as we build the next generation of data centers.”
The International Energy Agency said in a recent report that a 100-megawatt data center in the U.S. can consume approximately 500,000 gallons of water per day. But it said innovations in cooling systems can significantly reduce that.
Most data centers have systems that circulate either liquid or air for cooling. Many have industrial-scale cooling towers where water evaporates and helps cool interior space.
There is huge variation in water use. Facilities with closed-loop dry coolers may use virtually no water on-site, while those that rely on evaporative cooling are more water-intensive, Ren said.
Notably, the types of systems that require little water are generally more energy-intensive and costlier, Ren said.
In its report, Google said some of its more water-intensive centers, including two in Iowa and Oklahoma, require five to six times as much water as an average golf course, while various other facilities use less than a typical golf course. None of the data centers the company listed are in California.
Google said it is focused on “advancing responsible water use,” and that last year, 72% of its water “came from sources at low risk of water depletion or scarcity.”
Michael Kiparsky, director of the Wheeler Water Institute at the UC Berkeley School of Law, said requiring data on water use is a good first step, but that information alone would not help local officials determine if there is a more conserving option or another location with more water available.