Booming demand for artificial intelligence tools, accelerated by the uptake of generative AI, is putting an increasing strain on water supplies to cool the IT infrastructure underpinning the technology. Now, the companies operating these data centres are facing calls to make the facilities much more efficient and subject to greater regulation.
In the US, Virginia state legislators have advanced a bill aimed at addressing data centres’ water use. The bill would authorise municipalities to require centres to submit water use estimates as part of building requirements. Virginia is currently home to one of the world’s biggest concentrations of data centres, used by companies such as Amazon, Google and Microsoft.
The bill, which is waiting for approval or veto from governor Glenn Youngkin, reflects voters’ concerns about data centres draining local water resources. The Virginia Conservation Network, an environmental non-profit organisation, argued in February that the state of Virginia has no regulatory oversight of data centre development and that it should collect more information about their water usage in order to plan better.
“A major tech company’s data centres can consume many billions of litres of water annually, in some cases rivalling the water consumption of major beverage companies,” says Shaolei Ren, an associate professor in electrical and computer engineering at the University of California Riverside. He estimates that global demand for AI processing will consume 4.2bn-6.6bn cubic metres of water abstracted from ground or surface sources in 2027.
4.2bn-6.6bn cubic metresEstimated abstraction of water needed globally for AI processing in 2027
Public anxiety about who is using water and for what purpose has grown since drought conditions affected Virginia and other parts of the US in 2024. Nearly every US state experienced abnormally dry conditions, according to the National Oceanic and Atmospheric Administration, the US climate agency.
Longer and exceptional droughts in the US pose risks of operational disruption to data centres, investment bank Jefferies said in a report last year.
Legislation, or the threat of it, and public concern about water use, has prompted some companies to take action. At Equinix, a big US data centre operator, water availability has been taken into account when deciding site locations.
The company says its data centres’ water use in 2023 was similar to that of a small US town annually. About 60 per cent of that water evaporated and 40 per cent went into the local wastewater system.
“We’re constantly monitoring what’s happening from a regulatory perspective,” says Christopher Wellise, vice-president of sustainability at Equinix. Cooling techniques at its facilities include keeping more of the water in a closed loop.
“If you shift from traditional evaporative cooling to closed-loop cooling, you’re going to significantly reduce the need for water,” he explains. Evaporative cooling runs cold water between overheating materials and discharges the steam into open air. But in a closed-loop system, the water stays within the structure for reuse.
More stories from this report
The rise of AI has intensified the calls for action. Data centres that handle AI workloads do more intense processing and require six to 10 times more power than conventional data centres of similar size, says Noman Bashir, an expert in computing and climate impact at Massachusetts Institute of Technology’s Climate and Sustainability Consortium, an industry and academia collaboration.
He also notes that efforts to use cooling mixtures as an alternative to water are fading because the liquids used “have been found to be very toxic” — which means a return to water.
In August 2024, Microsoft announced a new design for data centres that would involve losing no water to evaporation when used for cooling. The tech company could save more than 125mn litres of water per year per facility, it said.
The search may be on for water-saving technologies, but “relying on innovation alone to solve this challenge is not necessarily enough, at least in the short run”, says Christelle Khalaf, associate director of the government finance research centre at the University of Illinois in Chicago. That means governments stepping in, she argues, with regulation and siting guidelines to direct new data centres to places where water resources are less scarce.
“As more facilities are built, they risk competing with communities, agriculture, and industry for limited water resources,” UC Riverside’s Ren says. “Even data centres with relatively low average water use can strain local infrastructure due to their high peak water demand.”
Some data centre operators are already looking for locations with more reliable water supplies. One Equinix data centre in Toronto, for instance, pulls cold water from deep in Lake Ontario, which it says has cut the facility’s energy needs by half without increasing water consumption.
