Data centers cost an incredible amount of money to build, and require equally eye-watering amounts of electricity to power them. But while companies might talk up their green credentials through improved hardware efficiency or renewable energy, one area that's often overlooked in their design and construction is the astronomical quantities of water they consume. This year's enormous scale of datacenter and "AI factory" announcements doesn't just raise concerns about their electricity use and environmental impact, but also about the unprecedented amount of water they'll consume just to keep these facilities cool.
A single data center can consume upwards of five million gallons of water per day, or enough for a small town of 50,000 people, says the Environmental and Energy Study Institute. If you scale that problem up nationwide, the issue becomes even more exacerbated. In 2024, it was estimated that U.S. data centres consumed over 60 billion gallons of water through cooling; the figure provided by the Lawrence Berkley National Laboratory also excludes the quantities of water used for electricity generation or on-site needs outside of cooling.
This is magnified in hotter parts of the country, where water is both rarer and in greater demand. Hotter ambient temperatures mean more water is required for cooling, and with consistent demands to keep operating costs and carbon emissions low, there's greater emphasis on using cooling techniques like evaporative cooling, which minimizes electricity use, even at the cost of greater water use. This is of particular importance, as supplies are being squeezed while companies scramble to scale up.
Moreover, local communities are incredibly reliant on clean local water supplies. Data centers not only compete for water access but have also been linked to poor water quality, though the companies operating them might deny the claims.
Cooling is hard
Cooling is crucial for data centers, as it affects performance and operational costs. Typically, this is handled in one of two ways: open-loop and closed-loop cooling. In an open loop, hot air from the data center is blown over water-moistened pads, or it's sprayed into the air in a fine mist. As the water evaporates, it reduces the temperature of the air, but that water is lost from the local water table completely, making it much more wasteful in its water use.
Closed-loop liquid cooling cools components directly via water blocks and loops, or by immersing the hardware in the cooling liquid. In either case, electric chillers are used to reduce the temperature of the water once it's been heated. This technique doesn't evaporate much, so water use is reduced, though electricity use and costs are typically far higher.
Of course, companies are also looking into exotic cooling methods, such as direct-to-chip and immersion cooling, which can also affect the amount of water being used in such cases.
Quantifying the issue
(Image credit: Nvidia)
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