Data centres are popping up everywhere. Will they drink up all our water, too?

Cow sheds and data centres have a lot in common, and Texas has plenty of both. Squat, utilitarian structures, neither tend to win architectural prizes, much less the doting affection of their neighbours. They’re also capable of consuming vast amounts of water, either to quench the thirst of the herd or, much more commonly in the case of the data centre, to cool humming server racks as they crunch through the billions of data points that underpin our digital economy. 

But where cow sheds have dotted the Texan landscape for centuries, the data centre has proven to be a more controversial innovation. Though water demands among livestock farmers have been historically high – one study concluded that livestock production accounts for almost a quarter of humanity’s water usage – residents in bone-dry counties have found new data centre announcements altogether more unnerving. “I try my best to conserve water because I know we’ve been in a drought for years. I take quick showers, turn off the faucet when I brush my teeth and wash my hands and reuse water for my plants,” said Sloan Rucker, a life sciences consultant protesting a new data centre development outside San Marcos. “None of these little efforts will mean anything if we let data centres into this area… data centres require tons of water that we don’t have.”

That protest, as it turned out, was successful. But more facilities are likely coming to Texas and a water-stressed region near you. In Spain’s Aragon region, also in drought, Amazon plans to double a data centre footprint that already sucks up 755,720 cubic metres of water per year. The company has additionally requested permission to increase that water consumption in its current centres by 48%, while those new sites are predicted to consume more electricity as the entire region itself currently uses. Back in Texas, HARC estimates that, by the end of 2025, data centres could gulp down 49bn gallons of water, rising to 399bn gallons by 2030 to account for 6.6% of the state’s total water usage. 

Big Tech bosses like OpenAI’s CEO Sam Altman have pushed back on the focus on AI’s data centre water use (“I particularly love when the anti-AI crowd makes up shit about our water usage while eating a hamburger”, he recently tweeted). That’s easy to do when, like many LLM developers, OpenAI keeps its energy usage figures mostly private. The fact that these companies are enamoured with a business model underpinned by resource-guzzling scaling laws means that their water usage is only going to increase, argues Erin Kinney, a senior research scientist at the Houston Advanced Research Centre (HARC). “It’s that increase when we already have a huge need,” says Kinney, “that’s really creating a problem.”

Data centre water usage in the UK

Might the UK go the way of Texas? The number of data centres in the former is set to go up by a fifth, according to recent figures, with the incumbent Labour government encouraging further expansion as a means of boosting economic productivity. While the UK experiences drought conditions less regularly than Texas or Aragon, the prospect of more server barns popping up in the Cotswolds or Cumbria has begun to worry sections of the water industry, with the Environment Agency unable to determine how many litres the country may be short of by 2055 and the National Drought Group calling for the public to delete their old photos and emails to ensure servers don’t dry up reservoirs. 

These warnings are overblown, argues Luisa Cardani, the head of techUK’s data centres program. While a recent series of heatwaves may have made Britons feel like they’re suddenly living in the Texas Hill Country, the industry body’s latest survey of UK data centres suggests that high water usage at most facilities is not occurring, with 51% of respondents using waterless cooling systems. 64% of sites, meanwhile, use less than 10,000m3 of water a year – similar to a Premier League Football Club. 

For her part, Cardani believes the sector has been “misunderstood”, modest as it is about its environmental credentials or, as it happens, about promoting any of its achievements in the media. As she explains it, there was a shift among data centres from air- to water-cooled systems in the 2010s to offset electrical emissions and avoid the high cost of energy in the UK. Since the effects of climate change have become clearer, however, many data centres have “proactively” reversed course, says Cardani, with the report showing that “most of them are moving towards waterless or hybrid systems.”

The report has its limitations: it is a voluntary survey, opening the results up to self-selection bias, and is limited mostly to wholesale data centres rather than on-premises or enterprise sites. That includes some of the thirstiest sites, like the hyperscale sites that can consume from 4-19 million litres of water a day. Professor Adam Sobey, mission director for sustainability at the Alan Turing Institute, says that while he isn’t aware of specific areas that have come under water pressure from data centres in the UK, the country’s recent water shortages mean there is no room for complacency.

“As we go to build more data centres, then that’s going to put more pressure [on the water network] – especially in areas near drought levels,” says Sobey. He argues that even though the average AI user isn’t causing huge amounts of additional water usage through data centres, sectoral demand will increase as AI grows more popular in the coming years. 

“Lots of people doing it in small amounts in a system that is already under pressure over time creates more problems,” says Sobey. “The model sizes are getting bigger and, as they do, you have to use more energy to train and use them. As you move forward even five years, that becomes more of a challenge.”

Recent research from techUK suggests that data centre water usage in Britain is not nearly as high as previously thought. (Photo: PongMoji / Shutterstock)

Alternatives to water-cooled data centres

Taking on the AI age sustainably will mean data centres finding new and innovative ways to keep servers cool while using as little water as possible. For its part, Microsoft is championing waterless cooling methods in its newest data centres, a trend that Martina Raveni, a strategic intelligence analyst at Global Data, calls the “next frontier” for the industry. Data centres can phase out water cooling for immersion cooling, or submerge servers in dielectric fluid to prevent overheating. If they’re feeling more sophisticated, direct-to-chip (DLC) cooling, which involves passing dielectric fluid through cold plates directly onto chips to absorb their heat, is another option. It is those liquid cooling methods, in a hybrid mix with water and air cooling, that the “industry as a whole is transitioning towards,” says Raveni. 

Outside of data centre technology itself, the water sector itself could be more proactive about managing future demand, argues Cardani, who calls on the government to explore options to maximise water efficiency in the UK. Considering almost a trillion litres of water were lost to leaks in England and Wales in 2024, she thinks that “perhaps water has not been managed as efficiently as it could have.”  

And while Cardani pushes back on the idea that data centres have been avoiding releasing official figures of their water use, she argues that more transparency in measuring and publishing such data could benefit the sector. But it’s going to take tough decisions from everybody to cut down on water usage, concludes Sobey. He calls for individuals to be cognisant of the water usage of their daily searches, such as the difference in water consumption in streaming a music video versus simply listening to a song’s audio. 

“If we want to use more AI, we have to reduce things elsewhere, and I just don’t think that’s happening,” he says. “We are using more energy and water all the time on everything – and we can’t really afford to do that.”

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