Britain wants to triple its data centre capacity by 2030. The trade body for the country’s water companies has told ministers there is not enough water to run them.
Water UK, which represents England’s water suppliers, told MPs this week that the government’s growth agenda barely accounts for what those machines will drink.
Data centres are all but absent from the frameworks that ration England’s water, even as marquee projects such as Stargate UK stall over cost and newer sites run into grid delays of their own.
The numbers are small today and steep tomorrow. Data centres in England use about 6.6 million litres of drinking water a day, and Water UK expects that to reach 19.8 million litres if capacity triples as planned.
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Individual sites already ask for more than their neighbours: in the Affinity Water region, some proposed centres have requested up to 3 million litres a day, roughly the daily consumption of 3,500 homes.
The strain is concentrated rather than spread. Around 125 data centres are proposed or under construction in Affinity Water’s territory alone, which takes in Slough and its dense cluster of server halls, and more than three-quarters of the UK’s data centres sit in the water-stressed south and east of England.
The same corner of the country already draws roughly 220 million litres a day more than water companies had forecast, before most of the pipeline is even built. In some areas the margin between what suppliers can deliver and what customers already use has narrowed to about 2%.
Because ministers have designated data centres as critical national infrastructure, water companies say they have little power to turn the taps down when supplies tighten.
During the hosepipe bans that spread across the south and east this summer, the restrictions fell on households rather than on data centres, which under current rules draw on drinking-quality supplies.
Water UK’s central complaint is that none of this has been counted. Data centres are excluded from the Environment Agency’s national water resources framework, and the body told MPs that the government’s AI growth zone policy makes no mention of water at all.
“There appears to be an assumption that the country will always have enough water for its economic needs,” its briefing said. “Nothing could be further from the truth.”
David Henderson, Water UK’s chief executive, cast the problem as a planning bottleneck rather than a shortage of rain.
“We desperately want to be able to provide enough water for new housing,” he said, “but are being held back by a regulatory system that makes building new reservoirs much slower than it should be.”
On the body’s own figures, current supply can serve only about 420,000 of the 1.5 million homes the government wants built.
The backdrop is a widening gap between what England has and what it expects to need.
A House of Lords report in May projected a public water shortfall of around 5 billion litres a day by the middle of the century without intervention, though roughly 60% of that could be closed through leak repair and lower demand.
Those projections do not fully reckon with data centre growth, which is precisely the omission Water UK is trying to force onto the page.
Water UK wants data centre demand written into national planning assumptions, and faster approval for reservoirs and other large water projects.
The industry is also leaning on engineering, with closed-loop and air-based cooling systems that use far less than evaporative methods, and a handful of operators trying to recycle waste heat rather than pour it away.
The government has earmarked nine new reservoirs and says its AI growth zones sit where energy and water are already available.
A national policy statement meant to set the terms for that expansion was due in February and has yet to appear. Until it does, the country is committing to the data centres before it has settled where the water will come from.
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