The UK will not have enough water for future datacentres, the water industry has said in stark criticism of the government’s AI growth plans. Datacentres rely on large amounts of water to manage the heat generated by densely packed servers. Cooling towers, chillers and humidification systems make direct use of this water, with large volumes also consumed indirectly through high electrical power needs.

Water UK, the trade body that represents water companies in Britain and Northern Ireland, said in a publicly available written briefing to MPs that the government’s water forecasts were “fatally flawed” and “explicitly exclude” datacentres. It wrote that the government “makes not a single mention of water” in its policy for delivering AI growth zones, its AI for science strategy or its AI opportunities action plan. It added that the Environment Agency’s most recent national framework for water resources, published in June 2025, also failed to include an estimate of the water demands of datacentres.

“There appears to be an assumption that the country will always have enough water for its economic needs,” the briefing said. “Nothing could be further from the truth.” In May, a House of Lords report said England faced a 5bn litre a day shortfall for public water supplies by 2055. Water UK said datacentres were already being built in water-stressed areas, with more than three-quarters located in the south and east of England.

Millions of people in these regions have been placed under a hosepipe ban by water companies after prolonged extreme heat and lack of rainfall. The trade body said any new datacentre growth in these areas “may be impossible” without policy change because of existing pressure on the network. “As leakage and demand targets are already very ambitious, the only solution to deliver new supply is to increase the amount of water taken from the environment – which may be harmful – or to build new supplies, and major reservoirs can take 15 years to plan and build,” Water UK wrote.

It added: “Water companies have cut leakage by around 40% since privatisation and plan to reduce it by a further 17% by 2030.” However, Greenpeace said last week that water companies were wasting five times more water through leaky pipes than even a national hosepipe ban would save. The UK’s highest concentration of datacentres is in Slough, which is served by Affinity Water. About 125 datacentres are proposed or under construction in Affinity’s region, much of which is subject to a hosepipe ban.

In May, the company told MPs that some of these datacentres were requesting up to 3m litres of water a day, equivalent to the peak water demand of 3,500 homes. “The planning framework is built around household growth and per-capita consumption, and has not adapted to commercial users whose water needs can match those of a market town,” Affinity said in a written submission to the environmental audit select committee. Because of Environment Agency permitting, datacentres are currently required to make use of drinking water only.

Water UK estimated that datacentres in England use 6.6m litres of drinking water every day.