UK data centre boom hits a water reality check

Britain wants to triple its data centre capacity by 2030, but Water UK says the country has not planned for the water those facilities will need. In evidence to MPs this week, the trade body for England’s water suppliers argued that ministers' growth plans barely account for data centre demand, even as major projects face delays and costs mount.

Today, data centres in England use about 6.6 million litres of drinking water a day. If capacity triples as planned, Water UK expects that to rise to 19.8 million litres a day.

The pressure is highly concentrated. In the Affinity Water region, some proposed sites have asked for as much as 3 million litres a day — about the daily use of 3,500 homes. Around 125 data centres are proposed or under construction in Affinity Water’s territory, which includes Slough, and more than three-quarters of the UK’s data centres are in the already water-stressed south and east of England.

That region is already drawing roughly 220 million litres a day more than water companies had forecast, before most planned data centres are even built. In some places, the gap between supply and existing demand has shrunk to about 2%.

Water planning rules leave data centres largely untouched

Water UK’s main complaint is that data centres are mostly missing from England’s water planning framework. The group told MPs that data centres are excluded from the Environment Agency’s national water resources framework, while the government’s AI growth zone policy does not mention water at all.

Recommended reading

Only 34% trust AI agents despite 86% deploying them

“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.”

Because ministers have designated data centres as critical national infrastructure, water companies say they have limited ability to curb usage when supplies tighten. During the hosepipe bans that spread across the south and east this summer, restrictions applied to households, while data centres continued drawing on drinking-quality water under current rules.

David Henderson, Water UK’s chief executive, said the problem is as much about planning as rainfall.

“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 Water UK’s figures, current supply can support only about 420,000 of the 1.5 million homes the government wants built.

Reservoir delays and cooling technology

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, although about 60% of that could be closed through leak repairs and lower demand. Water UK says those projections still do not fully account for data centre growth.

The group wants data centre demand included in national planning assumptions, alongside faster approval for reservoirs and other large water projects. The sector is also trying technical fixes, including closed-loop and air-based cooling systems that use far less water than evaporative cooling, while some operators are attempting to recycle waste heat.

The government has earmarked nine new reservoirs and says its AI growth zones are being placed where energy and water are already available. But the national policy statement meant to define that expansion was due in February and still has not appeared.