Water UK warns ministers: data centers were left out of the water forecast

Britain's water companies are planning the next five years against supply limits drawn up for an economy that, on paper, excludes the data centers the government now wants to triple by 2030. That contradiction is the warning the water-utility trade body Water UK put on the record this month in its "Barriers to Project Delivery" report and in a submission to a parliamentary inquiry, with three policy options attached.

UK data centers currently use about 6.6 million litres of water a day, roughly the demand of 20,000 households, according to Water UK. In the warmest weeks, when cooling systems work hardest, that figure climbs to around 14 million litres a day, more than double the average. If ministers deliver on the 2030 trebling target, peak demand would rise to about 42 million litres a day, equivalent to a further 40,000 homes' worth of water drawn from the same rivers and reservoirs.

The planning architecture was never asked to count data centers at all. England's National Framework for Water Resources, the Environment Agency document that sets the ceiling on how much water companies can abstract from rivers, reservoirs, and groundwater, was published in 2025 with data center demand explicitly excluded. The five-year Water Resources Management Plans that individual water companies then submit to Ofwat are anchored to that framework and were locked in for the 2025-2030 period, so the supply limits they are set against are structurally wrong for the 2030 mix. Ministers are also guiding water companies to model a future in which business water demand will fall over the same window, inverting the trajectory the data center push implies. Reopening the framework mid-cycle is one lever ministers have; a new round of company plans is the cleanest place to add data center demand to the baseline.

Data centers are not the only sector left out of the framework. The same forecasts exclude gigafactories, the large EV-battery and industrial plants also in the government's growth plan, on the same structural basis. If both sectors scale to their 2030 ambitions, the abstraction gap widens on two fronts at once.

Water UK has put three options to ministers. The trade body wants a temporary lift to the cap on how much water companies can take from rivers, reservoirs, and groundwater, a process the trade calls abstraction, while new sources are explored and funded. It wants developers, including data center operators, to be allowed to fund new supply directly. It wants a tougher water-efficiency standard applied to data center projects. The third lever does not depend on the next reservoir; the first buys time for one.

The same planning gap also threatens more than a million new homes, according to Water UK's submission to the Environmental Audit Committee (written evidence 164766). The phrase "explicitly excluded" is Water UK's own, picked up by The Guardian's coverage of the warning, Envirotec's trade-press write-up, and Water Briefing's note, which put the same numbers on the public record this week.

The second-order question is what happens if water becomes the binding constraint. The Register's analysis of the AI-superpower plan points to the credible threat: hyperscale operators that have made the UK a default European hub can site new capacity in lower-stress markets in Ireland or the Nordics if the supply ceiling stays where it is. The trade body's own prescription, a binding efficiency standard, is the lever that does not depend on the next reservoir. The question ministers now face is whether to reopen the National Framework or to keep patching a baseline that already excludes the sector ministers want to triple.