A new report into potable water use by data centres in the UK has called for mandatory, centralised reporting and clearer benchmarking, as public concern grows about whether rapid AI-driven expansion is being properly accounted for in water planning.
The study, delivered by the Water Research Centre (WRc) and funded via the Strategic Panel’s Market Improvement Fund (MIF), argues that evidence gaps and inconsistent data make it harder for water companies, regulators and planners to assess how the sector is changing – and where local pressures could emerge. It recommends policy options including a reporting framework covering water use and water efficiency, stronger engagement between developers and water companies at the planning stage, and reducing barriers to using non-potable alternatives for cooling, such as treated sewage effluent.
Rick Hill, Independent Panel Member from the Strategic Panel, commented, “Investigating data centres is essential to fill major evidence gaps on their potable water use and rising demand. The Strategic Panel funded this work to inform policy and support sustainable sector growth. The report will guide planning, benchmarking and regulatory development to manage future water impacts effectively.”
A small number of sites account for most consumption
WRc Head of Water Efficiency Joe Cahill said current data centre potable water consumption in England is estimated at 1,879,000 m³/year – around 0.2% of the non-household market – and is trending upwards.
He noted, “A headline finding was that, while some English data centres can consume fairly large volumes of potable water, this is not the norm and the landscape is significantly different from other jurisdictions, notably the United States, where evaporative water cooling (such as using cooling towers) is commonplace. This is largely due to differences in environmental laws and the predominant use of groundwater, whereas in the UK there is often little value in exploring unless you’re energy- or space-constrained, or running high-density equipment such as AI.
“Our analysis has found that the majority of data centres do not consume significant quantities of potable water (67% use <1000 m3/year). This consumption is highly skewed towards the large water users, with the top six data centres accounting for 65% of the sector’s water consumption. Many of these appear to have come online in the last few years.”
The report’s warning is not simply about annual volumes. Joe added, “Rather the larger concern is demand on peak days, and that these would likely coincide with increased domestic demand, as both have temperature as a significant driver.”
That backdrop has become harder to ignore after England’s 2025 drought, with the Government warning the country cannot “take water for granted” as pressure on supplies grows.
How the UK could learn from the European Union
WRc’s call for better transparency lands as the EU moves to formalise reporting obligations for data centres. Under the recast Energy Efficiency Directive (EU/2023/1791) and the Commission’s delegated regulation establishing a common rating scheme, operators must report key performance indicators into a European database which publishes information relevant to both energy performance and water footprint.
The Commission says the reporting scheme is intended to increase transparency and drive more efficient designs that can reduce energy and water consumption, promote renewable energy use and support waste heat reuse. WRc recommends that the UK Government considers a similar direction – including mandatory reporting of at least a subset of the metrics required under EU rules – to enable more meaningful benchmarking between sites.
UK debate hardens as AI growth accelerates
In the UK, the water question is becoming increasingly politicised. Recent reporting has highlighted growing opposition to hyperscale developments, with campaigners arguing that new AI data centres risk adding to local water stress as well as pushing up power demand.
At the same time, industry groups have pushed back against claims that UK facilities are inherently water-intensive. A techUK report, based on a joint survey with the Environment Agency covering 73 commercial data centre sites, found 51% used waterless cooling and 64% consumed under 10,000 m³ of water per year, with only 4% reporting usage above 100,000 m³ annually.
