One data centre in Ireland used enough water for 18,000 people in a single year — and no planning authority required it to say so

Meta's data centre in Clonee, County Meath, withdrew 928 million litres of water in 2021 — equivalent to the annual domestic water use of 18,560 people. Planning authorities in Ireland, England, Scotland, and across the European Union approved that facility and hundreds like it without any systematic requirement to disclose how much water the site would use, when it would use it, or what the cumulative effect on local catchments would be in dry periods.

New research published today by The Firewalkers, examining data centre water consumption across the UK, Ireland and European Union, finds that this is not an isolated case. It is a systemic gap. The planning systems processing applications for facilities that can consume millions of litres a day have no common obligation to require site-level disclosure of annual withdrawal, peak-day demand, potable water use, or cooling system configuration.

The gap between a national average and a local crisis

Ireland's national water utility, Uisce Éireann, has said that data centres account for less than 0.2% of national demand. That statement is true and misleading at the same time. The same utility manages large data centre users by limiting peak flows and requiring private storage — because the question is not the national share, it is what happens to a city-region dependent on a single river when peak demand spikes in a heatwave.

The greater Dublin area draws 85% of its supply from the River Liffey. A facility that is nationally small can still be locally significant when drought reduces that river's flow and every large user draws simultaneously.

England's data tells the same story at regional scale. The Environment Agency's 2025 national water resources assessment found that 57% of England's data centres are in the south-east, that 38 of the top 50 water-consuming facilities are concentrated in that region, and that consumption peaks in summer in line with temperature. Those are not coincidental findings. They describe a structural collision between data centre growth and the most water-stressed part of the country.

AI changes the question — but not simply

The research finds that artificial intelligence makes the water question harder to answer, not easier. Higher computing density from AI workloads generates more heat and more pressure on cooling systems. Google has said directly that the expansion of AI products and services increased its data centre water footprint.

Yet the same technology can also reduce direct water use where it drives adoption of closed-loop or liquid-to-chip cooling systems. Microsoft says its new AI-ready facilities in Spain are designed to consume zero water for cooling. Google's Dublin campus, as noted above, uses just 2.7 million litres a year after switching to air cooling — compared with 928 million litres at Meta's Irish campus in its peak year.

Five regions — five different versions of the same failure

The regulatory gap — disclosure without accountability

The research acknowledges that the EU regulatory framework is improving. The recast Energy Efficiency Directive and the 2024 delegated regulation now require large data centres to publicly report total water input and potable water input. The European Sustainability Reporting Standards (ESRS E3) require disclosure of material water risks. The European Commission itself noted in 2026 that, beyond transparency, the current framework does not set incentives for operators to improve sustainability performance.

These are frameworks for disclosure. They are not frameworks for allocation. They do not answer the question a resident, a farmer, or a river catchment manager needs answered: in a drought, who gets the water first, and who decides?

The Environment Agency put the problem plainly in its own assessment: future non-household demand forecasts are unlikely to capture future data centre needs because growth is too rapid and too little is known about where sites will be built and what cooling methods they will use. That is the core policy gap, stated by the regulator responsible for managing the water.

What The Firewalkers is calling for

The Firewalkers is calling on planning authorities in the UK, Ireland and across the EU to require mandatory site-level water disclosure for all large data centres, covering annual withdrawal, annual consumption, potable water input, non-potable water input, peak-day demand, and cooling system configuration. This information must be publicly available at development and operational stages, not only in corporate sustainability reports.

Planning and abstraction regimes should require catchment-level cumulative assessment for clustered data centre development — not only site-by-site review. This must include drought and heatwave scenarios and must be published before consent is granted.

Where potable supply is proposed, applicants should be required to demonstrate why lower-water alternatives — reclaimed water, rainwater capture, seawater where relevant, or air-cooled architectures — are not feasible. Google, Microsoft and Amazon all publicly advance these practices in some locations. They should become planning requirements, not voluntary claims.