Water and Datacenters: WUE, the Next Frontier of Digital Investment in Europe

After electricity, water. An evaporative-cooled datacenter can consume as much water as a town of 10,000 people. In Spain and Italy, where drought is becoming structural, this consumption is reshaping permits — and soon valuations.

A few benchmarks. One IT megawatt cooled by evaporative towers absorbs 25 to 30 million litres per year. Since 2024, the EED directive has required datacenters above 500 kW to report their WUE — water usage effectiveness, the litres consumed per IT kilowatt-hour. Like PUE ten years ago, the metric is stepping out of the shadows.

The field is ahead of regulation. In Aragon, local opposition imposed a water cap on a hyperscale project. In Catalonia as in Castile, public-interest reviews now examine the water plan alongside the grid connection. In the Netherlands, permits have been suspended for this reason alone.

Technologies That Cut Consumption

Direct-to-chip liquid cooling changes the equation: heat leaves in a closed water loop, with no evaporation. A 100 kW GPU rack cooled by liquid consumes 80 to 90% less water than an equivalent evaporative hall. Adiabatic systems use water only a few hundred hours per year, on the hottest days.

Geography remains a technology choice. Nordic free cooling runs on air almost year-round; in southern Spain or Italy, only closed loops and liquid cooling can hold WUE below 0.2 litres per kilowatt-hour — the threshold municipalities are starting to demand.

What This Changes for Investors

WUE enters due diligence alongside PUE. An evaporative site in a water-stressed area carries three cumulative risks: permit refusal for expansion, renegotiated abstraction rights during droughts, and compliance retrofit costs. These risks can be priced — and are starting to show up in discounts.

Conversely, a closed-loop or liquid-cooled asset earns a double premium: immediate local acceptance and compatibility with GPU densities, which require liquid cooling anyway. The water constraint and the density constraint are solved by the same technology — it is rare for one investment to fix two problems at once.

How We Apply This at FINXIA

In the TITAN DC AI strategy, the initial review now includes a water score: watershed, twenty-year drought history, installed cooling technology and target WUE after transformation. In Spain and Italy, the absence of a credible water plan has become an eliminatory criterion.

Our brown transformations integrate liquid cooling from the design stage. The extra cost is real — around 10 to 15% of the technical budget — but it secures the permit, the density and the exit. On an asset held for ten years, it is the best calculation in the file.

Key Takeaways

Water joins electricity as a structural constraint on the European datacenter. EED, droughts, local requirements: WUE will be in every data room within two years.

Worth watching: the first binding WUE thresholds in Spain and the Netherlands, and the appearance of a water-plan line in building permits for campuses above 50 MW.