Milan hosts roughly 200 MW of data-centre capacity today. A2A chief executive Renato Mazzoncini estimates the city could add about 2 GW within five years, nearly a tenfold jump, and the facilities being built to meet that demand are designed to draw almost no mains water. Retelit broke ground in May 2026 on a 13.6 MW AI-ready campus in Corsico, southwest of Milan, built around a sealed closed-loop cooling system with heat recovery for nearby homes. In Italy, the debate over artificial intelligence and water has moved past the frightening-number stage. For those financing essential infrastructure, the open question is no longer how much water AI consumes, but whether water availability now conditions whether facilities get built at all, and who pays for the engineering that removes the constraint.
First pillar: the build side is already designed around water, and the reference projects are Italian
Retelit's Corsico campus covers 18,000 square metres across two identical buildings and uses a closed-loop water system specifically to protect the local water table, combined with liquid cooling for high-density AI racks. Its waste heat is intended to warm around 1,250 nearby homes, with first capacity planned for 2027 (company-stated specifications). A2A, Lombardy's largest utility, already operates what it describes as Italy's first liquid-cooled data centre connected to a district-heating network, running in Brescia since June 2025 and able to recover heat up to 65 degrees. Mazzoncini has said the Brescia model can be replicated in Milan, where waste heat from the new facilities could serve more than 150,000 homes, and many more in a full-build scenario. These are engineering choices written into the facility, not sustainability language added afterwards, and they now define what a financeable Italian data centre looks like.
Second pillar: water availability has become a siting criterion, and Italy is handling it differently from the United States
Lombardy already has more than 60 data centres operating or in the authorisation pipeline, so the load on grids and permits is a concrete planning issue, not a hypothesis. In the United States, reporting indicates that around two-thirds of the 809 planned AI data centres will be sited in areas of severe drought, with sector water demand estimated to grow toward 73 billion gallons a year by 2028. That siting pattern has produced a political backlash and a proposed federal moratorium on facilities above 20 MW. The Italian cluster, by contrast, is being steered toward closed-loop reuse, non-potable sourcing and heat recovery before the permitting fight begins, turning a water risk into a capex line. The contrast tells capital allocators where the engineering spend falls, and why the Italian build-out is more investable than the headline fear suggests.
Third pillar: the money to make this build-out water-proof comes from tariffs, reused water and private balance sheets
Italy's regulated water system now plans more than 29 billion euros of investment through 2029 under ARERA's methods, and on 6 October the regulator signalled that it will set tariffs ex officio for operators that missed the MTI-4 update deadline. Reuse is the second lever. Europe recycles only around 2 per cent of its treated wastewater and Italy under 5 per cent, against an EU average of about 17 per cent, so non-potable water for cooling is an under-used resource sitting right next to the demand. Brussels has begun building the financing scaffolding, with the European Commission and the EIB launching the 10 million euro Sustainable Water Advisory Facility in March 2026, and the EIB planning more than 15 billion euros of water financing over 2025-2027. The private side has the capacity: KKR's co-head of European infrastructure argues that the continent needs to roughly double infrastructure spending toward 700-800 billion dollars a year, while around 435 billion euros of European private-equity dry powder sits idle. The constraint is not money in aggregate. It is the scarcity of bankable, well-structured projects that turn a water-engineered data centre into something a balance sheet can underwrite.
What it means for capital allocators
The Italian answer to AI's water demand is a bounded engineering and capex market inside essential infrastructure, and it is fragmented enough to reward operators ahead of balance-sheet size. The work is specific and repeatable: closed-loop cooling plants, non-potable supply connections, heat-recovery links to district-heating networks, plus the metering and controls that make reuse verifiable to a regulator. Each of these pieces lives in a mid-market niche of engineering firms, utilities and water-services companies that no single champion dominates, which is the configuration in which disciplined buy-and-build and operational improvement create value. The demand anchor is unusually durable, because a data centre is not cheaply relocated once built and its cooling obligations last for the life of the asset. A single Milan cluster of roughly 2 GW implies hundreds of megawatts of cooling and heat-recovery plant to be designed, financed and operated over the next decade. It is a construction and services programme with a water layer still being assembled, and its economics reward those who know how to build it and run it.