The water question: cooling data centres without draining the community

On the driest inhabited continent, any large new water user invites scrutiny — and data centres can use water to keep cool. But water use varies enormously with design and location. With the right choices, it can be modest, transparent and uncontroversial.

After energy, water is the resource most often raised about data centres, and for good reason: in a dry country, communities are right to ask whether a new facility will compete with households, farms or the environment for a scarce resource. The honest answer is that it depends almost entirely on how the facility is cooled and where it is built — both of which are choices, not fixed facts.

Why water comes up

Many cooling systems use evaporation to shed heat, and evaporative cooling consumes water. At scale, that can be significant, which is why “how much water?” is a fair and increasingly common question. The concern sharpens in water-stressed regions, where any large new draw on potable supply is hard to justify.

It’s a design and siting choice

Cooling sits on a spectrum. Evaporative systems use more water but less energy; closed-loop and air-cooled systems use little or no water but can use more energy, especially in hot climates. There is a genuine water-versus-energy trade-off to manage. Crucially, water source matters as much as volume: using recycled, non-potable or rainwater for cooling is very different from drawing on drinking-water supplies. And siting matters most of all — water-intensive cooling belongs where water is genuinely abundant, not in catchments already under stress.

What good looks like

A few principles keep water use defensible. Be transparent: disclose expected water use and its source, so communities and regulators can judge it. Avoid potable water for cooling wherever possible, favouring recycled or non-potable sources. Match cooling to climate: choose designs suited to local conditions rather than a one-size template. And account for water in approvals, alongside energy, rather than treating it as an afterthought. None of this is exotic; it is simply planning the resource in from the start.

Tasmania as a worked example

Tasmania’s position is favourable here. A cooler, wetter climate reduces cooling demand in the first place and eases the water-stress concerns that dominate on the mainland — and cooler ambient temperatures make low-water cooling designs more practical. That does not remove the need for care: transparency about water use and source still matters, and local catchment conditions still deserve attention. But it does mean Tasmania can pursue digital infrastructure without the acute water trade-offs facing hotter, drier jurisdictions — provided the choices are made deliberately.

A manageable concern

Water is a legitimate question, but it is a manageable one. The volume a data centre uses is not destiny; it is the product of decisions about cooling technology, water source and location. Made openly, and made with the local context in mind, those decisions turn water from a flashpoint into a non-issue — and protect the community trust that every project ultimately depends on.

Part of the Digital Infrastructure Institute’s series on planning Australia’s digital infrastructure.