An information resource for the Commonwealth of Kentucky

Water Use & Cooling

How much water do data centers use?

Water use varies enormously by cooling design. Some facilities consume very little; others consume a great deal. The design is a choice, and it can be a condition of approval.

01The concern

The concern

Evaporative cooling can consume large volumes of water, and in a dry summer that competes with households, farms and local utilities. Communities want to know the actual withdrawal and consumption numbers before a project is approved — not after.

02What the data says

What the data says

  • Cooling approach drives water use more than facility size does. Closed-loop liquid cooling recirculates a fixed volume with limited makeup water. Air-cooled and hybrid systems trade water use for higher electricity use. Open evaporative systems use the most water and the least electricity.
  • The industry trade-off is real: reducing water consumption generally increases energy consumption, and vice versa. There is no design that minimizes both at once.
  • High-density AI hardware has pushed new construction toward direct-to-chip and closed-loop liquid cooling for engineering reasons, which tends to reduce evaporative losses relative to older designs.
  • Withdrawal is not the same as consumption. A facility that withdraws water and returns most of it is different from one that evaporates it. Both numbers should be disclosed.

03What responsible development looks like

What responsible development looks like

  • Disclose projected annual water withdrawal and consumption, at peak and average, before approval.
  • Publish the cooling technology selected and the conditions under which it switches modes.
  • Complete a local water and wastewater capacity study with the serving utility.
  • Fund system upgrades where the project drives them rather than drawing down existing headroom.
  • Consider reclaimed, non-potable or process water sources where available.
  • Include drought contingency provisions in the agreement.
  • Report actual usage annually to the local utility and the public.

04Kentucky context

Kentucky context

Kentucky is comparatively water-rich, with the Ohio, Mississippi, Cumberland, Tennessee and Kentucky river systems and substantial reservoir capacity. That is an advantage, but it does not make local capacity automatic.

Local capacity is what governs. A rural water district's treatment and distribution capacity, not statewide rainfall, determines whether a specific site can be served.

Withdrawal permitting in Kentucky is handled through the Division of Water; wastewater discharge is permitted under KPDES. Those permit records are public.

05Sources

Sources

  • Water withdrawal and KPDES permit records

    Source: Kentucky Division of Water

  • Data center water and energy research

    Source: Lawrence Berkeley National Laboratory

  • Local capacity studies

    Source: Local water districts and municipal utilities

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