Overview
Cooling Design Sets a Data Center's Water Footprint
Evaporative cooling towers reject heat by evaporating water, and most of the water drawn never returns to the local supply. Closed-loop systems circulate the same coolant and need only an initial fill and makeup water. Air-cooled systems use almost no water on site but draw more electricity, which moves water use upstream to thermal power plants unless the campus generates its own power. The industry measure is water usage effectiveness (WUE): liters of water per kilowatt-hour of IT load.
Microsoft's next-generation data center design, announced in December 2024, uses closed-loop, chip-level liquid cooling that does not evaporate water for cooling; Microsoft says it saves more than 125 million liters a year per data center. Google says its Meitner Energy Center in Gray County will use air cooling and limit water to domestic use such as restrooms.
| Data center water use | Mostly heat rejection |
|---|---|
| Fab water use | Mostly ultrapure wafer rinse |
| Efficiency measure | WUE, liters per kWh |
| Lowest-water cooling | Air-cooled, closed-loop liquid |
| Highest-water cooling | Evaporative towers |
| State review | PUCT and ERCOT audit, Aug 3, 2026 |
| Permit status | TCEQ data center permits paused Sept 21, 2026 |
Fabs
Fabs Need Ultrapure Water and Can Only Recycle It
Chipmaking rinses wafers in ultrapure water (UPW) purified to about 18 megohm-centimeters resistivity, far cleaner than drinking water. Industry estimates put the intake at roughly 1,400 to 1,600 gallons of city water for every 1,000 gallons of UPW, because reverse osmosis and ion exchange send part of the feed to reject streams. A large fab draws millions of gallons a day.
Fabs cut outside demand by reclaiming rinse water and reusing reject streams for cooling towers and scrubbers. In Texas, Samsung's Taylor fab sits on the Brazos River Authority's Lake Granger system, and the Terafab site in Grimes County comes with the former Texas Municipal Power Agency river intake at Gibbons Creek Reservoir.
Sourcing
Non-Potable Sources Avoid Competing With Towns
Drawing potable city water draws the opposition; drawing water nobody else can use does not. Microsoft says its Pecos campus in Reeves County will run closed-loop cooling on non-potable water where possible, and Chevron says the gas plant serving it will use brackish groundwater. Google has paired Meitner with a $10M Texas Water Impact Fund for community water systems. Other campuses use treated municipal wastewater and pay for the treatment upgrades.
State Review
The Texas Audit Asks for Water Use, Source and Cooling Type
Governor Greg Abbott's August 3, 2026 order directs the Public Utility Commission of Texas (PUCT) and the Electric Reliability Council of Texas (ERCOT) to audit every data center in the large-load interconnection queue. Alongside on-site power, each project must report how far it brings and reuses its own water, projected annual and peak water consumption, supply sources, and cooling technology, including air-cooled or closed-loop systems. Projects that fail the audit can be denied grid connection.
On September 14 Abbott added the Texas Water Development Board (TWDB), ordering penalties for data centers that skip its water use survey. On September 21 he ordered the Texas Commission on Environmental Quality (TCEQ) to pause data center air and water permits, including permits for on-site power, until the ERCOT review ends, expected mid-December 2026. See Texas Water Supply and Stress and Behind-the-Meter Power.
Record
Dataset Record
- Sources
- Office of the Governor of Texas, Texas Tribune, Microsoft, Google, POWER Magazine, The Register, Brazos River Authority, KWTX, Sensorex, ITPro
- Last verified
- October 2026