CyrusOne Chandler (Phoenix Campus) data center, Chandler, Arizona

CyrusOne runs a data center campus along South Ellis Street in Chandler, Maricopa County, Arizona: eight buildings the company puts at 2 million square feet of technical space and 169 megawatts of power. None of the eight buildings uses water to cool; the campus draws about 180,000 gallons a year only for humidification, which CyrusOne calls the first net positive water data center in its portfolio.

Arizona's data centers together were expected to use about 905 million gallons of water in 2025, roughly what 10,000 Phoenix-area homes use in a year and less than a tenth of one percent of the state's water. Chandler has limited a data center to 115 gallons a day per 1,000 square feet since 2015, with anything more brought in from outside the city supply.

The city also wrote zoning rules for data centers before most American cities had considered them: an ordinance adopted in 2022 and in effect since January 5, 2023, confining the use to certain zoning and requiring resident notification, a baseline sound study and limits on testing backup generators.

"Unlike energy, using water to cool a data center is a choice, not a requirement," said Alex Setmajer of Equinix. CyrusOne says its newest data centers, built from 2024 onward, use zero-water cooling company-wide.