In August 2024, Microsoft formally committed that all new data center designs would adopt chip-level, closed-loop liquid cooling technology that eliminates evaporative water consumption entirely. This represents the most significant water engineering commitment made by any hyperscale operator to date. Pilot facilities are operational in Phoenix, Arizona and Mt. Pleasant, Wisconsin. The Mt. Pleasant facility — located on 1,575 acres in rural Wisconsin — documents water savings exceeding 33 million gallons annually versus the legacy design it replaces. This white paper documents the engineering architecture, the measurable efficiency trajectory, and the policy implications for data center development advocacy.