Microsoft has prioritized water stewardship since its first datacenter builds in the early 2000s, underpinning its Community-First AI Infrastructure initiative and commitment to become water positive by 2030. Through continuous innovation in cooling technologies, the company improved its water use effectiveness (WUE), measured in liters per kilowatt-hour (L/kWh), by nearly 90% since its first generation of datacenters, with average WUE dropping from 2.3 L/kWh to 0.27 L/kWh in 2025. Microsoft is committed to a 40 percent improvement in datacenter water-use intensity by 2030, and as of 2025, it has reduced water-use intensity by 25 percent. In FY25, Microsoft reached an important milestone toward its 2030 water positive commitment, replenishing more water than it withdrew across its global operations for the year. Early designs prioritized water efficiency through high-efficiency economizing chillers, and by 2008, direct air cooling with evaporative assist became the primary approach, using up to 90% less water than traditional systems by relying on water only when outside temperatures exceed 85°F (29.4°C). Approximately 90% of Microsoft’s 2025 owned fleet operates using highly efficient, low- to zero-water cooling systems.