Assembly hearing urges better data on water use by data centers and other large CII users

Summary

At an informational hearing, California State Assembly members heard agency and expert testimony that existing CII reporting leaves gaps—especially for data centers whose cooling systems are classed as ‘process water’—and called for more granular data, local planning tools and targeted best-management practices rather than one-size-fits-all cuts.

The California State Assembly convened an informational hearing on March 12, 2026, to examine commercial, industrial and institutional (CII) water use, with particular attention to data centers and gaps in current reporting. Chair Pappan opened the session by saying, "We're here today to discuss the future of California's water at a moment when the state is trending toward the possibility of yet another low water year," and asked state agencies and experts to explain what the legislature needs to know to plan.

The hearing brought technical staff from the Department of Water Resources and the State Water Resources Control Board, water-supplier representatives and independent researchers. Ryan Bailey of the Department of Water Resources described the planning framework that governs suppliers—urban water management plans (UWMPs) updated every five years and water-supply assessments (WSAs) required for large projects—and reminded the committee that the statute exempts "process water" (which statute and staff say includes data-center cooling water) from some statewide performance targets. "Data center cooling water is considered process water by statute," Bailey said, noting that WSAs and local planning remain central tools for assessing large developments.

Eric Ekdahl of the…

Assembly hearing urges better data on water use by data centers and other large CII users

Summary

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