California Won’t Cap AI Data Centers’ Water Use — Only Make Them Disclose It

The story California has been telling about itself this year is one of a state finally putting limits on the machines eating its power and water. The version that reached the governor is quieter and more revealing: it does not cap what a data center may draw. It asks the operator to say what it draws, and to pay for the pipes that carry it. The crackdown, stripped of the headline, has become a fight over disclosure — and over who foots the bill for the infrastructure a hyperscale campus demands.

That gap between the framing and the text is the whole story. Regulating a resource means setting a ceiling. What survived the legislative session sets a form to fill out. The distinction matters because it marks where the industry drew its line and held it: transparency, grudgingly; hard limits, not at all.

The measures with real teeth are the ones that did not make it. A push to shield ordinary ratepayers from the cost of grid upgrades that data centers trigger was held over. An effort to force operators to disclose their electricity use was routed into the Senate’s suspense file, where bills go to die quietly. What emerged intact was a directive for the California Public Utilities Commission to study data center energy costs by 2027 — a study of a problem regulators already have the authority to investigate. An attorney for The Utility Reform Network called it toothless, and it is hard to read it any other way.

The opposition was not subtle. The Silicon Valley Leadership Group and the Data Center Coalition worked the building, and the governor himself signaled reluctance to impose requirements before he understood the full impact on businesses and the consumers of their technology. That is the posture of a state negotiating with an industry it wants to keep, not one drawing a hard line around it.

What is left on the desk is water, and it is worth reading closely for what it does not do. Assembly Bill 2469 sets no cap on consumption and mandates no closed-loop cooling — the technology that would actually shrink a campus’s thirst. It requires a would-be developer to file a water-supply and water-use assessment, to weigh closed-loop cooling without adopting it, and, from 2028, to write a scarcity plan describing how the site cuts back across the drought stages the U.S. Drought Monitor tracks. Its sharpest provision is not environmental at all. It makes the developer bear the full cost of any new conveyance, treatment or storage the project needs, blocks construction over critically overdrafted groundwater basins, and lets a city refuse a permit if the analysis falls short. The bite is the money and the local veto, not the water.

A companion, Assembly Bill 2619, would make operators report their actual water use under penalty of perjury when they license or renew — it cleared the Senate by a wide margin. Around them sits a larger docket that shows what a real regime would look like: a dedicated tariff for the biggest campuses that forces them to pre-fund clean power, monthly efficiency reporting to the Energy Commission, an end to the environmental-review exemptions that let these projects skip scrutiny. Those are the frameworks. The water bills are the compromise.

And the compromise is not safe. Governor Newsom vetoed a nearly identical water-disclosure bill last October, and the same author has sent him the same idea again, telling reporters the opportunity for leadership has only been amplified. He has until the end of September to decide whether reading a company’s water bill is a burden California can ask an industry to bear.

Here is the tell. If he signs, the fight over AI’s footprint in California moves from whether operators must open their books to how much of the tab they carry — a narrower, more winnable war for the companies. If he vetoes a second time, the state will have told every hyperscaler shopping for a site that its appetite for accountability is smaller than their appetite for water, and priced accordingly.

Tags: california, Gavin Newsom, AI data centers, data center regulations, data center water use