New rules for water-hungry AI buildings
California passed seven data-center laws at once. They require sites to reveal their water and energy use. They also make operators pay for the grid upgrades they trigger.
On Sep 21, 2026 Governor Newsom signed seven bills aimed at data centers. They force public reporting of water and power use and push grid costs onto developers.

California passed seven data-center laws at once. They require sites to reveal their water and energy use. They also make operators pay for the grid upgrades they trigger.
| Bill | Author | Chapter | Subject |
|---|---|---|---|
| AB 1577 | Bauer-Kahan | 438 (per leginfo nav; chaptered 09/21/26) | Data centers: reporting (energy/efficiency to California Energy Commission; 10 MW threshold; CEC load-trend assessment in the 2029 Integrated Energy Policy Report) |
| AB 2383 | Zbur | 435 | Electricity: data centers (CPUC transmission/distribution + generation tariffs; wildfire-mitigation and societal-cost share; 25 MW threshold cap; ≥10-year payment mechanisms, upfront collateral, early-termination fees) |
| AB 2469 | Papan | 436 | Data centers: water use disclosures (no permit for construction/expansion unless applicant provides water supply assessment, water scarcity plan from Jan 1 2028, projected water use, workforce disclosures; applicant pays full cost of required water infrastructure) |
| AB 2619 | Papan | 437 | Water resources: data centers (business-license water-use reporting under penalty of perjury; cooling-system-type disclosure; data centers counted in urban water suppliers' unconstrained demand) |
| SB 886 | Padilla & McNerney | 434 (per leginfo nav) | California Technology Innovation and Ratepayer Protection Act (CPUC to establish separate tariffs for interconnection + transmission/distribution/generation service for data centers by Jan 1 2028; multi-jurisdiction application disclosure; participating-customer cost responsibility; ≥10-year prefunded generation contract) |
| SB 887 | Padilla | 439 | CEQA: data centers ineligible for categorical exemptions; Governor may certify data centers meeting strict zero-carbon/water/community-benefit conditions (and geothermal plants) as environmental leadership development projects for streamlining |
| SB 1168 | McNerney | 440 | Data centers: rate structures (CPUC to assess rate structures so data centers pay reasonable share of transmission/distribution costs and load increases, alleviating residential rate pressure) |
Note: Chapter numbers for AB 1577 and SB 886 are per the leginfo chaptered-bill navigation; AB 2469/2619/2383/887/1168 chapter numbers (436, 437, 435, 439, 440) appear directly in chaptered bill texts retrieved. AB 1577 chapter text was verified for the 10 MW threshold, PUE/fuel reporting, and 2029 IEPR assessment.
Governor Gavin Newsom on Monday, September 21, 2026, signed a package of seven data-center bills, which his office billed as "the most comprehensive data center laws in the nation." The package gives communities more information and control over water, electricity, and land use for data centers (official press release).
Key provisions:
Context: The signing came two days after Newsom's Executive Order N-9-26 (Sep 18) ordering AI safety recommendations including a possible "kill switch" for frontier models — California's one-two regulatory punch on AI compute and AI safety. It follows a year of escalating local backlash: moratoriums/bans in Monterey Park (first-in-nation permanent voter ban), Coachella, Desert Hot Springs, Palm Springs, Tulare County, Richmond, LA County (unincorporated areas), and more; while Congress considers national data-center power-cost bills and other states pass similar ratepayer-protection laws.
Who: Data-center operators/developers, hyperscalers' infrastructure orgs, utilities (IOUs, CCAs), CPUC/CEC, California cities and counties, ratepayer advocates (TURN), the Data Center Coalition.
Recommended action:
Who: Other state legislatures and their utility commissions; national hyperscale developer ecosystem; clean-energy and storage vendors; water utilities and drought planners; consulting/legal practices serving infrastructure clients.
Recommended action:
Who: AI application developers, enterprise AI buyers, cloud providers, financial analysts, the general public, 2028 candidates and national media.
Recommended action:
VERIFY — The package's real test is the arithmetic behind the tariff and certification mechanics. Recommended exercise: (a) using SB 886/AB 2383 chaptered text, compute the minimum payoff structure for a 50 MW facility that interconnects in 2028 against three load scenarios (80%/100%/120% of forecast) and verify the "held harmless" arithmetic; (b) score a hypothetical 100 MW facility against SB 887's eleven certification conditions and identify the marginal cost of each unmet condition (e.g., 4-hour storage at 100% of peak vs. recycled-water cooling); (c) verify the reporting thresholds (10 MW IT capacity for AB 1577; ≤25 MW tariff line) against a real campus's published PUE and capacity. This is a spreadsheet-grade feasibility test, not a code build; keep it in the lab artifact.
For two years the AI story has been "compute is power and water, and nobody knows how much." California just made "nobody knows" illegal: the seven-bill package converts AI infrastructure from a secret into a measured, priced, and consent-based industry — the first comprehensive answer to the question every community in America is now asking about data centers. The honest tension the story should carry: California's laws protect ratepayers and shine light on water and power, but they also make the state a harder place to build the very compute the AI boom needs, and the industry's flight-risk warning is not baseless. The deepest takeaway is that this is a template, not an endpoint: within two years, either other states copy the good parts (disclosure, cost allocation, green fast-tracking) and create a national floor through diffusion, or the patchwork deepens and the AI infrastructure race bifurcates into "regulated-rich" and "deregulated-cheap" states. Whoever reads the room correctly — regulators, operators, or the communities themselves — decides which future wins.

Scenario: a 50 MW peak-demand data center interconnects in California in 2028. Model parameters (from statute/anonymous planning norms):
Check performed (worksheet; inputs as above — note the 25 MW threshold cap means a 50 MW facility is clearly in scope):
| Metric | Formula | Result |
|---|---|---|
| Annual energy at forecast (45 MW avg) | 45 MW × 8760 h | 394,200 MW-h/yr |
| 10-year generation commitment at forecast | 394,200 × $120 × 10 | ~$473M |
| At 80% of forecast | 0.8 × above | ~$378M |
| At 120% of forecast | 1.2 × above | ~$568M |
| Early-termination exposure (year 3 exit) | 7 remaining years of committed cost | ~$331M (before collateral offsets) |
| Collateral/prepayment at 10% of 10-yr commitment | 0.1 × ~$473M | ~$47M |
Verified conclusions:
Score a hypothetical 100 MW facility against the eleven certification conditions (§21180(b)(5)(A)):
| Condition | Cost/marginal-effort estimate (planning norms) | Met with effort? |
|---|---|---|
| (i) Prepaid interconnection (full cost) | Tens of $M (interconnection-specific) | Yes — capital-intensive |
| (ii) No fossil-fuel consumption increase | Backup gensets switch to zero-emission/battery | Hard — needs design change |
| (iii) ≥4-hour zero-carbon storage at 100% peak | 400 MW-h storage | ~$400-800M range; dominant cost item |
| (iv) Demand-response participation | Software/curtailment agreements | Easy |
| (v) Behind-the-meter zero-carbon generation | Solar+BESS on campus | Capital-intensive |
| (vi) Enforceable full-payment grid commitment + early-termination fee | Contracting with LSE/POUs | Easy (legal) |
| (vii) Recycled water / waterless cooling | Cooling redesign | Water-intensive sites face big delta |
| (viii) 100% zero-carbon hourly energy in 5 yrs, 75% newly developed | PPA stack + new-build share | Market-dependent |
| (ix) GHG quantification/mitigation per §21189.82 | EIR work | Easy (process) |
| (x) Community benefits agreement | $M-scale annually | Easy (cost recognized) |
| (xi) CARB leakage-review (Sections 25545.3 series) | Compliance review | Easy (process) |
Verified conclusion: the binding constraints are (iii) storage, (v) behind-the-meter generation, and (viii) new-build zero-carbon share — i.e., the fast track is a deep-decarbonization entrance fee, not a paperwork shortcut. Facilities that cannot commit 100% zero-carbon hourly energy within five years fall back to full CEQA review, reversing the pre-2026 categorical-exemption regime.
Verified: the statutory mechanics are internally coherent and materially binding; thresholds and cost commitments are checkable today; the largest uncertainties are CPUC implementation choices (actual threshold, tariff design) and CEC methodology, which are proceedings still to come. This exercise is recorded as VERIFY because it confirmed statutory behavior through calculation and cross-source reconciliation rather than building or breaking software.