Domestic (United States)

1) Cooling & water use: what’s actually “regulated” in the U.S.

In the U.S., there is no single federal “data center water law.” Instead, water/cooling is governed through environmental permits, water rights/withdrawal rules, and local utility approvals.

Main regulatory hooks:

Water withdrawals / water rights (state water law + river basin rules): whether you can take water from a source (surface/groundwater), how much, and when.

Discharge / thermal impacts (federal Clean Water Act via state agencies):

If you discharge wastewater (including cooling water blowdown) to surface waters, you may need NPDES permitting and must meet limits (often including temperature/thermal criteria depending on receiving waters).

Stormwater & construction (CWA construction general permits) for large site builds.

Local water/sewer utility rules (capacity, industrial discharge limits, cooling tower blowdown quality, connection approvals).

Land use/zoning & environmental review (county/city planning; in some states an environmental review statute).

Chemical handling (cooling water treatment): depending on volumes/chemicals, may trigger state/federal storage/reporting requirements.

Who governs/enforces

State environmental agencies (often delegated EPA authority) for NPDES and water quality.

State water resources departments / boards for withdrawals and water rights.

Municipal water/sewer utilities for supply contracts and discharge acceptance.

Local planning/zoning boards for siting constraints (sometimes the biggest practical limiter).

The U.S. policy spotlight on data center water intensity has accelerated (especially around drought- or basin-stress concerns), but it still typically translates into local/state permitting decisions, not a single federal data-center standard.
Congress.gov

2) Power consumption / energy efficiency: federal vs. state reality

Federal (directly applicable mostly to federal agencies’ own data centers)

Federal agencies are directed to evaluate data centers periodically for efficiency (statutory language focuses on federal operations).
U.S. Code

DOE’s FEMP publishes operational guidance for reducing cooling-water use in federal data centers (guidance, not a general private-sector mandate).
The Department of Energy's Energy.gov

Private sector (most requirements come from states/utilities + building codes)

Building energy codes (state adoption of IECC/ASHRAE-based codes; California Title 24 is a major example) affect electrical/mechanical design, economizers, heat rejection choices, and sometimes monitoring.

Utility interconnection and service agreements can impose:

load study requirements,

substation build-outs,

demand response / curtailment participation,

and sometimes energy efficiency or emissions-related conditions as part of approval processes.

Air permits if you run large generator fleets (diesel/natural gas). This affects runtime limits, testing schedules, and emissions controls (big factor for resiliency design).

Who governs/enforces

State Public Utility Commissions (PUCs) (retail electric regulation) + the utilities themselves.

Local building departments (mechanical/electrical code enforcement).

State environmental agencies / air districts for generator air permits.

3) U.S. “reporting” pressure (not always “regulation,” but effectively mandatory)

Even where not required by law, customers, investors, and public entities increasingly demand standardized metrics like:

PUE (Power Usage Effectiveness)

WUE (Water Usage Effectiveness)

site energy mix / renewable matching

The U.S. Congressional Research Service notes the growing policy focus on data center energy and water consumption, including water used for cooling and for electricity generation.
Congress.gov

Foreign (EU focus, then “other”)
European Union
A) Energy Efficiency Directive (EED, revised 2023): mandatory data center reporting

This is the biggest “hard” EU rule aimed directly at data centers right now.

What it does:

Introduces an obligation for monitoring and reporting of data center energy performance.

Creates a European database that collects and publishes information relevant to energy performance and water footprint for data centers with significant energy consumption.
Energy

Who must report (threshold)

Reporting applies to EU data centers meeting a threshold (commonly described as installed IT power demand ≥ 500 kW).
White & Case

How the “what to report” gets specified

The EED reporting obligation is implemented through detailed rules, including Commission Delegated Regulation (EU) 2024/1364, which sets the reporting content/format and KPI expectations.
EUR-Lex

Governing bodies:

European Commission (database + delegated rules)

Member State authorities (transposition/enforcement and ensuring operators submit data)
Energy

B) CNDCP / “Climate Neutral Data Centre Pact” (voluntary, but influential)

This is not a law, but in practice it can function like one because customers, cities, and investors treat it as a baseline.

Key commitments include targets around:

PUE targets for new sites (differentiated by climate region),

renewable/clean energy matching milestones,

broader sustainability actions.
Climate Neutral Data Centre

European Parliament

Why it matters operationally

It pushes design toward lower PUE, better heat reuse, and more transparent sustainability metrics—often aligning with what EED reporting will expose publicly anyway.
Climate Neutral Data Centre

C) CSRD (Corporate Sustainability Reporting Directive): mandatory sustainability disclosure

CSRD is company-level reporting (not “data center-specific”), but it becomes effectively mandatory for many operators/owners/large tenants in the EU value chain, and it drives formal disclosure of:

energy, emissions, climate risk,

and often water impacts where material.

Primary legal source

Directive (EU) 2022/2464 (CSRD).
EUR-Lex

Water reporting hook

CSRD disclosures are made using ESRS standards, including ESRS E3 (Water and Marine Resources), which requires disclosures related to water consumption and impacts when material.
EFRAG

Governing bodies:

EU lawmakers (directive), national competent authorities for enforcement, assurance/audit ecosystem; ESRS are maintained/published through the EU process (with EFRAG’s role in standards development).