News

New water regime in Mexico: Enactment of the General Water Law and substantial amendments to the National Water Law

11 December 2025

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Key takeaways

The Federal Executive has published in the Federal Official Gazette the Decree enacting the General Water Law (“LGA”) and simultaneously reforming and repealing various provisions of the National Water Law (“LAN”).

The new Law fundamentally reshapes Mexico’s water governance model: it creates the National Water Public Registry (“REPNA”) to replace the Public Water Rights Registry; redefines the rules applicable to water concessions, extensions, transfers, and reallocations; and establishes a National Water Reserve Fund to redirect volumes to priority uses.

The Decree introduces specific regulation for rainwater harvesting, strengthens the regulatory framework for wastewater reuse, and creates a significantly more robust administrative and criminal sanctioning regime, including new categories of water-related offenses.

At its core, the General Water Law is built around the human right to water and sanitation, the State’s authority over water management, and basin-based planning, representing a structural shift for all productive sectors in Mexico.

On December 11, 2025, the Federal Official Gazette published the “Decree enacting the General Water Law and reforming, repealing, and amending various provisions of the National Water Law” (“Decree”).

The Decree responds to Mexico's long-standing water crisis, characterized by aquifer over-exploitation, increasing pollution, unequal access, insufficient wastewater treatment, and an outdated regulatory framework that no longer fulfills the constitutional mandate to guarantee the human right to water.

The reform emphasizes that the LAN was built on a patrimonial and market-driven model centered on concessions and transfers of “rights,” whereas the new LGA seeks to reorient the entire system around State stewardship, equity, sustainability, and water justice, establishing the foundation for a new governance model based on basin management.

Amendments to the National Water Law

National Water Registry (“REPNA”)

The Decree eliminates the Public Water Rights Registry and replaces it with the National Water Registry, a centralized system for all concessions, assignments, discharge permits, modifications, and compliance information.

Concessions regime

Assignments: The Decree restricts the transfer of concessions, eliminating the previous market-based model.
Reallocations: The Decree introduces the figure of reallocation, through which the authority may redistribute water volumes when they are unused, used contrary to the terms of the title, concentrated in a way that limits availability, or when needed to support priority uses. This tool is designed to promote equitable and sustainable water distribution.

Reallocation may also be used when: (i) title-related land ownership is transferred; (ii) corporate mergers or demergers occur; or (iii) succession rights are proven.
Extensions (Prórrogas): To obtain an extension, the authority will evaluate: (i) compliance with title conditions; (ii) current water availability; and (iii) compliance with fiscal obligations.

In addition, extension requests must be submitted within the last three years of the title’s validity and at least six months prior to expiration.

Rainwater harvesting regulation

The Decree introduces specific regulation for rainwater harvesting, promoting urban, industrial, and domestic systems as mechanisms to relieve pressure on basins and aquifers. Industrial or commercial rainwater capture now requires prior authorization.

Wastewater reuse

The Decree promotes a model in which treated wastewater reuse becomes mandatory in certain sectors and is encouraged through efficiency-based criteria.

Sanctioning regime

The new framework significantly strengthens enforcement powers:

Administrative sanctions: fines, revocation of concessions, shutdowns, remediation orders, and suspension of activities.
Water-related criminal offenses: illegal extraction, manipulation of hydraulic infrastructure, intentional contamination, and illicit trade or commercialization of water volumes.

General Water Law (LGA)

The LGA aims to:

Guarantee the human right to water and sanitation, under standards of sufficiency, safety, acceptability, accessibility, and affordability;
Clearly define the distribution of powers among the Federation, states, municipalities, and communities; and
Strengthen public participation, basin-based planning, and ecosystem protection.

The LGA stands as the central instrument guiding Mexico’s transition toward a more equitable and sustainability-driven water management model.

Transitory provisions

The Decree provides that within 180 calendar days from its effective date, the corresponding regulatory provisions must be issued or amended. Until then, existing regulations remain applicable, provided they do not contradict the new Law’s principles and directives.
Concession, assignment, and discharge permit procedures already underway before the National Water Commission (CONAGUA) at the time of publication must be resolved under pre-existing regulations, so long as these do not conflict with the new Decree.

Authored by Mauricio Llamas, Mauricio Villegas, Sofia de Llano, and José Pablo Navarro.

Next steps

Following the publication of the General Water Law, concession holders should promptly review the status of their existing titles and permits particularly those approaching expiration, and prepare extension requests in advance (within the last year of validity and at least six months before termination). It is also advisable to assess potential caducity risks related to unused volumes and maintain documentation supporting any periods of inactivity.

Given the strengthened oversight framework, companies should reinforce measurement systems, reporting practices, and fiscal compliance, while anticipating the impact of the prohibition on transfers and the possible use of reallocations. Industrial users should evaluate whether upgrades to treatment and reuse infrastructure are required under the new obligations. Finally, monitoring the regulations to be issued over the next 180 days will be essential, as these rules will define the operational procedures under the new water regime.