The United States Department of the Interior (DOI), Bureau of Reclamation (Reclamation) Lower Colorado Region and the New Mexico Interstate Stream Commission (NMISC) are preparing an environmental impact statement (EIS) for the New Mexico Unit (NM Unit) of the Central Arizona Project (CAP).


The Colorado River Basin Project Act of 1968 and the Arizona Water Settlements Act of 2004, Public Law 108-451 (AWSA) authorized the CAP to deliver Arizona's allocation of Colorado River water to central and southern Arizona. The AWSA also authorizes the Secretary of the Interior (Secretary) to contract with water users in New Mexico for water from the Gila River, its tributaries including the San Francisco River in New Mexico, and underground water sources. The Secretary of the Interior may contract with users in New Mexico for up to an annual average of 14,000 acre-feet of water over any consecutive 10-year period for consumptive use of water from the Gila River in exchange for delivery of CAP water to downstream users in Arizona. This consumptive use is over and above consumptive uses provided by Article IV of the Decree of the Supreme Court of the United States in Arizona v. California, 376 US 340 (1964).

The NM Unit is the proposed infrastructure that would divert Gila River water in New Mexico for this purpose. The AWSA contains specific requirements for the Secretary of the Interior regarding the possible construction, operation, and maintenance of a NM Unit on the Gila River in New Mexico. The AWSA ratified the Consumptive Use and Forbearance Agreement (CUFA), signed by Gila River users downstream in Arizona and New Mexico. The CUFA details the conditions that must be met for New Mexico to be able to divert water from the Gila River and its tributaries, including the San Francisco River in New Mexico, and underground water sources. The act also provides New Mexico up to $128 million in non-reimbursable funding to develop the New Mexico Unit. The NMISC must approve any contract between the Secretary and New Mexico water users, or any expenditure of the non-reimbursable federal funds allocated to the State of New Mexico.

In accordance with the AWSA, the NMISC exercised its opportunity to be a joint lead in the National Environmental Policy Act (NEPA) process. Following that, Reclamation and the NMISC signed a memorandum of understanding. Reclamation and the NMISC are the joint lead agencies for preparing the EIS and are both responsible for decisions relating to its preparation. The federal decisions regarding implementation of the proposed action are the responsibility of the Secretary.

Purpose and Need

The purpose of the proposed action is to develop a NM Unit of the CAP to allow for consumptive use of water from the Gila River, its tributaries or underground water sources in southwestern New Mexico, diverted in accordance with the CUFA and pursuant to the terms of the AWSA.

The needs for the proposed action are to (a) develop water for delivery at the times, locations, and in quantities that will improve agricultural use, and (b) provide capability for future expansion for authorized beneficial purposes.


The NM Unit of the CAP officially approved their proposed action on July 6, 2018. The proposed action is described in a summary engineering report completed on July 6, 2018, which provides a comprehensive project description and updated cost information.