Instream Flows in New Mexico

Santa Fe River from Frenchy's FieldIn New Mexico, an arid state where competition for water is one of its defining characteristics, scant attention has been paid to the health and sustainability of its more than 1,000 miles of creeks, streams and rivers. But that is changing. The water in rivers that is dedicated to the function of rivers, such as providing habitat for species, water for recreation or water for maintaining the sediment flows of a river, known as instream flows, is now viewed as part of a larger picture, in which the restoration or protection of ecosystem functioning is a goal that is supported by appropriate flows of water. These flows may be defined by timing, water quality and temperature, as well as other relevant qualities. Meanwhile, other western states have moved forward with programs for protection of instream flows.

Jesse A. Boyd ('03), Hip Deep: A Survey of State Instream Flow Law from the Rocky Mountains to the Pacific Ocean, 43 Nat. Res. J. 1151 (2003).

Interpreting the Law

The legal system that creates rights to water in New Mexico has been part of the impediment to protecting instream flows. The prior appropriation doctrine governs water in most of the western U.S.; it provided a means of establishing rights in water in the earliest years of the state. Under this doctrine, water had to be removed from a stream and put to a “beneficial use” before a water user would have an exclusive right to the water. The requirement that water be diverted from the stream gave no protection to flows within rivers and the aridity of the state led to full appropriation of the state’s waters. Throughout the years, however, the interpretation of the law has changed with changing social values. Indeed, in 1988, a UNM School of Law class successfully procured from New Mexico Attorney General Tom Udall an opinion, which established that New Mexico law permits instream flows to be a “beneficial use” under specified conditions.

The Opinion of Attorney Tom Udall, Opinion No. 98-01 (Mar. 27, 1998)
Denise D. Fort, Instream Flows in New Mexico, 7 Rivers 155 (2000).

Recognizing Water Rights

New Mexico state officials have recognized that the federal government can hold water rights for environmental purposes, such as for maintaining fish on the Red River.

The state has a law that authorizes the purchase of water for instream flows for compliance with the Endangered Species Act and water delivery requirements under the various compacts that apportion the water in the state's waterways. Additionally, the New Mexico Environment Department administers the River Ecosystem Restoration Initiative, under which funds can be given for water leases or purchases.

States Law: NMSA § 72-14-3.3. Interstate Stream Commission; Additional Powers; Strategic Water Reserve.
New Mexico Office of the State Engineer: Interstate Stream Commission
Ecological Flows in New Mexico — It Has Been Done, Adrian Oglesby (Powerpoint Presentation)

Supporting Instream Flows

The federal Endangered Species Act has provided the greatest support for instream flows in the West, although the act is invoked only after a species is in danger of extinction. In New Mexico there are endangered species recovery programs on the Rio Grande, Pecos, San Juan and Gila rivers. The programs provide funding for activities such as construction of refugium, scientific studies, water leases, etc. The Middle Rio Grande Endangered Species Collaborative Program was started in response to litigation over the Rio Grande Silvery Minnow and now involves a host of collaborating water agencies.


There is much to be done before New Mexico’s rivers and streams are restored to healthy conditions. While biologists, engineers, ecologists and graduates of other disciplines have key roles, lawyers are an integral part of the solution. Graduates of the UNM School of Law are found throughout the water law world, in private practice, working for environmental NGOs, for tribal governments and for the state and federal government.


The UNM School of Law extends its appreciation to the Kenney Foundation for the support of Professor Denise Fort's research in this area.

Professor Denise Fort

Professor Denise Fort

Professor Denise Fort has an extensive background in environmental and natural resources law - about 25 years of practice, politics, reflecting and writing about policies, all animated by a belief that society must turn toward a more sustainable relationship with its environment. She believes that law plays a critical role in establishing the institutions that govern those relationships.