The ecological impact on the river and the riparian zone was the subject of extended litigation after a group of environmentalists filed Rio Grande Silvery Minnow v. Bureau of Reclamation in 1999.

The Rio Grande valley from Taos Pueblo downstream to Socorro has been continuously settled for longer than any other part of the United States.

The Bureau of Reclamation was responsible for rehabilitating the El Vado dam, the irrigation and drainage works and the river channel.

The Bureau of Reclamation operates and maintains El Vado Dam and the river from Velarde to the Narrows of Elephant Butte Reservoir.

[1] In 1934-1935 the conservancy district built the El Vado Dam on the Rio Chama about 160 miles (260 km) north of Albuquerque to store irrigation water for use in dry periods.

In 1951 the Bureau of Reclamation began construction of the low-flow conveyance channel between San Acacia Diversion Dam and the Narrows of Elephant Butte, completing the job in 1959.

In 1961 the Bureau of Reclamation completed modification of the headworks for the Socorro Main Canal north at San Acacia Diversion Dam.

Maintenance along a 149-mile (240 km) stretch of the river to control floods and reduce non-beneficial use of water through evapotranspiration is an ongoing requirement.

The Bureau of Reclamation has been using alternative methods of channel maintenance since the late 1980s in an effort to improve the quality of the riverine and riparian habitats.

[1] Rehabilitation of the irrigation system throughout the project has resulted in a more stable water supply to about 90,000 acres (36,000 ha) of irrigated land, including water for the six southern Indian pueblos of Cochiti, Santo Domingo, San Felipe, Santa Ana, Sandia, and Isleta, all of which are served by the Middle Rio Grande Conservancy District.

The areas between the cleared floodway and the riverside levees are now filled with a permanent stand of large trees and other dense growths of vegetation.

[1] Citations Sources This article incorporates public domain material from websites or documents of the United States Bureau of Reclamation.