Agriculture in the prehistoric Southwest
After the Hohokam disappeared, Spanish explorers of the 16th century noted the use of canal irrigation in only two areas of the Southwest: eastern Sonora, primarily practiced by the Opata and Lower Pima, and among the Pueblos of northern New Mexico. Irrigation by the Opata and Pueblos had different objectives. In Sonora, with a long growing season, two crops of maize a year were grown in river valleys. The spring crop during the dry season was dependent upon irrigation; the summer and fall crop during the rainy season utilized irrigation to supplement rainfall. The necessity of irrigation probably required a high level of social organization. In New Mexico, with only one crop of maize per year possible, irrigation was supplemental and the lesser dependence on irrigation implies less social organization than in Sonora.
Middle Rio Grande Project
Rehabilitation of the irrigation system throughout the project has resulted in a more stable water supply to about 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.
This supports cultivation of alfalfa, barley, wheat, oats, corn, fruits and vegetables. The river maintenance program, coupled with the Corps of Engineers' flood control dams and system of levees, has greatly reduced the threat of uncontrolled flooding in the Middle Rio Grande Valley.