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 Conservancy District
The Pueblo people of the Rio Grande valley had developed primitive irrigation systems in the Rio Grande valley by the 10th century AD.
These systems used a main "acequia" (shared irrigation ditch) into which water was diverted from the river, with secondary ditches leading off the main channel named for specific families. Maintenance of the main "acequia" would be a community responsibility.
The Spanish arrived in New Mexico in 1598, and used Indian labor to extend the system of irrigation ditches.
In 1848 Mexico ceded the territory to the United States. Railways arrived in 1880, bringing new settlers.
The Federal government encouraged irrigation, which probably peaked in the early 1890s.