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.
Albuquerque Basin
The Pueblo people of the Rio Grande valley had developed primitive irrigation systems by the 10th century AD, and by the 13th century most of the major pueblos had been established. The Pueblo system of irrigation ditches is one of the oldest of the irrigation systems in North America. 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 steadily expanded their presence, founding Albuquerque in 1706. The Spanish used Indian labor to extend the system of irrigation ditches. Again, once a community grew large enough they would form a community association to look after maintenance. The Spanish were familiar with Moorish irrigation techniques, and may have adapted them to the canals that had been built by the Pueblos.