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.
La Palma
There is an extensive network of irrigation canals in the valley of "Los Llanos de Aridane". These canals carry water from the mountains throughout the valley and allow for the cultivation of bananas, avocados, flowers, and other plants. Each farmer gets a scheduled "turn" to fill an irrigation tank with water 24 hours of the day. If a farmer's turn is at 2 AM he will wake up and make sure to fill his tank when possible so as to have sufficient water for his farm.