History
Water shapes history. Human settlement of the Southwest is the story of finding and using water. Before the arrival of Europeans, various tribal people occupied what is now Arizona. The Hohokam settled in the fertile Salt River valley about 250 B.C. and built canals to carry Salt River water for farming. The Hopis grew corn, squash and beans in flood plains and spring- fed terraced gardens.
Beginning in the sixteenth century the Spanish settled and farmed in southern Arizona. By 1888 U.S. homesteaders were farming more than 100,000 acres in the Phoenix area. The Salt River proved a fickle water source, sometimes dry, then flooding. To control the Salt River, Roosevelt Dam was completed in 1911 by the newly created Reclamation Service (later the Bureau of Reclamation) as part of a program of water development projects to settle the West. The dam also marks the beginnings of the Salt River Project, the first multi-purpose reclamation project in the U.S. Now consisting of eight dams and a 1,300-mile water delivery system, SRP also provides electricity, flood protection and recreation. Several major dams were erected on the Colorado River to store its waters (see Colorado River).
The introduction of turbine pumps following World War II enabled groundwater to be extracted from greater depths and greatly expanded its use. From 1945 to 1953, irrigated acreage grew from 768,000 acres to 1.28 million acres, mostly using groundwater. Meanwhile Arizona's population greatly expanded, from 590,000 in 1945 to 3.67 million in 1990, further increasing water demand.
Colorado River water flowing through the Central Arizona Project represents the last big water development project. Instead of seeking more water, a policy of more efficient management of present supplies has been developed, featuring conservation and reuse.
Issues Summary