The present system of canals was developed by three groups: the ancient Hohokam Indians, the pioneers, and the federal government. Their stories are told below.
Archaeologists believe the Hohokam Indians were peaceful farmers who inhabited the Salt River Valley for about a thousand years, from A.D. 300 to 1450. They are most noted for constructing irrigation ditches with stone hoes.
The Hohokam canal system traversed nearly 500 miles and may have served as many as 50,000 people at a time. The Indians lived here for more than 1,000 years, but left the Valley by about A.D. 1450. Nobody knows exactly why they left.
The Hohokam set the groundwork for today's major canal system, which follows many of the same paths.
The precise locations of all the Hohokam canals are unknown. During the past 100 years, ruined Hohokam villages were plowed under or paved over on both sides of the Salt River from Mesa to Tolleson. By 1920, archaeologists had identified 150 miles of ancient canals, most of which have been destroyed by land development.
Even so, steps have been taken to preserve some Hohokam history. The protected ruins at Pueblo Grande Museum are an example. Located near 44th and Washington streets, Pueblo Grande uses history to show how today's water system developed.
The adobe ruins of the Hohokam baked in the Arizona sun for some 400 years. Then in the 1860s, a central Arizona gold rush brought an influx of non-Indians, including an ex-Confederate cavalryman named Jack Swilling.
Perhaps Swilling noticed the ruined Hohokam canals and thought they could work again. In any event, in December 1867, he formed the Swilling Irrigation and Canal Company at the gold camp at Wickenburg. With 16 others, he intended to take water from the Salt River via a canal so he could grow crops to sell to miners at Wickenburg and the U.S. Cavalry stationed at Ft. McDowell. That waterway became known as Swilling Ditch.
By March 1868, Swilling and his partners had harvested their first crops on land near the present-day Arizona State Hospital. During that same month, a government survey party came to the Valley and noted that a small community calling itself 'Phoenix' had appeared on the scene.
In a short while, the whole area went "canal crazy." Dozens of ditches were started, and some enterprising individuals even tried to make water in canals flow uphill.
The more successful canal projects were the work of private companies and associations, which assessed members a fee for construction and maintenance.
The drought and the U.S. government
The private canal companies and associations existed for about 30 years, and could have lasted longer if nature had cooperated. But a severe drought occurred in the late 1890s and the Salt River did not have enough water to meet the Valley's needs.
At one point, the flow in the river diminished to 25 cubic feet per second (about 187 gallons per second). Thousands of acres of agricultural land went out of production. Orchards withered. Hundreds of people moved away.
For those who remained, the obvious solution was to build a water storage dam to capture spring runoff. Various schemes for financing a dam, including private capitalization and an attempt to sell bonds, were unsuccessful.
Finally in 1902, the National Reclamation Act was passed into law. The Act provided for government loans to 'reclaim' the West with irrigation projects.
While the major effort in Arizona was the Theodore Roosevelt Dam, government engineers also saw the possibilities for improving existing Valley canals and the efficiencies of unifying the canal system. The government purchased all of the private canals, one by one.
The government also built Granite Reef Diversion Dam to replace all of the brush and rock canal headings on the Salt River. (Headings are structures that divert water from the river into a canal.) The north side of the dam delivers water to the Arizona Canal and all the canals on the north side of the river. The south side of the dam provides water to the South Canal and all the canals on the south side of the river.
In 1917, operation of the canal system was turned over to the Salt River Valley Water Users' Association, which still operates the canals for the federal government.