Phoenix  owes its very existence to the Salt River (or Rio Salado as it is called in Spanish). The snaking stream runs 200 miles from the White Mountains in eastern Arizona to join the Gila River about 15 miles west of downtown Phoenix, and farmers from ancient times to the present have come to the Valley of the Sun for its life-giving water.
A series of dams have left the lower half of the riverbed mostly dry since the first, the Roosevelt Dam, was built in 1911, but the Salt’s natural flow is more than 2,500 cubic feet per second, about three times the amount of water in the Rio Grande. Except for overflow released after storms, most of this water now goes into hundreds of miles of irrigation canals scattered around the region, and the dams themselves provide flood control and produce electricity.
The one exception to this is the 2-mile-long Tempe Town Lake , created in 1999 by building two inflatable dams in the bed of the Salt River and filling the area between them with a combination of upstream storm runoff and treated wastewater. Perhaps not surprisingly, no swimming is allowed, but kayaking, rowing, sailing, and paddle-boating are all popular pastimes, and the lake is stocked with fish regularly.
Central Arizona’s other major river, the Gila, is even longer and more powerful than the Salt. It flows almost 650 miles from the White Mountains near the border with New Mexico all the way to the Colorado River, which forms the border between Arizona and California . Dams and irrigation diversions reduce the river to a trickle in several areas, but in its natural state, the Gila carries more than 6,000 cubic feet of water per second and once was navigable from the Colorado nearly to the New Mexico border. For five years, from the end of the Mexican War to the Gadsden Purchase in 1853, the Gila River actually formed the border between the U.S. and Mexico. Today, significant portions of the river run through Native American communities.
All the dams on the Salt and Gila Rivers have created a surprising number of lakes. An oft-repeated but completely unverified statistic that Arizonans love to repeat is that Maricopa County has one of the highest per capita rates of boat ownership in the nation. Whether or not this is true, the somewhat incongruous sight of a large pickup truck towing a water-ski or fishing boat through the desert is surprisingly common, and it’s possible to learn how to sail, kayak, and even scuba dive at Lake Pleasant and a few of the other large lakes in the area.