Surface Water
Prior to the mid 1980s, Scottsdale relied almost entirely on groundwater for its water supply. Today, about 90 percent of our drinking water comes from two surface water sources: the Central Arizona Project and the Salt River Project.
Central Arizona Project
About two-thirds of Scottsdale’s water supply comes from the Central Arizona Project (CAP) – a 336-mile-long system of aqueducts, tunnels, pumping plants and pipelines designed to bring about 1.5 million acre-feet of Colorado River water per year to water users in Pima, Pinal and Maricopa counties. CAP carries water from Lake Havasu near Parker to the southern boundary of the San Xavier Indian Reservation southwest of Tucson.
Scottsdale began using CAP water in 1987 and our CAP allocation for 2015 is approximately 81,000 acre-feet. CAP water is treated at the 70 million gallon a day CAP Water Treatment Plant, located at the Water Campus in north Scottsdale.
Get the latest information on the Colorado River shortage
Salt River Project
In 1903, Arizona settlers formed the Salt River Valley Water Users Association (Salt River Project) and pledged more than 200,000 acres of their land as collateral for a government loan to build a water storage and delivery system. They used this loan to build Roosevelt dam. As Phoenix grew, SRP added three more dams on the Salt River and two dams on the Verde River.
Scottsdale's SRP supplies are delivered through the Arizona Canal to the city’s Chaparral Water Treatment Plant, located near the intersection of McDonald Drive and Hayden Road. The 30 million gallon a day capacity plant has been in operation since the spring of 2006. The total SRP supply available to Scottsdale in normal supply years is 16,894 acre feet per year.
Unlike other sources of supply, which can be used anywhere within the Scottsdale service area, SRP supplies are available only to certain parts of the city, referred to as "on-project" lands. Scottsdale’s on-project land is south of the Arizona Canal.