Central Arizona Project (CAP) is Arizona's single largest resource for renewable water supplies. CAP is designed to bring about 1.5 million acre-feet of water from the Colorado River to Central and Southern Arizona every year. More than 5 million people, or more than 80% of the state's population, live in Maricopa, Pima and Pinal counties, where CAP water is delivered. CAP carries water from Lake Havasu near Parker to the southern boundary of the San Xavier Indian Reservation southwest of Tucson. It is a 336-mile long system of aqueducts, tunnels, pumping plants and pipelines and is the largest single resource of renewable water supplies in Arizona.