ABSTRACT
The Phoenix Metropolitian Area, the fastest growing community in the USA, is located in a semiarid region with mean annual precipitation of 180mm. Its water supply consists of limited surface water from two watersheds and groundwater. Overdraft of the regional aquifer is the result of several decades of extensive agriculture and more recently rapid urbanization. In the late 1980s Colorado River Water imported via the Central Arizona Project Aqueduct was added to the water supply. This included the development of aquifer storage facilities since new surface storage was not physically, economically nor environmentally feasible. A large underground storage facility was constructed in partnership by all the municipalities of the area. It has operated successfully since 1994, banking surplus water for future use and improving the management of peak water demands.
