Calleguas was formed in 1953 to provide supplemental water supply to southern Ventura County. The district is governed by an elected, five-member Board of Directors and employs 80 full-time staff. Calleguas is a member agency of Metropolitan Water District of Southern California and provides wholesale water service to 19 member purveyors, serving a population of 640,000. Throughout the 365 square mile service area, Calleguas operates and maintains reservoirs, groundwater injection wells, pump/pressure regulating stations, hydroelectric generators, and 140 miles of large diameter pipeline.