The Metropolitan Water District of Southern California is a cooperative of more than 25 cities and water agencies that serve over 18 million people in nearly six counties in the United States. The district imports water from the Colorado River and Northern California to supplement local supplies, and help its members to develop increased water conservation, recycling, storage and other resource-management programs. It delivers nearly 1.7 billion gallons of water annually to a 5,200-square-mile service area. The Metropolitan Water District of Southern California s member agencies include the Calleguas Municipal Water District, Municipal Water District of Orange County and the Upper San Gabriel Valley Municipal Water District. It is located in Riverside, Calif.