The Carlsbad Municipal Water District currently imports all of its drinking water supply. Imported water originates hundreds of miles away from the Colorado River through the Colorado River Aqueduct, and from Northern California through the California Aqueduct (also known as the State Water Project). Water from these sources is imported and treated by the Metropolitan Water District of Southern California at its Lake Skinner Treatment Plant in Riverside County and the San Diego County Water Authority at its Twin Oaks Valley Water Treatment Plant in San Marcos.
After rigorous treatment and meeting all regulatory requirements, the water travels through San Diego County Water Authority owned pipelines and is purchased and distributed by the Carlsbad Municipal Water District to its customers. Each year, the water district delivers drinking water to nearly 86,000 people through 447 miles of pipelines.