Fontana Water Company's water supply is produced from Lytle Creek surface flow, and from wells in the Lytle Basin, Rialto Basin, Chino Basin, and another ground water basin known as No Mans Land. A portion of the water supply is purchased from Cucamonga Valley Water District. Water from the State Water Project is purchased from the Inland Empire Utilities Agency and San Bernardino Valley Municipal Water District.
Lytle Creek surface flow begins at the Intake, located in the Lytle Creek Canyon north of Fontana Water Company's service area. Water from Lytle Creek is diverted into the "upper penstock" pipeline where it flows by gravity to the Afterbay.
The Afterbay, is a diversion facility located immediately downstream from Southern California Edison Company's hydroelectric power plant. Once surface water enters the Afterbay, it is delivered to Fontana Water Company, where it is blended with water from the State Water Project. The water then flows by pipeline to Fontana Water Company's Sandhill Surface Water Treatment Plant for treatment and disinfection before entering the distribution system.
Additionally, Fontana Water Company produces groundwater from 38 wells located in Lytle Basin, Rialto Basin, Chino Basin and No Mans Land.