Extraction
Roughly 25% of the District's water supply is obtained from imported surface water that originates from northern California and is transported via the State Water Project's California Aqueduct to Lake Silverwood in the San Bernardino mountains. This water is extracted from the lake and directed to the Rialto Feeder, a large pipeline, owned by Metropolitan Water District of Southern California, that travels along the foothills, delivering water to area surface water treatment plants.
Treatment
The Water Facilities Authority (WFA) Agua de Lejos Treatment Plant in Upland treats the surface water to meet drinking water standards and then distributes it to its member agency owners - Monte Vista Water District and the cities of Chino, Chino Hills, Ontario and Upland.