One of two State Water Project aqueducts serving Southern California, the East Branch Aqueduct stores water in Silverwood Lake and Lake Perris.

After being pumped over the Tehachapi Mountains from the Edmonston Pumping Plant, water for the East Branch Aqueduct passes through Palmdale and Lancaster [see also West Branch Aqueduct]. The water is then stored for distribution to Inland Empire cities such as San Bernardino and Riverside.

The East Branch has recently been extended. In 2002, for example, an addition to the aqueduct brought SWP water to Yucaipa, Banning and other communities in the San Gorgonio Pass Water Agency service area. Planning for a second extension is also in development.