Where Your Water Comes From

Local Resources

About half of the Santa Clarita Valley’s (SCV) water is produced by the four retailers from the local groundwater supplies. The groundwater supplies in the Valley come from two sources, the Alluvium Aquifer and the Saugus Formation. The Alluvium Aquifer generally underlies the Santa Clara River and its several tributaries, to maximum depths of about 200 feet; the Saugus Formation underlies practically the entire Upper Santa Clara River area, to depths of at least 2,000 feet.

The State Water Project

State Water Project
About half of the SCV’s water is provided by CLWA from imported water sources, primarily the State Water Project from Northern California.The State Water Project extends for more than 600 miles from north to south terminating at Castaic Lake.

Water is first stored in Lake Oroville, located northeast of Sacramento. At Oroville Dam, water flows through three power plants, then down the Feather and Sacramento Rivers before reaching the Sacramento-San Joaquin Delta.

The Sacramento-San Joaquin Delta is a complex network of natural and man-made channels at the confluence of the Sacramento and San Joaquin rivers near the cities of Sacramento and Stockton. Water makes its way through the Delta to the Harvey O. Banks Pumping Plant where it begins its journey over 300 miles south in the California Aqueduct.

At the A.D. Edmonston Pumping Plant the water is lifted 1,926 feet (one of the highest single lifts in the world) where it enters eight and a half miles of tunnels to cross the Tehachapi Mountains. From this point the water continues south through the West Branch of the California Aqueduct through Quail Lake, Pyramid Lake and finally into Castaic Lake.
Water is withdrawn from Castaic Lake and flows through underground pipelines as large as 244″ in diameter to supply CLWA’s two treatment plants, the Earl Schmidt Filtration Plant and the Rio Vista Water Treatment Plant.

More information on the State Water Project can be obtained from the State Department of Water Resources.

Buena Vista/Rosedale Rio Bravo Water

Buena Vista/Rosedale-Rio Bravo Water Storage District Water Acquisition: CLWA has a water acquisition agreement with the Buena Vista Water Storage District (Buena Vista) and the Rosedale-Rio Bravo Water Storage District (Rosedale-Rio Bravo) in Kern County. Under this Program, high flow Kern River water is captured and recharged into the underlying groundwater basin on an ongoing basis. Buena Vista and Rosedale-Rio Bravo annually deliver 11,000 AF of water to CLWA at the California Aqueduct in Kern County. This water then travels through the State Water Project to Castaic Lake.

Banking Programs

Flexible Storage Accounts: CLWA’s Flexible Storage Accounts permit it to store up to 6,060 AF in Castaic Lake. CLWA must replace any amount above this that it withdraws within five years. CLWA manages this storage by keeping the account full in normal and wet years and then delivering that stored amount (or portion of it) during dry periods. The account is refilled during the following years when adequate SWP supplies are available to CLWA.

Semitropic Water Storage District Banking: CLWA has two existing contracts with the Semitropic Water Storage District in Kern County under which CLWA currently has stored 45,920 acre-feet of water. This water would be delivered to the CLWA when required and is recoverable through 2023.

Rosedale-Rio Bravo Water Storage District Water Banking: CLWA has an existing contract with the Rosedale-Rio Bravo Water Storage District in Kern County under which CLWA has stored 100,000 AF. This stored water will be called upon to meet demands when required.

Exchange Programs

In 2011 CLWA was allocated 80% of the contracted SWP Table A amount and these available supplies exceeded SCV demands. CLWA took the excess water supplies and entered into two-for-one exchange programs with Rosedale Rio-Bravo and West Kern Water District (WKWD). Through these programs, CLWA delivered 24,000 AF and will receive 12,000 AF from these programs through 2021.


Groundwater is water that has percolated into natural, underground aquifers. The Santa Clarita Valley’s groundwater comes from local wells. Some wells are shallow and tap into the Alluvial Aquifer beneath the Santa Clara River and its tributaries. Others draw water from the much deeper Saugus Formation. The groundwater is then disinfected and pumped into the distribution system.

For more information about your local water supply, you can also visit the web sites for your local water retailers.


The Santa Clarita Valley Water Report is an annual report that provides current information about the requirements and water supplies of the Santa Clarita Valley.  You can find SCV Water Reports here.