Water Supply

Water is a vital resource to Santa Barbara County. The availability, quality and cost of water in this area have greatly influenced the economy and the community. Like other areas with limited water supplies, county residents must manage resources carefully and supplement local supplies with water from other regions. County water sources are diverse and the facilities and programs established to manage those supplies are complex. To understand more about the unique hydrology of our county, see a map of average county rainfall, view current and historic rainfall and reservoir trends, and read the 2020 Water Year Santa Barbara County Hydrology Report.  

County residents obtain their water from several sources: groundwater withdrawal, storm runoff collected in local reservoirs, the State Water Project, and recycled water. The county's potable water supply is delivered to the public through a variety of water purveyors: incorporated cities, community service districts, water districts, public utility companies, conservation districts and others.

For more information on water supply issues in the county, click on the links below.
Local Streams and Reservoirs
State Water Project
Recycled Water
Web links


Groundwater is the water found in the spaces between gravel, sand, silt, and clay in areas where water accumulates to form aquifers. Rain which reaches the earth's surface can penetrate the ground and slowly make its way downward through the soil before reaching an impermeable layer, such as clay or rock. Groundwater use varies greatly by region but makes up about 30% of California's annual water supply in normal years and up to 60% in drought years.


Groundwater pump near Buellton                                                                        Diagram of groundwater storage

Local Streams and Reservoirs

Surface water found in streams and reservoirs is often a vital component to water supplies for domestic use. Development of reservoirs can reduce the threat of flooding and store stream runoff until it is needed; allowing society to use water from winter rains to meet our needs during the dry summer and fall months when streams cannot meet demand. Locally, the Jameson, Gibraltar, and Cachuma reservoirs on the Santa Ynez River help meet the needs of communities on the South Coast and helps supplement groundwater supplies in the Santa Ynez River downstream. Twitchell reservoir on the Sisquoc River helps reduce threats from floods and replenishes groundwater important to agriculture in the Santa Maria Valley.

Cachuma_snow_photo Gibraltar_reservoir

Cachuma Reservoir                                                                                                      Gibraltar Reservoir 

Jameson_reservoir  Twitchell_photo

Jameson Reservoir                                                                         Twitchell Reservoir

State Water Project

First raised as a concept in 1919, the initial approval of funding in 1960 by California voters for the State Water Project (SWP) now includes 34 storage facilities and over 700 miles of canals and pipelines. Water is delivered from Northern California rivers through the California Bay-Delta into the San Joaquin Valley, where water is used irrigate 750,000 acres of farmland with the remainder pumped to Southern California. Capable of storing 5.8 million acre-feet of water, the SWP meets a portion of the water supply for over 25 million Californians. In 1991, voters in Santa Barbara approved a local extension of the SWP following a multiyear drought, resulting in the Coastal Branch which serves San Luis Obispo and Santa Barbara County. While droughts have caused less than full deliveries of SWP in recent years, the importance of these deliveries on California's economy cannot be underestimated. For more information, watch the City of Santa Barbara's informational video, " State Water Project":


Map of the State Water Project's Coastal Branch 

Recycled Water

Water recycling (or water reclamation) involves treating municipal wastewater to remove sediments and impurities for reuse. While not used as a source for drinking water, recycled water reduces reliance on increasingly scarce and expensive surface water and can minimize groundwater overdraft (extracting more water than is replenished.) Further, recycled water is a local, drought-resistant supply. Currently, the City of Santa Barbara and Goleta Water District distribute recycled water through a separate 'purple pipe' system dedicated to landscape use at select parks, schools, and commercial businesses. While not supplying recycled water directly to landscape uses, the City of Santa Maria uses their treated wastewater to help recharge groundwater supplies. 

Recycled_water_plant recycld_water_sign2

The Santa Barbara Tertiary Treatment Facility                                             Recycled water sign on an irrigated planter in Santa Barbara


Purple pipes near the Santa Barbara Airport (Photo credit: Goleta Water District) 


The City of Santa Barbara Charles Meyer Desalination Facility was built in 1991-1992 as a temporary emergency water supply in response to the severe drought of 1986-1991. Between 1991 and 2015 the plant remained on "long-term storage mode," until water demand could not be met through other supplies. On July 21, 2015, in response to severe drought conditions, the Santa Barbara City Council voted to reactivate the plant and it began delivering water to Santa Barbara residents again in May 2017. Designed to filter ocean water in order to generate potable drinking water, the facility is authorized by the California Coastal Commission to produce a maximum of 10,000 AFY. To learn more about the City of Santa Barbara's desalination project, watch their video, " Santa Barbara Desalination Plant: The Supply Nearby." 


The Charles Meyer Desalination Facility

Web Links

Central Coast Water Authority
DWR Groundwater Information Center
South Coast Water Sources 
State Water Project 
Local Water Providers