The Cachuma Project, completed in 1953, provides an important source of water to Montecito Water District and other south coast water purveyors. The federally owned facilities include Lake Cachuma (an open surface water reservoir), Bradbury Dam, related infrastructure, and conveyance pipelines.
Water from the Santa Ynez Rivershed is impounded in Lake Cachuma by Bradbury Dam, and this is categorized as a "Surface Supply." The Cachuma Project can provide more than 50% of the District's consumption in average or above-average rainfall years when full allocations are received.
United States Bureau of Reclamation (USBR) constructed and owns the Cachuma Project: USBR Cachuma Project page
Cachuma Project Member Units are the five water agencies participating in the regional use of the Cachuma Project water supply:
1) Montecito Water District
2) City of Santa Barbara
3) Carpinteria Valley Water District
4) Goleta Water District
5) Santa Ynez River Water Conservation District Improvement District No. 1
Member Units have individual contracts with SBCWA that define each water agency’s proportionate share of the Lake Cachuma water supply.
Montecito Water District’s proportionate share of the Cachuma water supply is 10.3%. The District’s available supply from Lake Cachuma during years of normal rainfall is 2,651 acre-feet per year.
Montecito Water District / SBCWA Contract
Cachuma Operations and Maintentance Board (COMB) is the agency responsible for diversion of water from Lake Cachuma to the COMB Member Agencies through the Tecolote Tunnel. In addition COMB operates and maintains the South Coast Conduit pipeline, flow control valves, meters and instrumentation at control stations and turnouts along the South Coast Conduit and at four regulating reservoirs. COMB coordinates closely with the Bureau of Reclamation and Member Units' staff to ensure that water supplies meet daily demands.
Cachuma Conservation Release Board (CCRB) is the agency responsible for the actions and decisions relative to the terms and conditions of the water right permits for Member Units. These include issues related to downstream releases of water from Cachuma Reservoir for the benefit and protection of steelhead/rainbow trout and their habitats, and protection of the Cachuma Project water supply. USBR holds the associated water right permits on behalf of the Member Units.
The dam is located on the Santa Ynez River approximately 30 miles northwest of Montecito. The dam is a zoned earth fill structure that is 279 feet high from the bottom of the cutoff trench to the top of the dam and 206 feet above the streambed. The dam was seismically retrofitted in 2001 and was fitted with flash board extensions to increase the capacity of the lake in 2004.
Original capacity of 205,000 acre-feet at an elevation of 750 feet (NGVD 29 Datum). Per a bathymetric survey conducted in 2013, Lake Cachuma’s capacity has been reduced approximately 21,000 acre-feet due to siltation, with a current capacity of 184,121 acre-feet. While the dam is equipped with flash boards that have raised the maximum elevation to 753 feet with a corresponding capacity of 193,305 acre-feet, this additional storage is dedicated to storing water for fish habitat and does not increase the available water storage for water supply purposes.
Water is diverted from Lake Cachuma through the Tecolote Tunnel, which extends approximately 6.4 miles through the Santa Ynez Mountains to the head works of the South Coast Conduit. The South Coast Conduit is a steel pipeline which runs approximately 26.4 miles and includes four regulating reservoirs - Glen Annie Dam and Reservoir (currently not in service), Lauro Dam and Reservoir, Ortega Dam and Reservoir, and Carpinteria Reservoir. Lake Cachuma water supplies delivered to the South Coast are treated at the City of Santa Barbara Cater Water Treatment Plant.
South Coast Conduit Pipeline and Reservoirs
The South Coast Conduit extends for a distance of approximately 24 miles along the South Coast from Goleta to Carpinteria, and includes four regulating reservoirs. The South Coast Conduit delivers Cachuma Project raw water to the Member Units. Montecito Water District has metered turnouts supplied by the South Coast Conduit. These metered turnouts include; Barker Pass, Office, East Valley, Lambert, Toro Canyon, Sheffield, Asegra Road, Ortega Pump Station Control and County Yard.
Cater Water Treatment Plant
For the District’s Cachuma Project surface water supply (including State Water delivered to Lake Cachuma), the District entered a JPA with the City of Santa Barbara in 1978 for the construction, operation and maintenance of the Cater Water Treatment Plant, a regional water treatment facility serving the City of Santa Barbara, the Carpinteria Valley Water District and the Montecito Water District. The Cater Water Treatment Plant has a production capacity of 37 MGD and is owned and operated by the City of Santa Barbara. The District has a 20% interest in the Cater facility which provides water deliveries daily to meet customer usage at all demand levels. Treated water from the Cater facility is delivered to Montecito through the Cachuma Project South Coast Conduit operated by the Cachuma Operation and Maintenance Board (COMB).
Lake Cachuma is operated based on an operational yield that was developed through experience during long-term droughts and acceptable delivery reductions during such drought periods. The District’s available supply from Lake Cachuma during years of normal rainfall and 100% allocation is 2,651 acre-feet per year.
1921 Montecito County Water District established
1945 Santa Barbara County Water Agency (SBCWA) created
1947 - 1951 Serious drought caused water supply shortages
1950 - 1953 United States Bureau of Reclamation (USBR) constructed the Cachuma Project with the participation of SBCWA, Montecito Water District, and other south coast water suppliers
1956 Cachuma Operation and Maintenance Board (COMB) formed
1950's -1960's The Cachuma Project sufficiently addressed water supply shortages for the south coast water agencies
1973 Cachuma Conservation Release Board (CCRB) formed
1980's Severe drought cycle
1991 Citizen vote to obtain State Project water. Central Coast Water Authority (CCWA) formed
1996 Master Contract between USBR, the Santa Barbara County Water Agency, and the CCWA was renewed for a twenty five-year term
1997 CCWA began State Water deliveries to Lake Cachuma on November 20th
2012-2018 Historic Drought, Lake Cachuma falls to record low levels and Member Units receive low - no allocations depending upon the year
2019 Rainfall replenishes Lake Cachuma to 81% capacity, allocations restored to 100%