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> Water & Wastewater | | | Top l Gibraltar Reservoir l Devil’s Canyon l Cachuma Project l Mission Tunnel l Ground Water l Recycled Water l State Water Project l Desalination l Top
Gibraltar Reservoir
Description
Constant radius, concrete arch dam (shown below) located on the Santa Ynez River, 8 miles north of Santa Barbara; owned by City of Santa Barbara; constructed 1913-22, with an original capacity of 14,500 AF; raised to current elevation in 1949; strengthened in 1990-91; water is delivered through the Santa Ynez Mountains to Santa Barbara via Mission Tunnel. Drainage Area: 216 square miles
Maximum Normal Water Surface Elevation: 1,400' above sea level Annual Yield: Average of approximately 4,600 AFY
Current Capacity: 7,264 Acre Feet (per 1998 Bathymetric Study) Operating Criteria
Diversions are limited by the 1930 Gin Chow legal judgment and the 1989 Upper Santa Ynez River Operations Agreement (USYROA, also known as the "Pass Through Agreement") which incorporates a compromise regarding the interpretation of Gin Chow. The agreement requires the City to track the difference between spills under actual operating conditions and under a "base" scenario (a hypothetical reservoir equal to the 1986 area/capacity profile). A basic goal of the agreement is to allow the City to maximize yield from Gibraltar while preventing impacts on the Cachuma Project and other downstream interests. Two modes of operation ("mitigation" and "pass through") are defined in the agreement. "Mitigation" mode requires the City to declare a maximum annual Gibraltar diversion level of up to 8,000 AFY and to mitigate the reduction in the average long-term annual yield of the downstream Cachuma Project (if any) that is estimated to result from that level of diversion. Mitigation is by relinquishment of a portion of the City's Cachuma Project entitlement. Diversions must conform to a monthly schedule. The City is currently in the mitigation mode with a declared diversion level of 5,000 AFY requiring mitigation of 67 AFY. The "pass through" mode allows the City to take a portion of its allowable Gibraltar diversions via the Cachuma Project, to the extent that spills at Gibraltar Dam exceed the amount of spills that would have occurred under the "base" scenario. The "pass through" mode is intended to be useful as the capacity of Gibraltar is reduced by siltation. Cost Information
Costs for this source of supply are primarily "sunk" or fixed costs, including the original cost of construction, plus a cost of $9 million for strengthening in 1990-91, plus the cost of Mission Tunnel. Variable costs for Gibraltar water consist of the marginal cost of treatment at Cater Treatment Plant which is approximately $50/AF.
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Devil's Canyon Creek
 Description: The City maintains a small diversion works on Devil's Canyon Creek below Gibraltar Dam which diverts water from Devil's Canyon Creek into Mission Tunnel. Annual Yield
Average: 115 AFY
Range: 24 AFY - 557 AFY Operating Criteria
Water is diverted as available to help improve the quality of water going into Mission Tunnel. Diverted water is counted as a part of allowable diversions under the Pass Through Agreement. Cost Information
Variable costs are the same as Gibraltar water, or approximately $50/AF. | | Top l Gibraltar Reservoir l Devil’s Canyon l Cachuma Project l Mission Tunnel l Ground Water l Recycled Water l State Water Project l Desalination l Top
Cachuma Project
Description
Earth filled dam (Bradbury Dam, shown below) located on the Santa Ynez River 25 miles northwest of Santa Barbara; owned and operated by U.S. Bureau of Reclamation; constructed early 1950's; interim seismic retrofit completed 1996, permanent repairs expected to be completed in 2001; water is delivered through the Santa Ynez Mountains to the South Coast via 6.4 mile Tecolote Tunnel, 24.3 mile South Coast Conduit, and four regulating reservoirs, completed in 1956. Cachuma Project Member Units
City of Santa Barbara
Goleta Water District
Montecito Water District
Carpinteria Valley Water District
Santa Ynez River Water Conservation District, Improvement Dist. No. 1
Drainage Area: 417 square miles (including Gibraltar drainage area)
Maximum Normal Water Surface Elevation: 750' above sea level
Annual Yield: The current total project operational yield equals 25,714 AFY, based on acceptable shortage of up to 20% during dry years. The City's share is 32.19% or 8,277 AFY.
Current Capacity: 190,409 AF (preliminary bathymetric update suggests 188,035 AF)
Operating Criteria
The project operates under a permit granted by the State Water Resources Control Board (SWRCB). The current Water Right 94-5 continues earlier requirements for releases to protect downstream interests and requires a hearing in the year 2000 to address outstanding issues related to potential project impacts on vegetation, fish, and downstream users. The hearing has commenced and will continue into 2001. Project water is accumulated to the extent that inflow is not needed to satisfy the release requirements. It is delivered to the member units in accordance with a Master Contract between U.S. Bureau of Reclamation, and the Santa Barbara County Water Agency and the Cachuma Project Authority. The contract was renewed in 1996 for a twenty five-year term. Cost Information
The water supply contract with the U.S. Bureau of Reclamation sets the unit cost of the City's share of project yield at $120/AF for a total annual cost of approximately $993,000. Since this cost is treated as a payback of capital cost, it is not considered a variable cost. Variable costs are the same as for Gibraltar ($50/AF) since the water is treated at Cater Treatment Plant. Costs for permanent seismic repairs at Bradbury Dam are estimated at $30 million. The federal government is expected to pay 85% of this cost with the balance paid by project members. The City's share is estimated at $1.5 million. | | Top l Gibraltar Reservoir l Devil’s Canyon l Cachuma Project l Mission Tunnel l Ground Water l Recycled Water l State Water Project l Desalination l Top
Mission Tunnel
Description
A 3.7 mile tunnel through the Santa Ynez Mountains running from the North Portal, located approximately 1,700 feet downstream of Gibraltar Dam to the South Portal, located on Mission Creek approximately 3 miles north of downtown Santa Barbara; constructed 1904-1911; rehabilitation work completed December 1994 Annual Infiltration
For the period of 1976 through 2000, infiltration ranged from 520 AFY to 2,172 AFY, with an average of 1,348 AFY Operating Criteria
Tunnel infiltration augments water conveyed from Gibraltar Reservoir, normally flowing to Cater Treatment Plant via the penstock, hydroelectric facility, and Lauro Reservoir. A portion of this combined flow is sometimes diverted to Mission Creek for groundwater recharge purposes. Cost Information
Variable costs are the same as Gibraltar water or approximately $50/AF. The 1994 Mission Tunnel rehabilitation project was completed at a cost of $761,000.
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Groundwater
Description
Groundwater is produced from three groundwater basins: Storage Unit 1 (in the vicinity of downtown), the Foothill Basin (upper State Street area), and Storage Unit 3 (located generally in the Westside area). The current rough estimate of usable storage volume is approximately 16,000 AF. Groundwater recharge is augmented through releases to Mission Creek and through injection capability at two production wells. Groundwater modeling capabilities have been substantially improved through use of the Multiple Objective Optimization Model (MOOM) developed by USGS. MOOM is a computer model that evaluates the City's water supply system for optimal operating scenarios. Perennial Yield
Perennial yield is the amount of water that can be pumped from the basins on a continual basis without causing overdraft. The portion of the perennial yield available to the City from all three units is approximately 1,400 AFY. Long-term average annual pumping has been estimated at 1,304 AFY under the LTWSP. Operating Criteria
Groundwater is pumped to replace surface supplies lost to drought. During periods of ample surface supplies, groundwater is allowed to recharge naturally and by means of artificial recharge when space is available in the basin and when not precluded by pumping done as a part of the clean up of groundwater contamination. Maximum pumping capacity is approximately 5,500 AFY, though poor water quality and threat of seawater intrusion reduces this capacity somewhat, and replacement wells are planned. A pumping capacity of 4,500 AFY is the target for meeting long-term supply requirements. Cost Information
Variable costs for ground water production are approximately $150/AF. Capital expenditures of approximately $500,000 for new production and injection wells are anticipated in coming years.
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Recycled Water
Description
The City initiated planning for a water reclamation project in the early 1980's. Phase I distribution was completed in 1989. It included addition of tertiary treatment with carbon filtration and disinfection at El Estero Wastewater Treatment Plant, a 600,000 gallon distribution reservoir and pumping station, and 5.1 miles of distribution main. Phase II was completed in 1992, adding an additional pumping station, a 1.5 million gallon reservoir and 8.3 miles of distribution main. The system now provides recycled water to 432 acres of landscaped area at 40 sites, such as parks, schools, golf courses, and other large landscaped areas. (Santa Barbara Golf Club, one of the larger users, is shown above.) Several park restrooms have been retrofitted to use recycled water for toilet flushing. Water is provided at 80% of the potable water irrigation rate as an incentive for using recycled water and to compensate for additional irrigation requirements associated with salt leaching. The City is conducting ongoing monitoring of recycled water quality and salt levels in the soil. Annual Capacity
The system has the capacity to treat and deliver 1,200 AFY; current demand is approximately 800 AFY. Future Uses
Optimization of the use of recycled water has been mostly accomplished with the completion of Phase II. Distribution pipelines have been constructed to all cost effective use areas, and most existing potential user sites are now connected. Industrial uses of recycled water, such as concrete mixing, are being investigated, as is additional dual plumbing of park restrooms. New development in proximity to the recycled water main is required to utilize recycled water for landscape irrigation. Known projects include a major waterfront park and hotel project, expansion of a major regional recreational facility at Las Positas Park, and a potential new school site in the Hidden Valley area. Projects such as these are expected to allow the City to make use of most of the 1,200 AFY capacity by the end of the planning period. Operating Criteria
Recycled water is a non-variable supply in that it can only be supplied to those customers that are connected to the recycled water system. Usage is relatively constant regardless of drought conditions. Potable water is sometimes blended with recycled water as a means of maintaining acceptable recycle water quality. Cost Information
The variable cost for producing recycled water is approximately equal to the $50/AF treatment cost at Cater Treatment Plant, since it involves essentially the same process. Distribution pumping costs add approximately $40/AF. The capital cost for the construction of Phases I and II was approximately $15.2 million. The unit cost, including amortized capital costs and variable costs, is approximately $1,450/AF.
El Estero Wastewater Treatment Plant
More Recycled Water Information
WateReuse Association (For information on recycled water in general)
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State Water Project
Oroville Dam: Primary storage of State Water Project
http://www.water.ca.gov/maps/allprojects.cfm Description
The City is a participant in the State Water Project and can now receive State Project water via the 102 mile Coastal Branch of the State Aqueduct and the 42-mile Santa Ynez Extension ending at Lake Cachuma. Construction was completed in 1997. When needed, water will be delivered from Cachuma through Tecolote Tunnel along with Cachuma Project water. Annual Yield
The City's entitlement is 3,000 AFY, subject to availability. An additional 10% drought buffer provides some insurance against shortages. Average long-term deliveries have been estimated at 2,566 AFY, assuming requests for full deliveries each year. Annual deliveries are projected to range from 870 AFY to 3,000 AFY. A recent court decision generated renewed attention to the SWP. Negotiated in the mid 1990's, the "Monterey Amendments" are a series of amendments to the State Water Contracts by which State Water is provided to participating contractors. The amendments constitute a compromise among urban and agricultural participants that increases flexibility in the use of State Water and reduces controversy associated with the manner in which shortages are handled. The recent appellate court decision determined that the environmental document on the amendments was not adequate and that there were procedural problems with the preparation. A further appeal to the California Supreme Court is anticipated. The substantive issue in the case has to do with whether agencies planning on the use of State Water have adequately assessed the reliability of this water supply source, given State Water Project entitlements of 4.1 million AFY and safe yield of roughly half that amount with existing water storage facilities. The issue is referred to as concern about approving development based on "paper water," or water that exists as entitlement that may not be available during droughts. The City's "critical drought year" approach to water supply planning insures that supply targets can be met in the worst case, not just the average case. Supplies from the State Water Project were modeled using conservative assumptions from the California Department of Water Resources. Despite the fact that the critical periods for local water supplies did not coincide with the critical period for State Water Project deliveries, State Water deliveries were discounted to 50% of entitlement during the local critical year to account for the potential for simultaneous north-south droughts. For added conservatism, the modeling assumptions made no use of the 10% of additional "drought buffer" entitlement available to all Santa Barbara County participants and assumed no purchase of additional water from the State Water Bank to make up for deficiencies in State Water Project deliveries. Finally, the LTWSP as a whole includes a safety margin of 10% to account for unplanned shortages in supply or increases in demand. Given the above, the City has planned adequately for shortages from the State Water Project. Operating Criteria
State Project water is ordered annually on an as-needed basis to replace local surface supplies lost to drought. Little or no deliveries are expected to be requested in the near term, except as necessary to replace local surface supplies lost to drought. The pipeline will be utilized to take advantage of available water supplies via the State Water Bank or through independent purchases of temporary entitlement to firm up deliveries during drought. Cost Information
The variable costs for State Water are approximately $224/AF, plus the treatment cost of $50/AF at Cater Treatment Plant. For deliveries of State Water Bank water, or other surplus water, an additional acquisition cost of approximately $150/AF is expected. The total project capital costs include costs for the State portion and the local (CCWA) portion of the project. The State portion capital cost is estimated at $461 million, of which 93% is allocated to Santa Barbara County participants. The City's share is 7.0% of the total cost, or approximately $32 million. The local portion, including the pipeline from Vandenberg Air Force Base to Lake Cachuma and the Regional Treatment Plant at Polonio Pass, has a capital cost of approximately $119 million, with a City share of 13.3%, or approximately $16 million. The unit cost, including amortized capital costs and variable costs, is approximately $1,500/AF. California Department of Water Resources, State Water Project
Central Coast Water Authority Home Page
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Desalination
Description
The City constructed a reverse osmosis seawater desalination facility (shown below) as an emergency water supply during the drought of 1990. The facility has since been incorporated into the City's long-term supply plan as a way of reducing shortages due to depleted surface supplies during drought. Two neighboring water purveyors participated in the temporary project, but have since dropped out of the project. A portion of the reverse osmosis filtration capacity was subsequently sold, leaving a current capacity of 3,125 AF. In 1995, the plant was dedicated as the Charles Meyer Desalination Facility in honor of Commissioner Meyer's long and dedicated service on the City Water Commission. Annual Capacity
With the departure of the co-participants and sale of a portion of the capacity, the desalination facility now has a production capacity of 3,125. Operating Criteria
Relatively high variable costs for desalination make this supply the last to be utilized during periods of shortage. The facility is normally in long-term storage mode and is expected to be recommissioned when the demand (less a maximum acceptable shortage of 10%) cannot be met using all of the other available supplies. As an alternative operating mode, desalted water could be produced during non-drought periods for exchange with other water purveyors throughout the State via the State Water Project. Cost Information
Variable costs for desalination are estimated at $1,100/AF based on the water supply contract between the City and Ionics, Inc. under which the facility was constructed. The capital cost for construction was $34 million. The unit cost at full production, including capital costs (amortized over a 20-year period) and variable costs, is approximately $1,500/AF. Savings of variable costs accrue during periods that desalination in not needed.
American Membrane Technology Association.
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Water Efficiency Improvements
The City regards improved water efficiency by customers as a source of supply, because water saved by increasing efficiency is available to supply our customers. In its most recent long-term supply plan, the City targeted 1,500 AFY of water savings from improved efficiency. Many cost-effective ways to improve water efficiency are available, including high efficiency plumbing fixtures, water-efficient landscaping, and state-of-the-art irrigation systems. Go to the conservation page for more information. | |
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