|San Luis Dam|
|Location||Merced County, California|
|Owner(s)||U.S. Bureau of Reclamation and California Department of Water Resources|
|Dam and spillways|
|Type of dam||Embankment|
|Height (foundation)||382 ft (116 m)|
|Length||18,600 ft (5,700 m)|
|Dam volume||77,656,000 cu yd (59,372,000 m3)|
|Creates||San Luis Reservoir|
|Total capacity||2,041,000 acre⋅ft (2.518 km3)|
|Catchment area||82.6 sq mi (214 km2)|
|Surface area||12,700 acres (5,100 ha)|
|Normal elevation||544 ft (166 m)|
|William R. Gianelli Powerplant|
|Hydraulic head||323 ft (98 m) max|
|Turbines||8 x 53.0 MW Francis turbines|
|Installed capacity||424 MW|
San Luis Dam (also known as B.F. Sisk Dam, after Bernie Sisk) is a major earth-filled dam in Merced County, California, which forms San Luis Reservoir, the largest off-stream reservoir in the United States. The dam and reservoir are located in the Diablo Range to the east of Pacheco Pass and about 10 miles (16 km) west of Los Banos. San Luis Dam, a jointly-owned state and federal facility, stores more than 2 million acre feet (2.5 km3) of water for the California State Water Project and the federal Central Valley Project. Although the dam is located in the valley of San Luis Creek, the majority of its water comes from man-made aqueducts which are supplied from other rivers in Northern California.
San Luis provides water mainly for irrigation in the San Joaquin Valley, where it augments the supply for more than 1 million acres (400,000 ha) of agricultural land, although some water is also used for urban and environmental uses. The dam was built between 1963 and 1968, and filled for the first time in 1969. It provides flexibility to the state water system by capturing, via pumps and canals, the wet season (November–April) runoff that would otherwise flow from the Sacramento–San Joaquin River Delta into the Pacific Ocean. It also generates hydroelectricity by releasing the water when it is needed. However, it has indirectly impacted the environment by enabling increased water diversion from sensitive estuary regions. In recent years, a combination of drought and pumping restrictions enacted to protect endangered fish have contributed to low water levels at the San Luis Reservoir.
The dam and reservoir are visible from the Romero Overlook Visitors Center, which is located along Highway 152.
San Luis Reservoir is designed to capture excess runoff flowing out of the Sacramento–San Joaquin River Delta, the largest watershed of California, during the winter and spring rainy season so it can be used during the dry season. This water includes both natural river flows, and water that is evacuated from Shasta Lake, Lake Oroville, Folsom Lake and other reservoirs for flood control purposes. This is accomplished via a system of canals and pumping stations which divert water from the Delta and deliver it south to water users.
The San Luis Dam, a zoned compacted earthfill structure, is one of the largest embankment dams in the United States, with a structural height of 382 feet (116 m), a length of 18,600 feet (5,700 m) and a structural volume of 77,656,000 cubic yards (59,372,000 m3). When full, San Luis Reservoir is more than 300 feet (91 m) deep, covers 12,700 acres (5,100 ha), and contains 2,041,000 acre-feet (2.518 km3) of water. The storage capacity of San Luis Reservoir is divided with 55 percent belonging to the state and 45 percent to the federal government.
The Delta-Mendota Canal, originally built in 1951, carries irrigation water for the federal Central Valley Project (CVP) operated by the U.S. Bureau of Reclamation to supply San Joaquin Valley farms. The California Aqueduct was built in 1968 as part of the State Water Project (SWP), to deliver water to Los Angeles and other cities and farmlands in Southern California. Both canals begin at the Clifton Court Forebay near Tracy, California where the Jones and Banks Pumping Plants draw water from the Delta in order to deliver it south. The canals are linked to O'Neill Forebay, a small reservoir located directly in front of San Luis Dam where the water is temporarily stored for distribution. Most CVP project water is dedicated to irrigation while the SWP water supply is split, with 30 percent going to agriculture and 70 percent to urban areas.
The San Luis Pumping-Generating Plant (also known as the William R. Gianelli Power Plant) is situated between O'Neill and San Luis Reservoirs and can pump water uphill for storage in San Luis during period of low demand, and release it during periods of high demand. The plant has eight reversible Francis turbine units which can generate up to 424 megawatts when releasing water. The power consumption while pumping is 376 megawatts. The maximum water flow while generating is 13,120 cubic feet per second (372 m3/s), and maximum pumping is 11,000 cubic feet per second (310 m3/s).
The sale of peaking power lowers the overall cost of operating the State Water Project, particularly the giant electric pumps along the California Aqueduct. A short 230 kV power line heads eastward to deliver this electricity to Northern California's electricity backbone, Path 15. percent of the energy can be recouped when the water is discharged.However, due to friction losses when pumping water uphill, only about 70
The valley now filled by the San Luis Reservoir was originally inhabited by the Yokuts people; during the early 19th century it was part of Rancho San Luis Gonzaga and small-scale agriculture began in the area, supplied by groundwater and canals from the San Joaquin River. The Central Valley Project was begun in the 1930s to provide an additional water supply to the area and greatly expanded the irrigated acreage. However, the lack of local water storage limited the system's flexibility.During the dry summer months when surface water was frequently unavailable, farmers pumped vast volumes of groundwater to irrigate their crops, considerably depleting the regional aquifer. The Bureau of Reclamation recognized the need for a large storage reservoir in order to provide a year-round water supply, and began studies for this project in 1955.
During the 1950s the State of California also began building its own water project, whose design also required an off-stream water storage reservoir. The state approached the federal government with an offer to design a joint-use facility; however it took several years for the Bureau of Reclamation to agree to the proposal. On May 16, 1960 the state and the Bureau of Reclamation signed a "coordinated operation" agreement which laid out plans for the construction of joint-use facilities, including the San Luis Dam and Power Plant. percent of the cost with the federal government providing the rest. On June 3, 1960 President Dwight D. Eisenhower signed an act authorizing the San Luis Unit Project.The state government was to cover 55
Plans for the dam were completed by 1961 and the groundbreaking ceremony took place on August 18, 1962. In front of a crowd of 15,000 people, President John F. Kennedy and California Governor Pat Brown gave the signal to detonate the first explosive charges in the San Luis dam site. Work began the same month to reroute Pacheco Pass Highway (today's SR 152) around the future reservoir basin. The primary contract for the dam itself was awarded to Morrison-Knudsen, Utah Construction & Mining Co., and Brown & Root in 1963 for $85.9 million. Alfred M. Petrofsky held the role of chief engineer.
Construction of San Luis Dam lasted from 1963 to early 1968. The dam was constructed in several zones with quarried local earth and rock averaging as much as 130,000 cubic yards (99,000 m3) per day. The 100-ton Caterpillar dump trucks used during construction were, at the time, the largest in the US. The construction of the four water intake towers, each 284 feet (87 m) high, involved the first use of tower cranes in the US. The work force peaked at 2,304 in October 1965 and declined thereafter; in January 1968, with construction almost completed, the first water was delivered through the California Aqueduct to begin filling the giant reservoir. The dam was officially dedicated on April 20, 1968 by Secretary of the Interior Stewart L. Udall. However, it was not until May 31, 1969 when San Luis Reservoir filled for the first time.
In 1981, during low water conditions in San Luis Reservoir, a 1,100-foot (340 m) long segment of the upstream face of the dam partially collapsed, causing 400,000 cubic yards (310,000 m3) of material to fall into the reservoir. Since the reservoir was at a low level the dam was in no immediate danger of failure, however it could not be safely refilled until the damage was repaired. By August 1982, the area had been stabilized with 1,400,000 cubic yards (1,100,000 m3) of additional fill (known as a "buttressing berm"), at a cost of $6.1 million. In July 1984 another crack appeared in the dam, but it soon stabilized. No such incidents have occurred since this one.
Most of the water stored behind San Luis Dam is used for irrigation. The CVP share of the water is released down the Delta-Mendota Canal into the San Joaquin River, which provides water for 380,000 acres (150,000 ha) of farmland in the central part of the San Joaquin Valley. Parts of the CVP and SWP water supply the Westlands Water District of Fresno and Kings Counties, which irrigates up to 735,000 acres (297,000 ha) of land on the west side of the San Joaquin Valley. Prior to the construction of San Luis Dam and the joint use portion of the California Aqueduct (the San Luis Canal) this area depended entirely on groundwater. In 2016 the main crops grown here were almonds, tomatoes, pistachios and wheat. Most of the Westlands district consists of large corporate farms totaling hundreds if not thousands of acres. The SWP also provides more than 980,000 acre-feet (1.21 km3) of water per year for farmers in Kern County.
San Luis Reservoir stores water for the Metropolitan Water District of Southern California (MWD) which is one of the primary providers of water for the Greater Los Angeles Area. This water reaches Southern California via the East and West Branches of the California Aqueduct.It also provides water for the Central Coast cities like San Luis Obispo and Santa Barbara via the Coastal Branch of the California Aqueduct. Local water agencies and irrigation districts are allowed to "bank" water in San Luis Reservoir for later use, by purchasing it during the rainy season at lower prices when it is not immediately needed. However, regulations only allow such carryover storage when San Luis is not full, since state and federal water takes priority. Once the reservoir fills, any carryover water that has not been used is effectively "lost", i.e. transferred to the CVP and SWP supplies.
In addition to supplying the main CVP and SWP canals, San Luis Reservoir also supplies water to the Santa Clara Valley via the Pacheco Tunnel and Hollister Conduit, which travel under the Diablo Range. At the western end of the tunnel, the water is stored behind San Justo Dam, an earthfill dam completed in 1986. These facilities are all part of the San Felipe Division of the Central Valley Project.
The San Luis & Delta-Mendota Water Authority represents the 29 federal water contractors served by the San Luis Unit, consisting of a combined 2,100,000-acre (850,000 ha) service area in the San Joaquin and Santa Clara Valleys. The Authority operates the Federally owned portion of the San Luis Reservoir and water supply infrastructure.
Before San Luis Dam was built, most of the pumping from the Delta occurred during the summer when there is high demand for irrigation. The construction of San Luis Dam enabled the additional capture of winter flows that would otherwise be lost to the sea. However, water pumping during certain times of the winter and early spring interfere with fish migration, notably the Sacramento River chinook salmon. The pumping changes the primary direction of water flow in the Delta from east-west to north-south, confusing the fish. As a result, certain environmental restrictions have been in place since the 1990s to limit pumping during the spring chinook run (March–April). This has led to frequent low water levels at San Luis Reservoir; in late summer 2016 it fell to 10 percent of capacity, the lowest since 1991.
These restrictions have been criticized by water agencies as too stringent, especially since California is in a long-term drought. During winter 2016 at least 180,000 acre-feet (220,000,000 m3) of water was allowed to drain from the Delta into the Pacific instead of being pumped into San Luis Reservoir. In December 2016, Congress passed a bill allowing increased water pumping during times when fish are not at high risk. This will generally allow more water to be stored at San Luis Reservoir. The bill will require daily monitoring of fish to ensure environmental laws are not violated, instead of relying on hard limits which may not match current conditions. California Senator Dianne Feinstein remarked that "the goal... is to run California's water system based on good science, not intuition."
In 2013, the Bureau of Reclamation proposed raising the San Luis Dam by 20 feet (6.1 m) to create about 130,000 acre-feet (160,000,000 m3) of extra storage capacity. An expanded reservoir could store more water in wet years to compensate for less water being pumped in dry years due to environmental restrictions. The project would cost $360 million and would also involve seismic upgrades to protect the dam from earthquakes. The dam expansion is one of several major water projects that could be funded, in part, by a $2.7 billion bond measure approved by California voters in 2014.
The Central Valley Project (CVP) is a federal power and water management project in the U.S. state of California under the supervision of the United States Bureau of Reclamation (USBR). It was devised in 1933 in order to provide irrigation and municipal water to much of California's Central Valley—by regulating and storing water in reservoirs in the northern half of the state, and transporting it to the water-poor San Joaquin Valley and its surroundings by means of a series of canals, aqueducts and pump plants, some shared with the California State Water Project (SWP). Many CVP water users are represented by the Central Valley Project Water Association.
Shasta Dam is a concrete arch-gravity dam across the Sacramento River in Northern California in the United States. At 602 feet (183 m) high, it is the eighth-tallest dam in the United States. Located at the north end of the Sacramento Valley, Shasta Dam creates Shasta Lake for long-term water storage, flood control, hydroelectricity and protection against the intrusion of saline water. The largest reservoir in the state, Shasta Lake can hold about 4,500,000 acre-feet (5,600 GL).
The Kesterson National Wildlife Refuge was an artificial wetland environment, created using agricultural runoff from farmland in California's Central Valley.
New Melones Dam is an earth and rock filled embankment dam on the Stanislaus River, about 5 miles (8.0 km) west of Jamestown, California, United States, on the border of Calaveras County and Tuolumne County. The water impounded by the 625-foot (191 m)-tall dam forms New Melones Lake, California's fourth largest reservoir, in the foothills of the Sierra Nevada east of the San Joaquin Valley. The dam serves mainly for irrigation water supply, and also provides hydropower generation, flood control, and recreation benefits.
The Delta–Mendota Canal is a 117-mile-long (188 km) aqueduct in central California, United States. The canal was designed and completed in 1951 by the U.S. Bureau of Reclamation as part of the Central Valley Project. It carries freshwater to replace San Joaquin River water which is diverted into the Madera Canal and Friant-Kern Canal at Friant Dam.
Friant Dam is a concrete gravity dam on the San Joaquin River in central California in the United States, on the boundary of Fresno and Madera Counties. It was built between 1937 and 1942 as part of a U.S. Bureau of Reclamation (USBR) water project to provide irrigation water to the southern San Joaquin Valley. The dam impounds Millerton Lake, a 4,900-acre (2,000 ha) reservoir about 15 miles (24 km) north of Fresno.
The California Department of Water Resources (DWR) is part of the California Natural Resources Agency and is responsible for the management and regulation of the State of California's water usage. The department was created in 1956 by Governor Goodwin Knight following severe flooding across Northern California in 1955, where they combined the Division of Water Resources of the Department of Public Works with the State Engineer's Office, the Water Project Authority, and the State Water Resources Board. It is headquartered in Sacramento.
Trinity Dam is an earthfill dam on the Trinity River located about 7 miles (11 km) northeast of Weaverville, California in the United States. The dam was completed in the early 1960s as part of the federal Central Valley Project to provide irrigation water to the arid San Joaquin Valley.
The San Luis Reservoir is an artificial lake on San Luis Creek in the eastern slopes of the Diablo Range of Merced County, California, approximately 12 mi (19 km) west of Los Banos on State Route 152, which crosses Pacheco Pass and runs along its north shore. It is the fifth largest reservoir in California. The reservoir stores water taken from the San Joaquin-Sacramento River Delta. Water is pumped uphill into the reservoir from the O'Neill Forebay which is fed by the California Aqueduct and is released back into the forebay to continue downstream along the aqueduct as needed for farm irrigation and other uses. Depending on water levels, the reservoir is approximately nine miles long from north to south at its longest point, and five miles (8 km) wide. At the eastern end of the reservoir is the San Luis Dam, or the B.F. Sisk Dam, the fourth largest embankment dam in the United States, which allows for a total capacity of 2,041,000 acre-feet (2,518,000 dam3). Pacheco State Park lies along its western shores.
The California State Water Project, commonly known as the SWP, is a state water management project in the U.S. state of California under the supervision of the California Department of Water Resources. The SWP is one of the largest public water and power utilities in the world, providing drinking water for more than 23 million people and generating an average of 6,500 GWh of hydroelectricity annually. However, as it is the largest single consumer of power in the state itself, it has a net usage of 5,100 GWh.
Westlands Water District is a water district in central California, a local-government entity formed in 1952, that holds long-term contracts for water supplied by the Central Valley Project and the California State Water Project.
The Friant-Kern Canal is a 152 mi (245 km) aqueduct managed by the United States Bureau of Reclamation in Central California to convey water to augment irrigation capacity in Fresno, Tulare, and Kern counties. A part of the Central Valley Project, canal construction began in 1949 and was completed in 1951 at a cost of $60.8 million.
California's interconnected water system serves over 30 million people and irrigates over 5,680,000 acres (2,300,000 ha) of farmland. As the world's largest, most productive, and potentially most controversial water system, it manages over 40 million acre-feet (49 km3) of water per year.
O'Neill Dam is an earthfill dam on San Luis Creek, 12 miles (19 km) west of Los Banos, California, United States, on the eastern slopes of the Pacific Coast Ranges of Merced County. Forming the O'Neill Forebay, a forebay to the San Luis Reservoir, it is roughly 2.5 miles (4.0 km) downstream from the San Luis Dam.
The Mokelumne Aqueduct is a 95-mile (153 km) water conveyance system in central California, United States. The aqueduct is supplied by the Mokelumne River and provides water to 35 municipalities in the East Bay in the San Francisco Bay Area. The aqueduct and the associated dams, pipelines, treatment plants and hydroelectric system are owned and operated by the East Bay Municipal Utility District (EBMUD) and provide over 90 percent of the water used by the agency.
The Sites Reservoir is a proposed $5.2-billion offstream reservoir project west of Colusa in the Sacramento Valley of northern California, to be built by the California Department of Water Resources. The project would pump 470,000 to 640,000 acre-feet per year of the winter flood flow from the Sacramento River upstream of the Sacramento–San Joaquin River Delta, through existing canals to an artificial lake 14 miles (23 km) away. Annual yield will depend on precipitation and environmental restrictions.
The Sacramento-San Joaquin Valley Emergency Water Delivery Act is a bill that tries to address the severe California drought. The bill would change some environmental regulations and stop or delay a project designed to restore a dried up section of the San Joaquin River. The bill was considered highly partisan and there are disputes over how much it would solve the water problem, or even intended to solve it, as opposed to an election year ploy unlikely to pass Congress.
California Water Fix and Eco Restore, formerly known as the Bay Delta Conservation Plan, is a $15 billion plan proposed by Governor Jerry Brown and the California Department of Water Resources to build two large, four-story tall tunnels to carry fresh water from the Sacramento River under the Sacramento-San Joaquin Delta toward the intake stations for the State Water Project and the Central Valley Project.
The Delta Cross Channel is a facility in California's Sacramento-San Joaquin Delta that diverts water from the Sacramento River. The facility was built in 1951 in Walnut Grove, California.
Red Bluff Diversion Dam is a disused irrigation diversion dam on the Sacramento River in Tehama County, California, United States, southeast of the city of Red Bluff. Until 2013, the dam provided irrigation water for two canals that serve 150,000 acres (61,000 ha) of farmland on the west side of the Sacramento Valley. The dam and canals are part of the Sacramento Canals Unit of the Central Valley Project, operated by the U.S. Bureau of Reclamation. In 2013, the dam was decommissioned and the river allowed to flow freely through the site in order to protect migrating fish. A pumping plant constructed a short distance upstream now supplies water to the canal system.
|Wikimedia Commons has media related to San Luis Reservoir .|