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23-511: Although it receives some runoff from its local watershed, most of the water is imported via the Mokelumne Aqueduct . The reservoir has a capacity of about 42,000 acre-feet (52,000,000 m), though its normal volume is about 30,250 acre-feet (37,310,000 m). The reservoir name includes "Upper" to distinguish it from Lake Chabot , several miles downstream, which was originally known as "Lower San Leandro Reservoir". The reservoir

46-544: A combined storage capacity of 155,150 acre-feet (0.19137 km ). The water is treated at the San Pablo, Sobrante and Upper San Leandro Treatment Plants before passing through the Claremont Tunnel, which emerges on the western side of the range between Berkeley and Oakland . Water not immediately put into the municipal system is stored in the reservoirs for use in times of low delivery or drought. Most of

69-421: A height of 400 feet (120 m). This would expand the reservoir surface by 33 to 46 feet (10 to 14 m). The enlarged reservoir would cover 3,400 acres (1,400 ha), an increase of 62 percent, and the capacity would be about 300,000 acre-feet (0.37 km ), a roughly 50 percent increase. It would allow for more water to be provided during the dry season that would otherwise have been spilled over

92-463: A population of landlocked rainbow trout whose migration to San Francisco Bay was blocked by the dam. The reservoir is closed to boating and fishing, in order to protect water quality. However, there is a public trail system surrounding the lake. Upper San Leandro Reservoir , engineering details Mokelumne Aqueduct The Mokelumne Aqueduct is a 95-mile (153 km) water conveyance system in central California , United States. The aqueduct

115-536: A single pipeline, were completed. The first deliveries to the Bay Area were made on June 23, 1929. At the time of completion, Pardee Dam was the tallest in the world (this record was surpassed one year later by Diablo Dam in Washington State). In 1949, a second pipeline was built and in 1963 the third pipeline was constructed, bringing the aqueduct to its present capacity. In 1964, the second major dam of

138-655: A southerly direction, terminating near Clay , about 10 miles (16 km) northeast of Lodi . The canal is operated by the U.S. Bureau of Reclamation , as part of the Auburn-Folsom South Unit of the Central Valley Project . It is contracted for irrigation, industrial and municipal water supply; formerly it provided cooling water for the Rancho Seco Nuclear Generating Station . It is also connected to

161-403: A total of $ 25,556,469. The first water delivery was on June 27, 1973, and the canal was completed by the end of 1973. The canal provides water to about 7,000 acres (2,800 ha) of farmland, with $ 12 million in annual revenue. In 1991, water deliveries excluding irrigation amounted to 39,000-acre-foot (48,000,000 m ). The Folsom South Canal Trail, a paved hiking/biking path, runs along

184-508: Is located in a seismically active zone and is considered vulnerable to earthquakes, especially the 15-mile (24 km) stretch where it crosses the Sacramento–San Joaquin Delta, where an earthquake or storm-induced levee failure could damage the pipelines or any of three major river crossings here. A large earthquake (100 year return period or more) could put the aqueduct out of service from 18 months to three years, depending on

207-716: 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 aqueduct is the sole water supply for about 1.4 million people in

230-916: The Central Valley along the Calaveras River before crossing the Sacramento–San Joaquin River Delta . Near Lodi , the aqueduct is joined by an extension of the Folsom South Canal, which supplements the Mokelumne River supply. Once the water reaches the Berkeley Hills above the East Bay, it is channeled into a complex distribution system consisting of six terminal reservoirs ( Briones , Chabot , Lafayette , San Pablo and Upper San Leandro) with

253-498: The Mokelumne Aqueduct , which provides a large portion of the San Francisco Bay Area 's water supply. The trapezoidal concrete canal has an average bottom width of 34 feet (10 m), an average depth of 17.8 feet (5.4 m), and a capacity of 3,500 cubic feet per second (99 m /s). Although it was originally planned to be 69 miles (111 km) long, extending into San Joaquin County , there are currently no plans to construct

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276-477: The East Bay. Under present water rights agreements, EBMUD can withdraw up to 325 million gallons (1,230,000 m ) per day, or 364,000 acre-feet (0.449 km ) per year, from the Mokelumne River. In addition, up to 98 million gallons (371,000 m ) per day or 110,000 acre-feet (0.14 km ) per year can be supplied via a branch from the Sacramento River . However, this supply is expected only to be used in

299-457: The aqueduct consists of three separate buried steel pipelines, although there are also some aboveground segments. The pipelines, also known as Aqueducts No. 1, 2 and 3, have diameters of 61 inches (1.5 m), 67 inches (1.7 m) and 87 inches (2.2 m), respectively. Aside from the main facilities, the distribution system includes 4,000 miles (6,400 km) of pipes, 125 pump plants, and 168 local reservoirs/storage tanks. The aqueduct

322-480: The aqueduct. However, Camanche allows for greater diversions into the aqueduct by storing winter floodwaters spilled from Pardee. During the dry season, water is released from Camanche in order to satisfy local water-rights holders, eliminating the need to draw water from Pardee. The aqueduct travels southwest for 95 miles (153 km) through the western foothills of the Sierra Nevada and then west across

345-709: The dam during the winter. This project would have flooded between 2 and 3 miles (3.2 and 4.8 km) of the Mokelumne River. Due to environmental concerns, the project was shelved in 2011. Folsom South Canal The Folsom South Canal is an aqueduct in Northern California in the United States . The canal diverts water from the American River at Nimbus Dam in Sacramento County and travels about 26.7 miles (43.0 km) in

368-476: The driest 35% of years. In the early 20th century, due to a lack of reliable local water, Bay Area cities began to look to rivers in the Sierra Nevada , about 100 miles (160 km) east, as a potential new source. Although the city of San Francisco was already extending an aqueduct to the Tuolumne River , East Bay communities wanted to build an independent water system, fearing future " hegemony " of

391-508: The extent of the damage. Levee failures in 1980 and 2004 (not caused by earthquakes) on Jones Tract have threatened the aqueduct. An aqueduct joint at the crossing of the Middle River also failed in 1992, nearly causing a washout of the levee. The aqueduct was shut down in time before an actual levee breach could occur. Because Pardee Reservoir is relatively small among California reservoirs, EBMUD has pursued to raise Pardee Dam to

414-602: The project, Camanche Dam , was completed below Pardee. In 1970, EBMUD signed a contract with the U.S. Bureau of Reclamation (USBR) for supplemental water from the Folsom South Canal , which draws water from the American River near Sacramento . The USBR supply was delayed for nearly 40 years in part due to minimum flow requirements in the American River to protect salmon and steelhead populations. The Folsom South Canal Connection (FSCC), which links

437-492: The remaining sections. Construction of the canal began on July 28, 1952, with the excavation of the diversion inlet channel at Nimbus Dam, then also under construction. However, work on the main section of the canal was not begun for almost 20 years. In 1970 and 1971 the Bureau of Reclamation awarded three contracts for Folsom South Canal construction to Syblon-Reid Company, Gordon H. Ball Inc., and Western Contracting Company for

460-418: The two waterways, was finally completed in 2009. The aqueduct begins at Pardee Reservoir, which is formed by Pardee Dam on the Mokelumne River. The reservoir has a capacity of 197,950 acre-feet (0.24417 km ), or about a 10-month supply. Camanche Reservoir, located directly below Pardee, has a storage capacity of 417,120 acre-feet (0.51451 km ) – twice the size of Pardee – but is not directly linked to

483-611: The water system by San Francisco. In 1923, the EBMUD was organized and in 1924 acquired water rights to the Mokelumne River, a major tributary in the San Joaquin River system. On November 4, 1924, residents approved $ 39 million in bonds to finance the project. Construction began in 1926 and by 1929, the 345-foot (105 m) high, concrete arch Pardee Dam and the First Mokelumne Aqueduct, consisting of

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506-402: Was constructed in 1977, directly downstream of the old one, to provide protection against earthquakes. The new dam is 182 feet (55 m) high and 1,300 feet (400 m) long, containing 88,890 cubic yards (67,960 m) of material. Tributaries that flow into the lake include San Leandro , Moraga, King Canyon, Kaiser , Buckhorn and Redwood Creeks. The reservoir and its feeder streams have

529-538: Was originally formed in 1926 when the first San Leandro Dam was completed, and it was first filled by the Mokelumne Aqueduct in 1929. It inundated a long section of the San Leandro Creek valley, including the towns of Valle Vista and Redwood. The original dam was constructed between 1924 and 1926 using the hydraulic fill method and was considered seismically inadequate. A new earth-filled dam

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