Upper San Leandro Reservoir
Aerial view of part of the reservoir in 2020
Upper San Leandro Reservoir is located in California
Upper San Leandro Reservoir
Upper San Leandro Reservoir
LocationSan Leandro, California
Coordinates37°46′33″N 122°07′03″W / 37.77583°N 122.11750°W / 37.77583; -122.11750[1]
Primary outflowsSan Leandro Creek
Catchment area21.5 sq mi (56 km2)
Managing agencyEast Bay Municipal Utility District
First flooded1926
Max. length6 mi (9.7 km)
Surface area620 acres (250 ha)
Water volume42,000 acre⋅ft (52,000,000 m3)[2]
Surface elevation459 ft (140 m)[1]

Upper San Leandro Reservoir is an artificial lake in Alameda County and Contra Costa County, California which provides water for the East Bay Municipal Utility District (EBMUD). It is impounded by the earth-filled San Leandro Dam on San Leandro Creek, located at the southeast end of the lake.

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 m3),[2] though its normal volume is about 30,250 acre-feet (37,310,000 m3).[3] The reservoir name includes "Upper" to distinguish it from Lake Chabot, several miles downstream, which was originally known as "Lower San Leandro Reservoir".

Original dam

The reservoir was originally formed in 1926 when the first San Leandro Dam was completed, and it was first filled by the Mokelumne Aqueduct in 1929.[4] 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.[5]

New dam

Dam constructed in 1977, with the spillway toward the left. The earth-filled dam is green because it is covered with grass.
Spillway constructed in 1977
Aerial view with several branches of the reservoir

A new earth-filled dam was constructed in 1977, directly downstream of the old one, to provide protection against earthquakes.[6] The new dam is 182 feet (55 m) high and 1,300 feet (400 m) long, containing 88,890 cubic yards (67,960 m3) of material.[2]

Tributaries that flow into the lake include San Leandro, Moraga, King Canyon, Kaiser, Buckhorn and Redwood Creeks.[7] The reservoir and its feeder streams have a population of landlocked rainbow trout whose migration to San Francisco Bay was blocked by the dam.[8]

The reservoir is closed to boating and fishing, in order to protect water quality. However, there is a public trail system surrounding the lake.[6]

See also

References

  1. 1 2 "Upper San Leandro Reservoir". Geographic Names Information System. United States Geological Survey, United States Department of the Interior. 1981-01-19. Retrieved 2017-01-11.
  2. 1 2 3 "National Performance of Dams Database". Stanford University. Retrieved 2017-01-12.
  3. ↑ "Upper San Leandro". California Data Exchange Center. California Department of Water Resources. Retrieved 2017-01-12.
  4. ↑ "History". East Bay Municipal Utility District. Retrieved 2017-01-12.
  5. ↑ Jansen, R.B. (1988). Advanced Dam Engineering for Design, Construction, and Rehabilitation. Springer Science & Business Media. pp. 247–249. ISBN 0-44224-397-9.
  6. 1 2 "Chapter 4.8 Hydrology and Water Quality". San Leandro Shoreline Development Draft EIR. City of San Leandro. Retrieved 2017-01-12.
  7. ↑ "San Leandro Creek Watershed". Alameda County Flood Control and Water Conservation District. Retrieved 2017-01-11.
  8. ↑ Mariscal, Alicia (2003-05-13). "San Leandro Creek Watershed - Focusing on the Lower Watershed beyond the Chabot Reservoir" (PDF). San Francisco State University. Retrieved 2017-01-12.

Upper San Leandro Reservoir, engineering details

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