Calaveras Reservoir
| Calaveras Reservoir[1] | |
|---|---|
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| Location | Santa Clara / Alameda counties, California, USA |
| Coordinates | 37°28′43″N 121°49′21″W / 37.4785°N 121.8226°WCoordinates: 37°28′43″N 121°49′21″W / 37.4785°N 121.8226°W |
| Lake type | Reservoir |
| Primary inflows | Arroyo Hondo Calaveras Creek |
| Catchment area | 98.4 sq mi (255 km2) |
| Basin countries | United States |
| Surface area | 1,450 acres (590 ha) |
| Water volume | 100,000 acre·ft (120,000,000 m3) |
| Surface elevation | 234 m (768 ft) |
| References | U.S. Geological Survey Geographic Names Information System: Calaveras Reservoir |
Calaveras Reservoir is a lake located primarily in Santa Clara County, California with a small portion and its dam in Alameda County, California. The reservoir has a capacity of 100,000 acre·ft (120,000,000 m3). In Spanish, Calaveras means "skulls."
Calaveras Dam, which creates the reservoir, used to be the largest earth-fill dam in the world. It is 210 feet (64 m) and was completed in 1925. The city and county of San Francisco owns the dam and reservoir.
Poverty Ridge and Oak Ridge lie to the east of Calaveras Reservoir, Milpitas and Monument Peak lie to the west, Sunol lies to the far north, and Calaveras Creek and Los Buellis Hills lie to the south.
Calaveras Reservoir is fed mainly by Arroyo Hondo and Calaveras Creek. Lying in the Calaveras Valley, the region is a geologically active area with the Calaveras Fault parallel to, and to the west of, the Dam site. Roads adjacent to the reservoir include Calaveras Road and Marsh Road, the latter which gained significant public attention due to a murder which occurred there in the early 1980s.
The Calaveras Valley is rich and diverse in wildlife. Some of the most common animals include deer, coyotes, squirrels, turkey vultures, red-winged blackbirds, yellow-billed magpies, red-tailed hawks, brewer's blackbirds, purple martins, barn swallows, bullock's orioles, and warblers. These have recently been joined by a nesting pair of bald eagles.[citation needed]
In the 19th century, the Calaveras Valley which the reservoir now fills was primarily an agricultural region known for its production of hay, strawberries, and tomatoes. Because of San Francisco's increasing demand for drinking water at the turn of the 20th century, the farmers in the region were forced to sell their land to the Spring Valley Water Company, which in turn sold it to the San Francisco Water Company. Although the first dam that was constructed collapsed due to engineering flaws, another dam was soon built. The flooding of the Calaveras Valley rapidly changed its sensitive hydrology and natural environment. The reservoir is reported to contain a very large population of largemouth bass, rainbow trout and other species. However, fishing here is illegal.
Today, the San Francisco Public Utilities Commission (SFPUC) owns 36,000 acres (150 km²) in the Alameda Creek Watershed. Some lands in the watershed are leased to livestock companies for cattle ranching to control vegetation and prevent fires. Most of the land is closed to the public because of concerns over drinking water safety and quality.
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[edit] Dam Replacement
Because the dam is located near a seismically active fault zone and was determined to be seismically vulnerable, the California Department of Water Resources, Division of Safety of Dams (DSOD) has limited since 2001 the amount of water that can be stored in the reservoir to approximately 30 percent of its former full storage capacity (full storage capacity is 96,850 acre feet (119,460,000 m3) of water) until the safety deficiencies are corrected.
The San Francisco Public Utilities Commission plans to construct a new dam of equal height downstream of the existing dam as part of the $4.3 billion Water System Improvement Program. The 7 year-long environmental impact study report was certified by the San Francisco City Planning Commission on January 27, 2011. Later that day, the $434 Million Calaveras Dam Replacement Project was given the green light by the SFPUC. Construction is anticipated to begin in the Spring of 2011.[2]
The replacement effort will include several measures to aid in the restoration of native fish populations. However, construction of a fish ladder to provide Steelhead trout (Oncorhynchus mykiss) access to the waters above the dam was deemed infeasible because at 290 feet (88 m), it would be the tallest fish ladder in the country and cost $40 million. Steelhead trout have not had access to spawning streams above Calaveras Dam since it was built in 1925.[3] However, environmentalists won concessions from the SFPUC to assure adequate water releases from the new dam to improve summer flows as well as a smaller fish ladder around a diversion dam blocking access to upper Alameda Creek, which is regarded as prime trout habitat.[4]
[edit] Plane Crash Discovery
A drought swept California in the late 1980s and early 1990s, and water reservoirs throughout the state reported record low water levels. Maintenance work on Calaveras Reservoir, in conjunction with the drought, had lowered the water 100 feet (30 m) by January 1991. And as the water dropped, the shiny aluminum of a wrecked plane poked through the mud of the reservoir.
Near the wrecked plane, on January 5, 1991, two skeletons were found. Using old medical and dental records, as well as the serial number on the plane's engine (a 4-cylinder, 75 horsepower (56 kW) Continental), the remains were positively identified by the county sheriff office as being that Clifford Gillman and Robert Louviere, missing since June 16, 1963. The bodies were removed but the wreckage is still present in the middle of the reservoir.[5]
[edit] See also
[edit] References
- ^ http://cdec.water.ca.gov/cgi-progs/profile?s=PNF&type=dam
- ^ http://sfwater.org/detail.cfm/MC_ID/18/MSC_ID/114/C_ID/5372
- ^ "Calaveras Dam Project Revised, Future Operations Could Help Restore Alameda Creek". Alameda Creek Alliance. 2011-01-25. http://www.alamedacreek.org/Press_Releases/Calaveras%20Dam%20Revisions%201-25-11.pdf. Retrieved 2011-02-02.
- ^ Kelly Zito (2011-01-28). "Calaveras Dam rebuilding projected approved". San Francisco Chronicle. http://www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2011/01/28/BASP1HF8J9.DTL. Retrieved 2011-02-02.
- ^ http://www.check-six.com/Crash_Sites/N3770H-CalaverasResErcoupe.htm
- Loomis, Patricia. Milpitas: A Century of Little Cornfields
