This article needs additional citations for verification. (April 2015) |
Cogswell Dam is a rockfill dam on the West Fork of the San Gabriel River in Los Angeles County, California. It is located in the San Gabriel Mountains, northeast of Mount Wilson, and within the Angeles National Forest.
| Cogswell Dam | |
|---|---|
 Satellite view | |
  Location of Cogswell Dam in California | |
| Country | United States |
| Location | San Gabriel Mountains, Angeles National Forest, Los Angeles County, California |
| Coordinates | 34°14′41″N 117°57′55″W / 34.24472°N 117.96528°W |
| Opening date | 1935 |
| Owner(s) | Los Angeles County Department of Public Works |
| Dam and spillways | |
| Type of dam | Rock-filled |
| Impounds | West Fork San Gabriel River |
| Height | 266 ft (81 m) |
| Height (foundation) | 280 ft (85 m)[1] |
| Length | 585 ft (178 m) |
| Spillway capacity | 59,900 cu ft/s (1,700 m3/s)[1] |
| Reservoir | |
| Creates | Cogswell Reservoir |
| Total capacity | 12,234 acre⋅ft (15,090,000 m3) |
| Catchment area | 38.4 sq mi (99 km2) |
| Surface area | 146 acres (59 ha) |
It forms Cogswell Reservoir, which has a capacity of 8,969 acre-feet (11,063,000 m3).[2]
The dam serves mainly for flood control in conjunction with San Gabriel Dam and Morris Dam downstream. San Gabriel Dam lies 13 miles (21 km) downstream.[3]
Construction
editBonds for the dam's construction were issued in 1924. Construction began in March 1932 and was completed in April 1934, at a total cost of US$3,127,762.[3]
The rock-fill dam, built by the Los Angeles County Flood Control District, is 585 feet (178 m) long, 266 feet (81 m) tall (measured from the stream bed), 18 feet (5.5 m) wide at the top, and contains 1,044,945 cubic yards (798,918 m3) of material. Its crest is 2,412 feet (735 m) above sea level and 27 feet (8.2 m) above the certified water storage elevation.[2]
The dam rests on crystalline granite bedrock. The buttress is 750 feet (230 m) thick at the base, and the height from foundation to crest is 285 feet (87 m). There are concrete cutoff walls and a concrete facing slab on the dam's upstream side.[3]
See also
editReferences
edit- ^ a b [1] [dead link]
- ^ a b "Dams Within the Jurisdiction of the State of California (A-G)" (PDF). California Department of Water Resources. Archived from the original (PDF) on 2012-03-09. Retrieved September 30, 2012.
- ^ a b c "Cogswell Dam" (PDF). Dpwftp.cp.la.ca.us. Retrieved November 18, 2012.[permanent dead link]