Cogswell Reservoir, located in San Gabriel, California, is a rockfill dam completed in 1935 for the primary purpose of flood risk reduction.
Wind
Humidity
With a dam height of 266 feet and a storage capacity of 8,969 acre-feet, Cogswell Reservoir plays a crucial role in managing water resources in the region. Owned and regulated by the local government, the dam is also used for hydroelectric power generation, irrigation, and water supply, highlighting its versatility and importance in the area.
Despite its satisfactory condition assessment and high hazard potential, Cogswell Reservoir undergoes regular inspections and enforcement to ensure its safety and reliability. The dam is state-regulated and permitted, with a history of meeting guidelines and maintaining emergency preparedness. With the Wfk San Gabriel River flowing through its vicinity, Cogswell Reservoir serves as a vital infrastructure for water management and climate resilience in Los Angeles County. As a significant feature in the region's water landscape, Cogswell Reservoir underscores the intersection of water resource management and environmental stewardship.
Year Completed |
1935 |
Dam Length |
585 |
Dam Height |
266 |
River Or Stream |
Wfk San Gabriel R |
Primary Dam Type |
Rockfill |
Surface Area |
146 |
Hydraulic Height |
239 |
Drainage Area |
38.4 |
Nid Storage |
8969 |
Hazard Potential |
High |
Nid Height |
266 |
| Location | Reservations | Toilets |
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Glenn Camp
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Glenn Camp Campground (Hike or bike in 7 miles)
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Spring Camp Campground
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Spring Camp
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Devore
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Devils Cyn
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Gaging Station Below Spillway Of Cogswell Dam (Ne 1/4, Se 1/4, Sec 19, T2N, R10W) To Confluence With Nf San Gabriel River (Sw 1/4.Sw 1/4, Sec 15, T2N, R9W)
Cooper Canyon- Near State Highway 2 (Sw 1/4, Ne 1/4, Sec 16, T3N, R10W To Confluence With Little Rock Creek
North Fork - Confluence Of Soldier And Coldbrook Creeks (Se1/4,Sw1/4, Sec) 5, T2N,,R9W To Conflluence With West Fork Of San Gabriel (Sw 1/4,Sw1/4, Sec 17, T2N, R8W)
West Fork - Headwaters (Se 1/4, Ne 1/4, Sec 14, T2N, R12W) To Cogswell Reservoir (Ne 1/4, Sw 1/4, Sec 24, T2N, R9W
Mainstream - Confluence With Cooper Canyon To Confluence Wit South Fork Little Rock Creek
Mainstream - Headwaters To Confluence With Cooper Canyon