San Joaquin No. 3 Forebay is an earth dam located in Madera County, California, built in 1906. It carries a Low hazard potential classification and has a fair condition assessment.
Dam profile
NID height · 40 ft40 ft tall and 450 ft long, taller than 86% of U.S. dams with a recorded height. Height is drawn to scale against a two-story house, about 25 ft; the profile is a generic embankment section and the water level is illustrative.
About San Joaquin No. 3 Forebay
The primary purpose of San Joaquin No. 3 Forebay is hydroelectric. The dam generates hydroelectric power by channeling water through turbines, converting the energy of flowing water into electricity. The dam is owned by Pacific Gas and Electric Company (private). It impounds the North Fork Willow Creek near North Fork.
The dam stands 40 feet tall and stretches 450 feet across, creates a reservoir covering 3 acres, and has a maximum storage capacity of 20 acre-feet. Completed in 1906, the structure is over a century old.
This dam has a low hazard potential classification, meaning that failure would cause minimal damage, limited primarily to the dam owner's property, with no expected loss of life. Its condition is rated fair — the dam has minor deficiencies that are being addressed or do not pose an immediate safety threat. The most recent inspection on record was 09/08/2022.
At 40 feet, this dam is taller than 86% of dams nationwide.
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Location
| State | California |
| County | Madera |
| Nearest City | North Fork |
| River/Stream | North Fork Willow Creek |
| Coordinates | 37.25340, -119.53250 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 40 ft |
| Dam Height | 40 ft |
| Dam Length | 450 ft |
| Year Completed | 1906 (120 years old) |
Storage & Hydraulics
| NID Storage | 20 acre-ft |
| Max Storage | 20 acre-ft |
| Normal Storage | 19 acre-ft |
| Surface Area | 3 acres |
| Max Discharge | 170 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Hydroelectric |
| Owner | Pacific Gas and Electric Company |
| Owner Type | Private |
| Hazard Classification | Low |
| Condition Assessment | Fair |
| Last Inspection | 09/08/2022 |
| Emergency Action Plan | Not Required |
Identifiers
| NID ID | CA00339 |
| Federal ID | CA00339 |
| More Info | State Dam Safety Program |