Clifton Court Forebay is an earth dam located in Contra Costa County, California, built in 1970. It carries a Low hazard potential classification and has a satisfactory condition assessment.
Dam profile
NID height · 34 ft34 ft tall and 39,000 ft long, taller than 78% 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 Clifton Court Forebay
Clifton Court Forebay is a dam in Contra Costa, California. The dam is owned by California Department of Water Resources (state). It impounds the Tr Old River.
The dam stands 34 feet tall and stretches 39,000 feet across, creates a reservoir covering 2,500 acres, and has a maximum storage capacity of 29,000 acre-feet. Completed in 1970, the structure is well into its service life at over 50 years 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 satisfactory, indicating no existing or potential dam safety deficiencies are recognized. The most recent inspection on record was 08/05/2025.
At 34 feet, this dam is taller than 78% of dams nationwide.
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Location
| State | California |
| County | Contra Costa |
| River/Stream | Tr Old River |
| Coordinates | 37.82100, -121.58640 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 34 ft |
| Dam Height | 34 ft |
| Dam Length | 39,000 ft |
| Year Completed | 1970 (56 years old) |
Storage & Hydraulics
| NID Storage | 29,000 acre-ft |
| Max Storage | 29,000 acre-ft |
| Surface Area | 2,500 acres |
Ownership & Safety
| Purpose | Other |
| Owner | California Department of Water Resources |
| Owner Type | State |
| Hazard Classification | Low |
| Condition Assessment | Satisfactory |
| Last Inspection | 08/05/2025 |
| Emergency Action Plan | No |
Identifiers
| NID ID | CA00050 |
| Federal ID | CA00050 |
| More Info | State Dam Safety Program |