Moccasin Ler
Moccasin Ler is an earth dam located in Tuolumne County, California, built in 1930. It carries a High hazard potential classification and has a fair condition assessment.
About Moccasin Ler
Moccasin Ler is a dam in Tuolumne, California. The dam is owned by San Francisco Public Utilities Commission (local government). It impounds the Moccasin Creek near N/a.
The dam stands 60 feet tall and stretches 720 feet across, creates a reservoir covering 29 acres, has a maximum storage capacity of 554 acre-feet, and collects water from a drainage area of 25 square miles. Completed in 1930, the structure is well-established, with more than 75 years of service.
This dam carries a high hazard potential classification, which means that a failure or uncontrolled release of water would likely cause loss of human life. This classification reflects the consequences of failure, not the likelihood — it indicates that people live or work in the area downstream. Its condition is rated fair — the dam has minor deficiencies that are being addressed or do not pose an immediate safety threat. An emergency action plan is in place for this dam. The most recent inspection on record was 02/05/2025.
At 60 feet, this dam is taller than 95% of all dams in the United States.
Living Downstream
If you live or work downstream of this dam, consider taking these steps: learn your local evacuation routes, check whether your county emergency management office has a dam failure inundation map, and sign up for local emergency alerts. The California dam safety program can provide more specific information about emergency planning for this structure.
Search for dams near your address to see all dams in your area with hazard classifications and safety data.
Location
| State | California |
| County | Tuolumne |
| Nearest City | N/a |
| River/Stream | Moccasin Creek |
| Coordinates | 37.81230, -120.30570 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 60 ft |
| Dam Height | 60 ft |
| Dam Length | 720 ft |
| Year Completed | 1930 (96 years old) |
Storage & Hydraulics
| NID Storage | 554 acre-ft |
| Max Storage | 554 acre-ft |
| Surface Area | 29 acres |
| Drainage Area | 25 sq mi |
Ownership & Safety
| Purpose | Other |
| Owner | San Francisco Public Utilities Commission |
| Owner Type | Local Government |
| Hazard Classification | High |
| Condition Assessment | Fair |
| Last Inspection | 02/05/2025 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | CA00122 |
| Federal ID | CA00122 |
| More Info | State Dam Safety Program |