Mammoth Reservoir
California — Placer County — Offstream
Location
| State | California |
| County | Placer |
| River | Offstream |
| Coordinates | 38.81860, -121.13900 |
Physical Characteristics
| NID Height | 23 ft |
| Dam Height | 23 ft |
| Dam Length | 2,360 ft |
| NID Storage | 103 acre-ft |
| Max Storage | 103 acre-ft |
| Surface Area | 11 acres |
Safety Classification
| Hazard Potential | High |
| Condition Assessment | Satisfactory |
| EAP Status | Yes |
| Last Inspection | September 24, 2025 |
| Inspection Frequency | 1 |
Dam Information
| Year Completed | 1851 |
| Primary Purpose | Other |
| Dam Type | Earth |
| Owner Type | Local Government |
| Owner | Placer County Water Agency |
Location Map
About This Dam Record
Dam safety data is maintained by the Army Corps of Engineers National Inventory of Dams (NID). High-hazard dams are those where failure could cause loss of life or major property damage downstream.