O`Shaughnessy
California, Tuolumne County, Tuolumne River
Location
| State | California |
| County | Tuolumne |
| River | Tuolumne River |
| Coordinates | 37.94840, -119.78900 |
Physical Characteristics
| NID Height | 312 ft |
| Dam Height | 312 ft |
| Dam Length | 900 ft |
| NID Storage | 360,000 acre-ft |
| Max Storage | 360,000 acre-ft |
| Surface Area | 1,972 acres |
Safety Classification
| Hazard Potential | High |
| Condition Assessment | Satisfactory |
| EAP Status | Yes |
| Last Inspection | October 6, 2025 |
| Inspection Frequency | 1 |
Dam Information
| Year Completed | 1923 |
| Primary Purpose | Water Supply |
| Dam Type | Gravity |
| Owner Type | Local Government |
| Owner | San Francisco Public Utilities Commission |
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.