O`shaughnessy
High HazardSatisfactory ConditionEmergency Action Plan: Yes
Location
| County | Tuolumne |
| Nearest City | Waterford |
| River/Stream | Tuolumne River |
| Coordinates | 37.94840, -119.78900 |
Physical Characteristics
| Dam Type | Gravity |
| NID Height | 312 ft |
| Dam Height | 312 ft |
| Dam Length | 900 ft |
| Year Completed | 1923 (103 years old) |
Storage & Hydraulics
| NID Storage | 360,000 acre-ft |
| Max Storage | 360,000 acre-ft |
| Surface Area | 1,972 acres |
| Drainage Area | 459 sq mi |
Ownership & Safety
| Purpose | Water Supply |
| Owner | San Francisco Public Utilities Commission |
| Owner Type | Local Government |
| Hazard Classification | High |
| Condition Assessment | Satisfactory |
| Last Inspection | 10/06/2025 |
| Emergency Action Plan | Yes |