Upper Oso
California — Orange County — Oso Creek
Location
| State | California |
| County | Orange |
| River | Oso Creek |
| Coordinates | 33.65970, -117.63200 |
Physical Characteristics
| NID Height | 142 ft |
| Dam Height | 142 ft |
| Dam Length | 800 ft |
| NID Storage | 3,700 acre-ft |
| Max Storage | 3,700 acre-ft |
| Surface Area | 115 acres |
Safety Classification
| Hazard Potential | High |
| Condition Assessment | Satisfactory |
| EAP Status | Yes |
| Last Inspection | April 3, 2025 |
| Inspection Frequency | 1 |
Dam Information
| Year Completed | 1979 |
| Primary Purpose | Water Supply |
| Dam Type | Earth |
| Owner Type | Public Utility |
| Owner | Santa Margarita Water District |
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.