Gem Lake
High HazardPoor ConditionEmergency Action Plan: Yes
Location
| State | California |
| County | Mono |
| Nearest City | June Lake |
| River/Stream | Rush Creek |
| Coordinates | 37.75110, -119.14140 |
Physical Characteristics
| Dam Type | Concrete |
| NID Height | 80 ft |
| Dam Height | 80 ft |
| Dam Length | 688 ft |
| Year Completed | 1917 (109 years old) |
Storage & Hydraulics
| NID Storage | 17,228 acre-ft |
| Max Storage | 17,228 acre-ft |
| Normal Storage | 17,228 acre-ft |
| Surface Area | 282 acres |
| Drainage Area | 21 sq mi |
| Max Discharge | 1,700 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Hydroelectric |
| Owner | Southern California Edison Company |
| Owner Type | Private |
| Hazard Classification | High |
| Condition Assessment | Poor |
| Last Inspection | 08/20/2025 |
| Emergency Action Plan | Yes |