Three Mile Reservoir (l.&c.)
High HazardPoor ConditionEmergency Action Plan: Yes
Location
| State | Montana |
| County | Lewis and Clark |
| Nearest City | HELENA VALLEY |
| River/Stream | THREE MILE CREEK |
| Coordinates | 46.69662, -112.18142 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 70 ft |
| Dam Height | 70 ft |
| Dam Length | 470 ft |
| Year Completed | 1926 (100 years old) |
Storage & Hydraulics
| NID Storage | 300 acre-ft |
| Max Storage | 300 acre-ft |
| Normal Storage | 180 acre-ft |
| Surface Area | 3 acres |
| Drainage Area | 5 sq mi |
| Max Discharge | 2,600 cfs |
Ownership & Safety
| Purpose | Irrigation |
| Owner | GRANT WILLIAMS |
| Owner Type | Private |
| Hazard Classification | High |
| Condition Assessment | Poor |
| Last Inspection | 10/20/2021 |
| Emergency Action Plan | Yes |