Porta Reservoir No. 2 is an earth dam located in Roosevelt County, Montana, built in 1963. It carries a Significant hazard potential classification.
Dam profile
NID height · 22 ft22 ft tall and 3,600 ft long. Height is drawn to scale against a two-story house, about 25 ft; the profile is a generic embankment section and the water level is illustrative.
About Porta Reservoir No. 2
The primary purpose of Porta Reservoir No. 2 is recreation. The dam creates a reservoir used for recreational activities such as fishing, boating, and swimming. The dam is owned by N. Porta (private). It impounds the Lake Creek near Medicine Lake.
The dam stands 22 feet tall and stretches 3,600 feet across, has a maximum storage capacity of 114 acre-feet, and collects water from a drainage area of 31 square miles. Completed in 1963, the structure is well into its service life at over 50 years old.
This dam has a significant hazard potential classification, meaning that a failure could cause significant economic damage — flooding roads, bridges, or property downstream — but is not expected to result in loss of life.
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Location
| State | Montana |
| County | Roosevelt |
| Nearest City | Medicine Lake |
| River/Stream | Lake Creek |
| Coordinates | 48.36590, -104.19070 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 22 ft |
| Dam Height | 22 ft |
| Dam Length | 3,600 ft |
| Year Completed | 1963 (63 years old) |
Storage & Hydraulics
| NID Storage | 114 acre-ft |
| Max Storage | 114 acre-ft |
| Normal Storage | 114 acre-ft |
| Drainage Area | 31 sq mi |
Ownership & Safety
| Purpose | Recreation |
| Owner | N. Porta |
| Owner Type | Private |
| Hazard Classification | Significant |
| Condition Assessment | Not assessed |
| Emergency Action Plan | Not Required |
Identifiers
| NID ID | MT01216 |
| Federal ID | MT01216 |
| More Info | State Dam Safety Program |