Thirtymile Reservoir is a gravity dam located in Blaine County, Montana, built in 1933. It carries a Low hazard potential classification.
Dam profile
NID height · 14 ft14 ft tall and 40 ft long. Height is drawn to scale against a two-story house, about 25 ft; the profile is a generic concrete gravity section and the water level is illustrative.
About Thirtymile Reservoir
The primary purpose of Thirtymile Reservoir is irrigation. The dam stores and diverts water for agricultural irrigation, supporting farming operations in the surrounding area. The dam is owned by Jack Richman (private). It impounds the Thirtymile Creek near Savoy.
The dam stands 14 feet tall and stretches 40 feet across, and has a maximum storage capacity of 55 acre-feet. Completed in 1933, the structure is well-established, with more than 75 years of service.
This dam has a low hazard potential classification, meaning that failure would cause minimal damage, limited primarily to the dam owner's property, with no expected loss of life.
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Location
| State | Montana |
| County | Blaine |
| Nearest City | Savoy |
| River/Stream | Thirtymile Creek |
| Coordinates | 48.51800, -108.74080 |
Physical Characteristics
| Dam Type | Gravity |
| NID Height | 14 ft |
| Dam Height | 14 ft |
| Dam Length | 40 ft |
| Year Completed | 1933 (93 years old) |
Storage & Hydraulics
| NID Storage | 55 acre-ft |
| Max Storage | 55 acre-ft |
| Normal Storage | 55 acre-ft |
Ownership & Safety
| Purpose | Irrigation |
| Owner | Jack Richman |
| Owner Type | Private |
| Hazard Classification | Low |
| Condition Assessment | Not assessed |
| Emergency Action Plan | Not Required |
Identifiers
| NID ID | MT02534 |
| Federal ID | MT02534 |
| More Info | State Dam Safety Program |