Thelma #1
Thelma #1 is an earth dam located in Park County, Montana, built in 1962. It carries a Low hazard potential classification.
About Thelma #1
The primary purpose of Thelma #1 is irrigation. The dam stores and diverts water for agricultural irrigation, supporting farming operations in the surrounding area. The dam is owned by Thelma D. Gray (private). It impounds the Tr-yellowstone River near Emigrant.
The dam stands 19 feet tall and stretches 211 feet across, and has a maximum storage capacity of 106 acre-feet. Completed in 1962, the structure is well into its service life at over 50 years old.
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 | Park |
| Nearest City | Emigrant |
| River/Stream | Tr-yellowstone River |
| Coordinates | 45.24240, -110.86020 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 19 ft |
| Dam Height | 19 ft |
| Dam Length | 211 ft |
| Year Completed | 1962 (64 years old) |
Storage & Hydraulics
| NID Storage | 106 acre-ft |
| Max Storage | 106 acre-ft |
| Normal Storage | 63 acre-ft |
| Max Discharge | 120 cfs |
Ownership & Safety
| Purpose | Irrigation |
| Owner | THELMA D. GRAY |
| Owner Type | Private |
| Hazard Classification | Low |
| Emergency Action Plan | Not Required |
Identifiers
| NID ID | MT00338 |
| Federal ID | MT00338 |
| More Info | State Dam Safety Program |