Decock #3 is an earth dam located in Treasure County, Montana, built in 1949. It carries a Low hazard potential classification.
Dam profile
NID height · 15 ft15 ft tall and 250 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 Decock #3
The primary purpose of Decock #3 is fire protection, stock, or small fish pond. The dam maintains a small impoundment used for fire suppression, livestock watering, or as a fish pond. The dam is owned by Decock Ranch Co (private). It impounds the Tr-yellowstone River near Hysham.
The dam stands 15 feet tall and stretches 250 feet across, has a maximum storage capacity of 193 acre-feet, and collects water from a drainage area of 4 square miles. Completed in 1949, 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 | Treasure |
| Nearest City | Hysham |
| River/Stream | Tr-yellowstone River |
| Coordinates | 46.31524, -107.34689 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 15 ft |
| Dam Height | 15 ft |
| Dam Length | 250 ft |
| Year Completed | 1949 (77 years old) |
Storage & Hydraulics
| NID Storage | 193 acre-ft |
| Max Storage | 193 acre-ft |
| Normal Storage | 99 acre-ft |
| Drainage Area | 4 sq mi |
| Max Discharge | 160 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Fire Protection, Stock, Or Small Fish Pond |
| Owner | Decock Ranch Co |
| Owner Type | Private |
| Hazard Classification | Low |
| Condition Assessment | Not assessed |
| Emergency Action Plan | Not Required |
Identifiers
| NID ID | MT02098 |
| Federal ID | MT02098 |
| More Info | State Dam Safety Program |