Jim Detention Dam
Jim Detention Dam is a gravity dam located in Valley County, Montana, built in 1964. It carries a Low hazard potential classification and has a satisfactory condition assessment.
About Jim Detention Dam
The primary purpose of Jim Detention Dam is flood risk reduction. The dam is designed to control downstream flooding by temporarily storing excess water during storms and releasing it at a controlled rate. The dam is owned by Doi Blm (federal). It impounds the Willow Ck./milk River near Nashua.
The dam stands 19 feet tall and stretches 1,150 feet across, creates a reservoir covering 163 acres, has a maximum storage capacity of 1,320 acre-feet, and collects water from a drainage area of 25 square miles. Completed in 1964, 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. Its condition is rated satisfactory, indicating no existing or potential dam safety deficiencies are recognized. The most recent inspection on record was 10/24/2017.
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Location
| State | Montana |
| County | Valley |
| Nearest City | Nashua |
| River/Stream | Willow Ck./milk River |
| Coordinates | 48.02709, -107.06314 |
Physical Characteristics
| Dam Type | Gravity |
| NID Height | 19 ft |
| Dam Length | 1,150 ft |
| Year Completed | 1964 (62 years old) |
Storage & Hydraulics
| NID Storage | 1,380 acre-ft |
| Max Storage | 1,320 acre-ft |
| Normal Storage | 1,380 acre-ft |
| Surface Area | 163 acres |
| Drainage Area | 25 sq mi |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Flood Risk Reduction |
| Owner | DOI BLM |
| Owner Type | Federal |
| Hazard Classification | Low |
| Condition Assessment | Satisfactory |
| Last Inspection | 10/24/2017 |
| Emergency Action Plan | Not Required |
Identifiers
| NID ID | MT00735 |
| Federal ID | MT00735 |
| More Info | State Dam Safety Program |