Long Dam
Long Dam is a gravity dam located in Carter County, Montana. It carries a Low hazard potential classification and has a fair condition assessment.
About Long Dam
The primary purpose of Long 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 Unnamed Drainage.
The dam stands 14 feet tall and stretches 4,026 feet across, creates a reservoir covering 32 acres, and has a maximum storage capacity of 60 acre-feet.
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 fair — the dam has minor deficiencies that are being addressed or do not pose an immediate safety threat. The most recent inspection on record was 09/05/2018.
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Location
| State | Montana |
| County | Carter |
| River/Stream | Unnamed Drainage |
| Coordinates | 45.66690, -104.52140 |
Physical Characteristics
| Dam Type | Gravity |
| NID Height | 14 ft |
| Dam Length | 4,026 ft |
Storage & Hydraulics
| NID Storage | 60 acre-ft |
| Max Storage | 60 acre-ft |
| Normal Storage | 28 acre-ft |
| Surface Area | 32 acres |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Flood Risk Reduction |
| Owner | DOI BLM |
| Owner Type | Federal |
| Hazard Classification | Low |
| Condition Assessment | Fair |
| Last Inspection | 09/05/2018 |
| Emergency Action Plan | Not Required |
Identifiers
| NID ID | MT00615 |
| Federal ID | MT00615 |
| More Info | State Dam Safety Program |