Great Moose Lake
Great Moose Lake is a concrete dam located in Somerset County, Maine, built in 1924. It carries a Significant hazard potential classification and has a satisfactory condition assessment.
About Great Moose Lake
The primary purpose of Great Moose Lake 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 Hartland (local government). It impounds the Sebasticook River.
The dam stands 16 feet tall and stretches 350 feet across, creates a reservoir covering 3,584 acres, has a maximum storage capacity of 26,880 acre-feet, and collects water from a drainage area of 228 square miles. Completed in 1924, the structure is over a century old.
This dam has a significant hazard potential classification, meaning that a failure could cause significant economic damage — flooding roads, bridges, or property downstream — but is not expected to result in loss of life. Its condition is rated satisfactory, indicating no existing or potential dam safety deficiencies are recognized. An emergency action plan is in place for this dam. The most recent inspection on record was 05/30/2024.
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Location
| State | Maine |
| County | Somerset |
| River/Stream | Sebasticook River |
| Coordinates | 44.88489, -69.45370 |
Physical Characteristics
| Dam Type | Concrete |
| NID Height | 16 ft |
| Dam Height | 16 ft |
| Dam Length | 350 ft |
| Year Completed | 1924 (102 years old) |
Storage & Hydraulics
| NID Storage | 26,880 acre-ft |
| Max Storage | 26,880 acre-ft |
| Normal Storage | 23,520 acre-ft |
| Surface Area | 3,584 acres |
| Drainage Area | 228 sq mi |
Ownership & Safety
| Purpose | Flood Risk Reduction |
| Owner | Hartland |
| Owner Type | Local Government |
| Hazard Classification | Significant |
| Condition Assessment | Satisfactory |
| Last Inspection | 05/30/2024 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | ME00112 |
| Federal ID | ME00112 |
| More Info | State Dam Safety Program |