Great Moose Lake Reservoir Report
Nearby: Indian Pond Mulligan Bog
Last Updated: December 19, 2025
Great Moose Lake, located in Somerset County, Maine, is a picturesque body of water that serves multiple purposes, including flood risk reduction, fire protection, and recreation.
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Summary
The dam at Great Moose Lake, completed in 1924, is primarily made of concrete and stands at a height of 15.5 feet, with a hydraulic height of 10 feet. The lake has a storage capacity of 26,880 acre-feet, with a normal storage level of 23,520 acre-feet. The dam's condition was last assessed as satisfactory in November 2019, with a significant hazard potential.
Managed by the Maine Emergency Management Agency (MEMA), Great Moose Lake is regulated and permitted by the state, ensuring its safety and compliance with environmental regulations. The lake's drainage area covers 228 square miles, with a surface area of 3,584 acres. Its proximity to the Sebasticook River adds to its ecological significance, providing a vital habitat for fish and wildlife. With its stunning natural beauty and essential role in flood mitigation efforts, Great Moose Lake is a valuable resource for both the local community and the environment.
For water resource and climate enthusiasts, Great Moose Lake offers a fascinating case study in dam management and the intersection of human infrastructure with natural ecosystems. Its rich history, diverse purposes, and ongoing maintenance highlight the importance of sustainable water management practices in the face of changing climate conditions. As a key player in flood risk reduction and environmental conservation, Great Moose Lake stands as a testament to the crucial role that water resources play in shaping resilient and vibrant communities.
Year Completed |
1924 |
Dam Length |
350 |
Dam Height |
15.5 |
River Or Stream |
Sebasticook River |
Primary Dam Type |
Concrete |
Surface Area |
3584 |
Hydraulic Height |
10 |
Drainage Area |
228 |
Nid Storage |
26880 |
Structural Height |
15.5 |
Hazard Potential |
Significant |
Nid Height |
16 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Kingsbury Stream At Abbot Village
|
60cfs |
Piscataquis River Near Dover-Foxcroft
|
341cfs |
Kennebec River At Bingham
|
2680cfs |
Austin Stream At Bingham
|
55cfs |
Carrabassett River Near North Anson
|
304cfs |
Sandy River Near Mercer
|
326cfs |
Dam Data Reference
Condition Assessment
SatisfactoryNo existing or potential dam safety deficiencies are recognized. Acceptable performance is expected under all loading conditions (static, hydrologic, seismic) in accordance with the minimum applicable state or federal regulatory criteria or tolerable risk guidelines.
Fair
No existing dam safety deficiencies are recognized for normal operating conditions. Rare or extreme hydrologic and/or seismic events may result in a dam safety deficiency. Risk may be in the range to take further action. Note: Rare or extreme event is defined by the regulatory agency based on their minimum
Poor A dam safety deficiency is recognized for normal operating conditions which may realistically occur. Remedial action is necessary. POOR may also be used when uncertainties exist as to critical analysis parameters which identify a potential dam safety deficiency. Investigations and studies are necessary.
Unsatisfactory
A dam safety deficiency is recognized that requires immediate or emergency remedial action for problem resolution.
Not Rated
The dam has not been inspected, is not under state or federal jurisdiction, or has been inspected but, for whatever reason, has not been rated.
Not Available
Dams for which the condition assessment is restricted to approved government users.
Hazard Potential Classification
HighDams assigned the high hazard potential classification are those where failure or mis-operation will probably cause loss of human life.
Significant
Dams assigned the significant hazard potential classification are those dams where failure or mis-operation results in no probable loss of human life but can cause economic loss, environment damage, disruption of lifeline facilities, or impact other concerns. Significant hazard potential classification dams are often located in predominantly rural or agricultural areas but could be in areas with population and significant infrastructure.
Low
Dams assigned the low hazard potential classification are those where failure or mis-operation results in no probable loss of human life and low economic and/or environmental losses. Losses are principally limited to the owner's property.
Undetermined
Dams for which a downstream hazard potential has not been designated or is not provided.
Not Available
Dams for which the downstream hazard potential is restricted to approved government users.
Great Moose Lake