Mercer Bog Reservoir Report
Nearby: Coffin Clearwater Pond
Last Updated: December 18, 2025
Mercer Bog in Somerset, Maine, is a state-regulated water resource managed by the Maine Emergency Management Agency (MEMA).
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Summary
This recreational pond, fed by Bog Stream, features a concrete dam with a height of 27 feet and a hydraulic height of 24 feet. Completed in 1850, the dam has a storage capacity of 951 acre-feet and covers a surface area of 317 acres. Despite its age, Mercer Bog has a low hazard potential and is currently classified as "Not Rated" in terms of condition assessment.
The dam at Mercer Bog serves multiple purposes, including fish and wildlife habitat enhancement and recreational activities. The structure, with a length of 132 feet and a spillway width of 34 feet, has not undergone significant modifications in recent years. Emergency preparedness measures, such as an Emergency Action Plan (EAP) and inundation maps, are not currently in place for this site. Despite this, the dam is subject to regular inspections with a frequency of 12 months to ensure its safety and integrity for both the surrounding community and the environment.
Water enthusiasts and climate advocates can appreciate Mercer Bog for its role in providing a habitat for local wildlife and offering recreational opportunities for residents and visitors. With its historical significance dating back to the 19th century, this water resource showcases the balance between human enjoyment and environmental stewardship. Continued monitoring and maintenance efforts will be crucial to preserve the functionality and safety of the dam at Mercer Bog for future generations to enjoy.
Year Completed |
1850 |
Dam Length |
132 |
Dam Height |
27 |
River Or Stream |
Bog Stream |
Primary Dam Type |
Concrete |
Surface Area |
317 |
Hydraulic Height |
24 |
Nid Storage |
951 |
Structural Height |
27 |
Hazard Potential |
Low |
Nid Height |
27 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Sandy River Near Mercer
|
326cfs |
Carrabassett River Near North Anson
|
304cfs |
Kennebec River At North Sidney
|
2360cfs |
Kennebec River At Bingham
|
1990cfs |
Austin Stream At Bingham
|
55cfs |
Androscoggin River At Rumford
|
3360cfs |
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.
Mercer Bog
North Shore Drive Smithfield