Mirror Lake Dam Reservoir Report
Nearby: Simonds Pond Dam Goodfellow Pond Dam
Last Updated: December 23, 2025
Mirror Lake Dam, located in Fitchburg, Massachusetts, is a local government-owned structure that serves the primary purpose of recreation.
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Summary
Completed in 1991, this earth dam with a buttress core stands at a height of 15 feet and has a normal storage capacity of 38 acre-feet. It is regulated by the Department of Conservation and Recreation and undergoes regular inspections to ensure its satisfactory condition and significant hazard potential.
Situated on the Monoosnoc Brook, a tributary to the Nashua River, Mirror Lake Dam provides a surface area of 7.5 acres and covers a drainage area of 0.13 square miles. With an uncontrolled spillway type, this dam has a maximum storage capacity of 45 acre-feet and a hydraulic height of 11.3 feet. Its risk assessment is moderate, with a risk management plan in place to mitigate potential hazards and ensure the safety of surrounding communities.
For water resource and climate enthusiasts, Mirror Lake Dam offers a fascinating insight into the intersection of human infrastructure and natural ecosystems. With its recreational purpose and regulatory framework, this dam serves as a crucial component of the local landscape, balancing the need for water storage with environmental considerations. As climate change continues to impact water resources, structures like Mirror Lake Dam play a vital role in managing and adapting to shifting conditions, highlighting the importance of sustainable water management practices for the future.
Year Completed |
1991 |
Dam Length |
150 |
Dam Height |
15 |
River Or Stream |
MONOOSNOC BROOK, TRIBUTARY TO NASHUA RIVER |
Primary Dam Type |
Earth |
Surface Area |
7.5 |
Hydraulic Height |
11.3 |
Drainage Area |
0.13 |
Nid Storage |
45 |
Hazard Potential |
Significant |
Foundations |
Unlisted/Unknown |
Nid Height |
15 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
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.
Mirror Lake Dam