Lake Marie Dam Reservoir Report
Nearby: Frog Pond Dam Robinson Pond Dam
Last Updated: December 25, 2025
Lake Marie Dam, located in Windham, Connecticut, stands as a crucial water resource with a primary purpose of recreation.
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Summary
This private dam, completed in 1880, spans 160 feet in length and reaches a height of 8.5 feet, providing a storage capacity of 73 acre-feet and covering a surface area of 20 acres. The dam overlooks the picturesque Ballymahack Brook, enhancing the natural beauty of the surrounding landscape while serving as a recreational haven for water and climate enthusiasts alike.
Maintained by the state-regulated Department of Energy and Environmental Protection (DEEP), Lake Marie Dam boasts a significant hazard potential, yet its condition is assessed as satisfactory. Regular inspections are conducted every 7 years to ensure the dam's structural integrity and safety for the community. With a maximum discharge capacity of 31 cubic feet per second, the dam is equipped to manage water levels effectively, showcasing both its functional value and environmental importance in the region's water management system.
While the dam's Emergency Action Plan (EAP) status and risk management measures remain undisclosed, Lake Marie Dam's historical significance and enduring role in providing recreational opportunities and water resource management underscore its vital importance in the community. As a focal point for outdoor activities and a critical piece in the local water infrastructure, Lake Marie Dam stands as a testament to the intersection of human innovation and environmental stewardship in safeguarding our natural resources for future generations.
Year Completed |
1880 |
Dam Length |
160 |
Dam Height |
8.5 |
River Or Stream |
BALLYMAHACK BROOK |
Primary Dam Type |
Earth |
Surface Area |
20 |
Drainage Area |
1.87 |
Nid Storage |
73 |
Hazard Potential |
Significant |
Nid Height |
9 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Shetucket River Near Willimantic
|
702cfs |
Natchaug River At Willimantic
|
320cfs |
Little River Near Hanover
|
44cfs |
Willimantic River Near Coventry
|
161cfs |
Mount Hope River Near Warrenville
|
38cfs |
Yantic River At Yantic
|
105cfs |
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.
Lake Marie Dam
Beaver Brook Pond