Upper Massapequa Lake Dam Reservoir Report
Nearby: Massapequa Lake Dam Belmont Lake Dam
Last Updated: January 2, 2026
Upper Massapequa Lake Dam, located in Massapequa, New York, is a significant earth dam completed in 1900 primarily for recreational purposes, offering a serene escape for water resource and climate enthusiasts.
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Summary
With a height of 11 feet and a length of 200 feet, this dam provides a storage capacity of 128 acre-feet and covers a surface area of 17 acres. It is regulated by the New York State Department of Environmental Conservation, ensuring proper inspection, permitting, and enforcement to maintain its structural integrity.
Despite its historical significance, the dam's condition has been assessed as poor, with a significant hazard potential due to its outdated design and maintenance issues. The last inspection in November 2018 highlighted the need for immediate attention to address safety concerns and mitigate risks. The emergency action plan is yet to be prepared or updated, indicating a gap in preparedness for potential incidents. With a moderate risk assessment rating of 3, it is crucial for stakeholders to prioritize the dam's rehabilitation and risk management measures to ensure the safety of the surrounding community and environment.
In light of the dam's condition and associated risks, collaboration between local government authorities, regulatory agencies, and stakeholders is essential to develop a comprehensive plan for the dam's rehabilitation and maintenance. By addressing the structural deficiencies, updating emergency protocols, and implementing risk management strategies, Upper Massapequa Lake Dam can continue to provide recreational opportunities while safeguarding the community and ecosystem from potential hazards. Water resource and climate enthusiasts are encouraged to advocate for responsible stewardship of this vital infrastructure to preserve its value for future generations.
Year Completed |
1900 |
Dam Length |
200 |
Dam Height |
11 |
River Or Stream |
MASSAPEQUA BROOK |
Primary Dam Type |
Earth |
Surface Area |
17 |
Drainage Area |
38.5 |
Nid Storage |
128 |
Hazard Potential |
Significant |
Nid Height |
11 |
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.
Upper Massapequa Lake Dam
Milburn Creek Boat Launch