Long Marsh Dam Reservoir Report
Last Updated: December 5, 2025
Long Marsh Dam, located in Genesee, New York, is a Federal-owned structure that serves multiple purposes.
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Summary
Completed in 1964, this earth-type dam stands at 11 feet tall and stretches 322 feet in length, with a storage capacity of 162 acre-feet. Situated on the TR-Oak Orchard Creek, Long Marsh Dam is regulated by the New York State Department of Environmental Conservation and is subject to regular inspections, permitting, and enforcement to ensure its safety and compliance with state regulations.
With a low hazard potential and a moderate risk assessment rating, Long Marsh Dam poses minimal danger to surrounding areas. Despite its age and lack of recent condition assessments, the dam remains in a satisfactory state and has not been rated for its current condition. The spillway, an uncontrolled type with a width of 20 feet, allows for a maximum discharge of 328 cubic feet per second. While there are no associated structures or locks, the dam provides vital water resource management for the region and plays a crucial role in flood control and water storage for the Oak Orchard Creek watershed.
Overall, Long Marsh Dam serves as a key infrastructure asset in the Buffalo District, managed by the US Army Corps of Engineers. Its strategic location and design contribute to the mitigation of flood risks and the maintenance of water resources in the area. As a Federal-owned structure, Long Marsh Dam highlights the importance of effective management and regulation of water resources to ensure the safety and sustainability of our environment in the face of climate change challenges.
Year Completed |
1964 |
Dam Length |
322 |
Dam Height |
11 |
River Or Stream |
TR-OAK ORCHARD CREEK |
Primary Dam Type |
Earth |
Surface Area |
65 |
Drainage Area |
0.63 |
Nid Storage |
162 |
Hazard Potential |
Low |
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.
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