Knowlesville Marsh Dam Reservoir Report

Last Updated: December 5, 2025

Knowlesville Marsh Dam, located in Genesee, New York, is a Federal-owned structure managed by the U.S.


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Summary

Fish & Wildlife Service. Built in 1964, this Earth-type dam serves as a vital component of the area's Fish and Wildlife Pond, with a primary purpose of providing habitat for various species. The dam stands at 11 feet tall and spans a length of 940 feet, with a capacity to store 274 acre-feet of water for the conservation of the surrounding environment.

Managed and regulated by the New York State Department of Environmental Conservation, Knowlesville Marsh Dam has a controlled spillway to manage water flow, ensuring the safety and stability of the structure. Despite its fair condition assessment as of July 2019, the dam is classified as having low hazard potential with a very high risk assessment rating. Regular inspections are conducted every five years to monitor its structural integrity and ensure compliance with safety standards, emphasizing the importance of maintaining this critical water resource infrastructure.

As a key feature of the tributary to Oak Orchard Creek, Knowlesville Marsh Dam plays a crucial role in supporting the biodiversity and ecological health of the region. With its strategic design and management by the U.S. Fish & Wildlife Service, this dam stands as a testament to the collaborative efforts between federal and state agencies in promoting sustainable water resource management in New York.

Year Completed

1964

Dam Length

940

Dam Height

11

River Or Stream

Tributary to Oak Orchard Creek

Primary Dam Type

Earth

Surface Area

6.1

Hydraulic Height

11

Drainage Area

0.53

Nid Storage

274

Structural Height

11

Outlet Gates

Other Controlled

Hazard Potential

Low

Foundations

Soil

Nid Height

11
       
Seasonal Comparison

Weather Forecast

Dam Data Reference

Condition Assessment

Satisfactory
No 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

High
Dams 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.