Sunset Lake Dam Reservoir Report

Last Updated: December 6, 2025

Sunset Lake Dam, located in Hurleyville, New York, is a local government-owned structure on the East Mongaup River.


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Summary

The dam serves as a recreational site and has a primary purpose of providing opportunities for outdoor activities. Standing at a height of 18 feet with a length of 246 feet, the dam can store up to 128 acre-feet of water, with a normal storage capacity of 51 acre-feet. Despite being classified as having a low hazard potential, the dam's risk assessment indicates a high risk level, prompting the need for careful monitoring and management.

Managed by the New York State Department of Environmental Conservation (NYS DEC), Sunset Lake Dam is subject to state regulation, permitting, inspection, and enforcement. The dam does not have a spillway, but it does have a spillway width of 20 feet, contributing to its overall safety measures. Although the last inspection was conducted in 2009 and the condition assessment is currently marked as "Not Rated," the dam's risk management measures are essential in ensuring the safety of surrounding areas and preventing potential hazards. With a risk level of 2, it emphasizes the importance of continued monitoring and assessment to mitigate any potential threats.

As a key feature in the Sullivan County landscape, Sunset Lake Dam provides both recreational opportunities and water resource management for the local community. With its strategic location and significant storage capacity, the dam serves as a valuable asset for both environmental enthusiasts and climate-conscious individuals. By adhering to state regulations and implementing risk management measures, Sunset Lake Dam plays a crucial role in maintaining water resources and ensuring the safety of its surroundings in Hurleyville, New York.

Dam Length

246

Dam Height

18

River Or Stream

EAST MONGAUP RIVER

Primary Dam Type

Earth

Surface Area

13

Drainage Area

0.24

Nid Storage

128

Hazard Potential

Low

Nid Height

18
       
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.