Fawn Lake Dam Reservoir Report

Last Updated: December 11, 2025

Fawn Lake Dam, located in Hardyston, New Jersey, is a privately owned structure that serves primarily for recreational purposes.


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Summary

Built in 1940, this earthen dam stands at a height of 22 feet and has a length of 600 feet, creating a reservoir with a storage capacity of 23 acre-feet. The dam is situated on the Wallkill River-TR and is regulated by the New Jersey Department of Environmental Protection (NJDEP).

Despite its recreational significance, Fawn Lake Dam poses a significant hazard potential and has been assessed as being in poor condition as of August 2020. With a drainage area of 0.11 square miles and a maximum discharge capacity of 45 cubic feet per second, the dam requires frequent inspections, which are conducted every two years. The emergency action plan for the dam was last revised in November 2020, indicating the ongoing efforts to ensure the safety and integrity of the structure.

As a critical component of water resource management in Sussex County, New Jersey, Fawn Lake Dam serves as a reminder of the importance of maintaining and monitoring infrastructure for both recreational and safety purposes. With its historical significance and environmental impact on the surrounding area, the dam requires continual attention to mitigate potential risks and ensure the well-being of the community and ecosystem.

Year Completed

1940

Dam Length

600

Dam Height

22

River Or Stream

Wallkill River-TR

Primary Dam Type

Earth

Surface Area

8

Drainage Area

0.11

Nid Storage

23

Hazard Potential

Significant

Nid Height

22
       
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.