Wallkill Lake Dam Reservoir Report

Last Updated: December 11, 2025

Located in Vernon Township, New Jersey, the Wallkill Lake Dam is a privately owned structure regulating the Wallkill River-TR.


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Summary

Built in 1930, this earth dam stands at 15 feet high and spans 490 feet in length, with a storage capacity of 215 acre-feet. The dam primarily serves recreational purposes, offering a surface area of 26 acres for visitors to enjoy various water activities. Despite being state-regulated by the NJDEP and regularly inspected, the dam is classified as having low hazard potential and is in fair condition as of the last assessment in 2018.

With a maximum discharge of 900 cubic feet per second, the Wallkill Lake Dam plays a crucial role in managing the drainage area of 0.8 square miles. The dam's primary purpose is to provide recreational opportunities for the community while ensuring the safety and integrity of the surrounding environment. Although there have been no major modifications or incidents reported at the dam, emergency preparedness measures such as an Emergency Action Plan (EAP) are yet to be established, highlighting the importance of proactive risk management strategies in safeguarding this vital water resource.

As a key component of the local landscape, the Wallkill Lake Dam not only offers recreational amenities but also serves as a critical infrastructure for flood control and water resource management in Sussex County, New Jersey. With its historical significance dating back to the early 20th century, this earth dam stands as a testament to human ingenuity and engineering prowess in harnessing the power of water for the benefit of the community. As climate change continues to pose challenges to water resources, the Wallkill Lake Dam remains an essential asset in ensuring the sustainable use and conservation of this precious natural resource for future generations.

Year Completed

1930

Dam Length

490

Dam Height

15

River Or Stream

Wallkill River-TR

Primary Dam Type

Earth

Surface Area

26

Drainage Area

0.8

Nid Storage

215

Hazard Potential

Low

Nid Height

15
       
Seasonal Comparison

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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.