Summit Lake Dam Reservoir Report

Last Updated: December 10, 2025

Summit Lake Dam, located in Stockholm, New Jersey, is a privately owned earth dam that serves primarily for recreational purposes.


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Summary

The dam, standing at a height of 5 feet and with a length of 250 feet, impounds the waters of the Wallkill River, providing a maximum storage capacity of 37 acre-feet and a normal storage of 22 acre-feet. The dam has a surface area of 11 acres and drains an area of 0.04 square miles.

Managed by the New Jersey Department of Environmental Protection, Summit Lake Dam is classified as a significant hazard potential structure with a satisfactory condition assessment as of the last inspection in July 2020. The dam does not have an emergency action plan in place and has not been modified in recent years. With a maximum discharge capacity of 101 cubic feet per second, the dam plays a crucial role in flood control and water resource management in the region.

Despite its relatively small size, Summit Lake Dam is a vital part of the water infrastructure in Sussex County, New Jersey. The dam's presence not only supports recreational activities but also contributes to the overall ecological health of the Wallkill River watershed. As climate change continues to impact water resources, the proper maintenance and regulation of dams like Summit Lake Dam will be crucial in ensuring the safety and sustainability of water supplies for both human and environmental needs.

Dam Length

250

Dam Height

5

River Or Stream

Wallkill River

Primary Dam Type

Earth

Surface Area

11

Drainage Area

0.04

Nid Storage

37

Hazard Potential

Significant

Nid Height

5
       
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.