Ewans Mill Dam Reservoir Report

Last Updated: December 5, 2025

Ewans Mill Dam, located on the Mullica River in Gloucester, New Jersey, is a privately owned structure primarily used for recreational purposes.


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Summary

The dam, classified as an Earth type with a height of 15 feet and a length of 350 feet, provides a storage capacity of 31 acre-feet and covers a surface area of 22 acres. Despite its recreational value, the dam is facing significant hazard potential and has been assessed as being in poor condition as of March 2020.

The dam, regulated and inspected by the New Jersey Department of Environmental Protection, poses a risk due to its inadequate condition assessment and lack of emergency preparedness measures. Furthermore, with a drainage area of 5.8 square miles and a maximum discharge capacity of 70 cubic feet per second, the dam's structural integrity is crucial for managing water resources and protecting downstream areas from potential flooding. Efforts to address the dam's poor condition and enhance its safety measures are essential to ensure the long-term sustainability of the structure and the surrounding environment.

As climate change continues to impact water resources and extreme weather events become more frequent, the maintenance and management of dams like Ewans Mill Dam are crucial for mitigating risks and safeguarding communities. It is imperative for dam owners, regulators, and stakeholders to prioritize the rehabilitation and modernization of aging infrastructure to adapt to changing environmental conditions and ensure the resilience of water resource systems in the face of climate challenges.

Dam Length

350

Dam Height

15

River Or Stream

Mullica River

Primary Dam Type

Earth

Surface Area

22

Drainage Area

5.8

Nid Storage

31

Hazard Potential

Significant

Nid Height

15
       
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.