Diamond Lake Dam Reservoir Report

Last Updated: December 5, 2025

Diamond Lake Dam, located in Gloucester, New Jersey, is a privately owned structure regulated by the New Jersey Department of Environmental Protection.


°F

°F

mph

Wind

%

Humidity

Summary

The dam, built for recreational purposes, stands at a height of 10.5 feet and has a storage capacity of 100 acre-feet. The dam spans a length of 600 feet and impounds the waters of Hospitality Branch.

Despite being classified as having a low hazard potential and fair condition assessment, Diamond Lake Dam undergoes regular inspections every four years to ensure its safety and structural integrity. The last inspection was conducted in September 2011. The dam does not have a designated spillway type or maximum discharge rate, indicating a need for further risk assessment and management measures to be implemented in the future.

Overall, Diamond Lake Dam serves as a vital recreational resource in Monroe Township, providing opportunities for water-based activities and enjoyment for residents and visitors alike. As climate change continues to impact water resources, it is essential for dam owners and regulatory agencies to prioritize the maintenance and safety of structures like Diamond Lake Dam to mitigate potential risks and ensure the long-term sustainability of water systems in the region.

Dam Length

600

Dam Height

10.5

River Or Stream

Hospitality Branch

Primary Dam Type

Earth

Surface Area

18

Drainage Area

19.3

Nid Storage

100

Hazard Potential

Low

Nid Height

11
       
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.