Rock Lodge Pond Dam Reservoir Report

Last Updated: December 10, 2025

Rock Lodge Pond Dam, located in Hardyston, New Jersey, stands as a significant earth dam completed in 1907 to impound the waters of the Small Branch Pequannock River.


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Summary

With a height of 15 feet and a length of 300 feet, the dam has a storage capacity of 13 acre-feet and serves various purposes, including flood control and water supply. The dam is regulated and inspected by the New Jersey Department of Environmental Protection, ensuring its structural integrity and safety.

Despite its age, Rock Lodge Pond Dam remains in satisfactory condition, as indicated by the latest inspection in October 2021. The dam has a significant hazard potential, emphasizing the importance of regular maintenance and emergency preparedness. While there are no associated structures or locks, the dam plays a crucial role in managing water resources in the region and mitigating flood risks. Overall, Rock Lodge Pond Dam stands as a testament to early 20th-century engineering and continues to serve its purpose effectively in the present day.

For water resource and climate enthusiasts, Rock Lodge Pond Dam offers a fascinating glimpse into the history of dam construction and management in New Jersey. Its location in Sussex County, along with its association with the Small Branch Pequannock River, contributes to its significance in the local ecosystem. As efforts to address climate change intensify, the role of dams like Rock Lodge Pond Dam in water conservation and flood protection becomes increasingly vital. By understanding and appreciating the engineering marvel of Rock Lodge Pond Dam, enthusiasts can gain insights into the intersection of water resources, infrastructure, and environmental stewardship.

Year Completed

1907

Dam Length

300

Dam Height

15

River Or Stream

Small Branch Pequannock River

Primary Dam Type

Earth

Surface Area

3

Drainage Area

0.11

Nid Storage

13

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.