Seneca Lake Dam Reservoir Report

Last Updated: December 9, 2025

Seneca Lake Dam, located in Sparta Township, New Jersey, is a privately owned structure designed for recreational purposes.


°F

°F

mph

Wind

%

Humidity

Summary

The dam is situated on Lubbers Run and is regulated by the New Jersey Department of Environmental Protection. With a height of 11 feet and a length of 200 feet, the dam has a storage capacity of 60 acre-feet and covers a surface area of 23 acres. Despite its significant hazard potential, the dam's condition was assessed as satisfactory during the last inspection in October 2020.

The dam's primary purpose is to provide recreational opportunities, attracting water resource and climate enthusiasts to enjoy the scenic surroundings of Seneca Lake. Although no major modifications or risk management measures have been reported, the dam's emergency action plan was last revised in January 2021. With a designated inspection frequency of every two years, the dam's maintenance and safety protocols are regularly monitored to ensure the protection of downstream communities in Sussex County, New Jersey.

Seneca Lake Dam, part of the Philadelphia District of the US Army Corps of Engineers, serves as a vital water resource for the region. As a gravity earth dam, it plays a crucial role in managing water flow and storage for the surrounding area. While the dam's spillway type and width are unspecified, its satisfactory condition assessment and regular inspections indicate a commitment to maintaining the dam's integrity and safety for both recreational users and the local ecosystem.

Dam Length

200

Dam Height

11

River Or Stream

Lubbers Run

Primary Dam Type

Earth

Surface Area

23

Drainage Area

1.8

Nid Storage

60

Hazard Potential

Significant

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.
View more

Area Campgrounds