Brainerd Lake Dam Reservoir Report

Last Updated: December 8, 2025

Brainerd Lake Dam, located in Plainsboro, New Jersey, is a significant earth dam completed in 1840 with a primary purpose of recreation.


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Summary

The dam stands at a height of 12.5 feet and has a storage capacity of 152 acre-feet, providing a serene surface area of 22 acres for visitors to enjoy. It is situated along Cranbury Brook and is regulated by the New Jersey Department of Environmental Protection (NJDEP), ensuring its safety and compliance with state regulations.

The dam's inspection in March 2020 deemed its condition as satisfactory, with a significant hazard potential due to its location and size. Despite this, the dam has met guidelines for emergency action plans, with a preparedness frequency of every two years. The surrounding area of Middlesex County, New Jersey, benefits from the recreational opportunities offered by Brainerd Lake Dam, creating a valuable asset for water resource and climate enthusiasts to appreciate and explore.

Overall, Brainerd Lake Dam serves as a vital structure for both leisure and environmental purposes in the region. Its historical significance, coupled with its role in providing recreation and regulating water resources, makes it a noteworthy site for those interested in the intersection of water management, infrastructure, and climate resilience.

Year Completed

1840

Dam Length

382

Dam Height

12.5

River Or Stream

Cranbury Brook

Primary Dam Type

Earth

Surface Area

22

Drainage Area

10.8

Nid Storage

152

Hazard Potential

Significant

Nid Height

13
       
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.