Canobie Lake Dam Reservoir Report

Last Updated: December 16, 2025

Canobie Lake Dam, located in Salem, New Hampshire, serves as a vital recreational resource in the area.


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Summary

Completed in 1930, this earth dam stands at a height of 8 feet and spans 330 feet in length, creating a storage capacity of 1400 acre-feet with a normal storage level of 700 acre-feet. Situated on Policy Brook, the dam's primary purpose is for recreation, offering a surface area of 350 acres for various water activities.

Managed by the local government and regulated by the New Hampshire Department of Environmental Services Dam Bureau, Canobie Lake Dam has a low hazard potential and a moderate risk assessment rating. Despite its age, the dam has not been assessed for its condition and lacks an Emergency Action Plan (EAP) as of the latest inspection in November 2020. With a controlled spillway width of 4 feet and a maximum discharge capacity of 50 cubic feet per second, the dam presents a unique blend of historical significance and contemporary water management challenges.

As a significant feature in the Rockingham County landscape, Canobie Lake Dam provides not only recreational opportunities but also a critical water resource for the surrounding area. With its picturesque setting on Policy Brook and the potential for future risk management measures, the dam remains a focal point for water resource and climate enthusiasts seeking to understand the intersection of human infrastructure with natural hydrological systems.

Year Completed

1930

Dam Length

330

Dam Height

8

River Or Stream

POLICY BROOK

Primary Dam Type

Earth

Surface Area

350

Drainage Area

2.25

Nid Storage

1400

Hazard Potential

Low

Foundations

Unlisted/Unknown

Nid Height

8
       
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.