Howe Reservoir Dam Reservoir Report

Last Updated: December 18, 2025

Howe Reservoir Dam in Harrisville, New Hampshire, stands as a testament to the state's commitment to recreation and water resource management.


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Summary

Completed in 1924, this earth dam spans 157 feet in length and reaches a height of 28 feet, providing storage of up to 2086 acre-feet. The reservoir itself covers 208 acres and is fed by the serene TR Minnewawa Brook, offering a picturesque setting for outdoor enthusiasts.

Despite its significant contributions to water storage and recreational activities, Howe Reservoir Dam faces challenges in terms of its maintenance and condition. With a hazard potential rated as high and a poor condition assessment, the dam requires regular inspections and enforcement by the NHDES DAM BUREAU to ensure public safety. The risk assessment for the dam is moderate, indicating the need for ongoing risk management measures to mitigate potential hazards and safeguard the surrounding communities.

As climate change continues to impact water resources and infrastructure, Howe Reservoir Dam serves as a vital reminder of the importance of proactive management and investment in maintaining the integrity of our dams. With its historical significance and recreational value, this dam stands as a symbol of New Hampshire's commitment to balancing water resource utilization with environmental preservation in the face of evolving climate conditions.

Year Completed

1924

Dam Length

157

Dam Height

28

River Or Stream

TR MINNEWAWA BROOK

Primary Dam Type

Earth

Surface Area

208

Drainage Area

10.6

Nid Storage

2086

Hazard Potential

High

Foundations

Unlisted/Unknown

Nid Height

28
       
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.