Mine Falls Reservoir Report

Last Updated: December 16, 2025

Mine Falls in Nashua, New Hampshire, is a historic masonry dam constructed in 1889 primarily for hydroelectric purposes.


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Summary

This dam on the Nashua River also serves for recreation and water supply, showcasing its versatility in meeting various community needs. With a height of 16 feet and a length of 325 feet, Mine Falls has a storage capacity of 1970 NID and a maximum discharge of 8981.

Managed by the NHDES Dam Bureau and regulated by the Federal Energy Regulatory Commission, Mine Falls has a low hazard potential and a moderate risk assessment. The dam features an uncontrolled spillway with a width of 132 feet and several outlet gates for controlled water release. While its condition assessment is not available, Mine Falls undergoes regular inspections and has an emergency action plan in place to ensure public safety in case of any unforeseen events.

Despite its age, Mine Falls continues to play a crucial role in the local landscape, offering both functional and recreational benefits to the community. As a key water resource infrastructure in the region, this historic dam stands as a testament to the harmonious integration of human development with natural resources, embodying the balance between water management and environmental stewardship in the face of evolving climate challenges.

Year Completed

1889

Dam Length

325

Dam Height

16

River Or Stream

Nashua River

Primary Dam Type

Masonry

Surface Area

242

Drainage Area

405

Nid Storage

1970

Outlet Gates

Other Controlled - 4, Slide (sluice gate) - 2

Hazard Potential

Low

Nid Height

16
       
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.