Giles Pond Reservoir Report

Last Updated: December 18, 2025

Giles Pond, also known as Salmon Brook Station No.3 Dam, is a privately owned hydroelectric facility located in Franklin, New Hampshire.


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Summary

Built in 1904, this masonry dam stands at 18 feet high and spans 245 feet in length, with a maximum storage capacity of 860 acre-feet. It is regulated by the New Hampshire Department of Environmental Services Dam Bureau and the Federal Energy Regulatory Commission.

The dam's primary purpose is hydroelectric power generation, utilizing the flow of Salmon Brook to produce renewable energy. With a low hazard potential and a moderate risk assessment rating, Giles Pond is an important component of New Hampshire's water resource infrastructure. The dam has a spillway width of 49 feet and a maximum discharge capacity of 1800 cubic feet per second, serving as a crucial structure for managing water flow and storage in the region.

Despite its age, Giles Pond remains in good condition, with regular state inspections and a designated emergency action plan. It contributes to the local economy by providing clean, sustainable energy and supporting water supply management. As a key feature of the Salmon Brook watershed, this historic dam plays a vital role in the sustainable utilization of water resources and the mitigation of climate change impacts in the area.

Year Completed

1904

Dam Length

245

Dam Height

18

River Or Stream

Salmon Brook

Primary Dam Type

Masonry

Surface Area

43

Drainage Area

25

Nid Storage

860

Hazard Potential

Low

Nid Height

18
       
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.