Webster Reservoir Report

Last Updated: December 18, 2025

Webster is a captivating hydroelectric dam located on the Suncook River in Pembroke, New Hampshire.


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Summary

Owned privately, this concrete gravity dam stands at 22 feet high and stretches 250 feet in length, with a storage capacity of 147 acre-feet. Completed in 1917, Webster serves as a dual-purpose structure for hydroelectric power generation and recreational activities in the area.

Managed by the New Hampshire Department of Environmental Services Dam Bureau and regulated by the Federal Energy Regulatory Commission, Webster's operational safety is ensured through regular inspections and enforcement measures. With a significant hazard potential due to its location and design, the dam is subject to a moderate risk assessment. Emergency action plans are in place, meeting guidelines for potential risks and ensuring the safety of surrounding communities in case of any unforeseen events.

The dam's historical significance, coupled with its vital role in providing renewable energy and recreational opportunities, highlights Webster as a crucial water resource structure in the region. As a focal point for water resource and climate enthusiasts, Webster stands as a testament to sustainable energy practices and responsible dam management in New Hampshire's Merrimack County.

Year Completed

1917

Dam Length

250

Dam Height

22

River Or Stream

Suncook River

Primary Dam Type

Concrete

Surface Area

15

Drainage Area

259

Nid Storage

147

Outlet Gates

Other Controlled - 1

Hazard Potential

Significant

Nid Height

22
       
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.