Hoague - Sprague Reservoir Report

Last Updated: December 16, 2025

Hoague - Sprague is a private hydroelectric dam located in Hopkinton, New Hampshire, along the Contoocook River.


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Summary

Built in 1906, this timber crib dam stands at a height of 14 feet and has a length of 350 feet, with a storage capacity of 26 acre-feet. The dam's primary purposes include hydroelectric power generation, fire protection, and maintaining a stock or small fish pond.

Managed by the New Hampshire Department of Environmental Services Dam Bureau, Hoague - Sprague is subject to state regulation, inspection, and enforcement. The dam is also federally regulated by the Federal Energy Regulatory Commission, which oversees its operations and inspections. With a spillway type of "Uncontrolled" and a significant hazard potential, the dam poses moderate risk, requiring risk management measures to ensure public safety and environmental protection.

Despite its age, Hoague - Sprague continues to play a vital role in water resource management and renewable energy production in the region. The dam's historical significance, combined with its modern regulatory oversight, highlights the importance of balancing water resource utilization with environmental protection in the face of evolving climate challenges.

Year Completed

1906

Dam Length

350

Dam Height

14

River Or Stream

Contoocook River

Primary Dam Type

Timber Crib

Surface Area

2

Drainage Area

427

Nid Storage

26

Outlet Gates

Slide (sluice gate) - 1

Hazard Potential

Significant

Nid Height

14
       
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.