Kimball Lake Dam Reservoir Report

Last Updated: December 15, 2025

Kimball Lake Dam, also known as Dolf Brook Dam, is a local government-owned structure in Hopkinton, New Hampshire.


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Summary

Completed in 1930, this earth dam stands at a height of 7 feet and has a length of 110 feet, with a primary purpose of recreation. The dam boasts a storage capacity of 292 acre-feet and serves the Kimball Lake river or stream, providing a surface area of 27 acres for recreational activities.

Despite its low hazard potential, Kimball Lake Dam is in poor condition as of the last assessment in November 2017. The dam is regulated by the NHDES Dam Bureau, which ensures that inspections, permitting, and enforcement are carried out to meet state standards. The structure has an uncontrolled spillway with a width of 10 feet and a maximum discharge capacity of 583 cubic feet per second, making it a critical part of the local water resource infrastructure.

As a significant feature in the Merrimack County landscape, Kimball Lake Dam presents both opportunities for recreation and challenges for maintenance and risk management. Climate and water resource enthusiasts can appreciate the historical significance and ecological impact of this dam while also recognizing the importance of ongoing inspections and maintenance to ensure its safety and functionality for future generations.

Year Completed

1930

Dam Length

110

Dam Height

7

River Or Stream

KIMBALL LAKE

Primary Dam Type

Earth

Surface Area

27

Drainage Area

1.1

Nid Storage

292

Hazard Potential

Low

Foundations

Unlisted/Unknown

Nid Height

7
       
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.