Whittemore Lake Dam Reservoir Report
Nearby: Powder Mill Monadnock
Last Updated: December 19, 2025
Whittemore Lake Dam, located in Bennington, New Hampshire, on the TR Contoocook River, was completed in 1886 for the primary purpose of recreation.
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Summary
This State-owned dam stands at 11 feet high with a length of 120 feet, providing a storage capacity of 213 acre-feet and covering a surface area of 40.5 acres. Despite its low hazard potential, the dam's condition assessment is currently rated as poor, indicating a need for maintenance and repairs to ensure the structure's continued safety and functionality.
Managed by the NHDES Dam Bureau, Whittemore Lake Dam is subject to state regulations, permitting, inspection, and enforcement. With a moderate risk assessment and a history of poor condition, there is a pressing need for improved risk management measures to address potential safety concerns. The dam's spillway type is uncontrolled with a width of 40 feet, capable of discharging up to 639 cubic feet per second. As a popular recreation spot, the dam plays a vital role in providing outdoor activities for residents and visitors in the Hillsborough County area.
For water resource and climate enthusiasts, the Whittemore Lake Dam presents an intriguing case study of a historic earth dam that requires attention to maintain its structural integrity and ensure public safety. With its location on the Contoocook River, the dam's impact on local hydrology and ecology underscores the importance of responsible dam management practices. As discussions continue regarding the dam's future maintenance and risk mitigation strategies, stakeholders must prioritize sustainable solutions to preserve this valuable resource for future generations.
Year Completed |
1886 |
Dam Length |
120 |
Dam Height |
11 |
River Or Stream |
TR CONTOOCOOK RIVER |
Primary Dam Type |
Earth |
Surface Area |
40.5 |
Drainage Area |
2 |
Nid Storage |
213 |
Hazard Potential |
Low |
Foundations |
Unlisted/Unknown |
Nid Height |
11 |
Seasonal Comparison
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Nearby Streamflow Levels
Dam Data Reference
Condition Assessment
SatisfactoryNo 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
HighDams 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.
Whittemore Lake Dam
Contoocook River (Powder Mill Pond) boat launch