Exeter River Dam Reservoir Report
Last Updated: December 15, 2025
The Exeter River Dam, also known as the Mill Road Dam, is a private-owned structure located in Brentwood, New Hampshire.
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Summary
Built in 1927, this concrete dam stands at a height of 15 feet and spans 130 feet across the Exeter River. Its primary purpose is for recreation, offering a surface area of 16.4 acres and a normal storage capacity of 72 acre-feet. The dam is regulated by the NHDES Dam Bureau and undergoes regular inspections to ensure safety and compliance with state regulations.
Despite its recreational value, the Exeter River Dam poses a significant hazard potential with a poor condition assessment as of the last inspection in June 2017. The dam's risk assessment is rated as moderate, indicating the need for risk management measures to address any potential issues that may arise. With a drainage area of 60.65 square miles, the dam plays a crucial role in water resource management and flood control along the Exeter River. Enthusiasts of water resources and climate will find the Exeter River Dam an intriguing structure to study and monitor for its impact on the surrounding environment.
Year Completed |
1927 |
Dam Length |
130 |
Dam Height |
15 |
River Or Stream |
EXETER RIVER |
Primary Dam Type |
Concrete |
Surface Area |
16.4 |
Drainage Area |
60.65 |
Nid Storage |
296 |
Hazard Potential |
Significant |
Foundations |
Unlisted/Unknown |
Nid Height |
15 |
Seasonal Comparison
Weather Forecast
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.
Exeter River Dam
Greenwood Pond boat launch