Farrar Marsh Dam Reservoir Report
Last Updated: December 19, 2025
Farrar Marsh Dam, located in Hillsborough, New Hampshire, stands as a vital recreational resource for the community since its completion in 1978.
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Summary
This earth dam on Sand Brook boasts a height of 10.5 feet, with a storage capacity of 654 acre-feet and a surface area of 140 acres. Despite being primarily used for recreation purposes, the dam also serves as a crucial water resource, with a drainage area of 5.8 square miles and a maximum discharge capability of 1565 cubic feet per second.
Managed by the New Hampshire Department of Environmental Services Dam Bureau, Farrar Marsh Dam is regulated, inspected, and enforced by the state, ensuring its safety and compliance with environmental standards. The dam's condition assessment is rated as fair, with a significant hazard potential and moderate risk level. With its uncontrolled spillway and a spillway width of 72 feet, the dam is equipped to handle emergencies effectively. The surrounding area, under the jurisdiction of the state, benefits from the dam's presence, providing both recreational and ecological advantages to the region.
As climate change continues to impact water resources and ecosystems, the management and maintenance of dams like Farrar Marsh Dam become increasingly crucial. With its strategic location on Sand Brook and its role in water storage and recreation, this dam exemplifies the intersection between human infrastructure and natural landscapes. By adhering to state regulations, conducting regular inspections, and implementing risk management measures, Farrar Marsh Dam stands as a resilient structure in the face of evolving environmental challenges, safeguarding the community's water resources and enhancing the local ecosystem for generations to come.
Year Completed |
1978 |
Dam Length |
110 |
Dam Height |
10.5 |
River Or Stream |
SAND BROOK |
Primary Dam Type |
Earth |
Surface Area |
140 |
Drainage Area |
5.8 |
Nid Storage |
654 |
Hazard Potential |
Significant |
Foundations |
Unlisted/Unknown |
Nid Height |
11 |
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.
Farrar Marsh Dam
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