Souhegan Site 8 Dam Reservoir Report
Last Updated: December 17, 2025
Souhegan Site 8 Dam, also known as James A G Putnam Dam, is a crucial structure located in Lyndeborough, New Hampshire, along the Furnace Brook.
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Summary
Built in 1977 by the USDA NRCS, this earth dam stands at a height of 25 feet and spans 570 feet in length. Its primary purpose is flood risk reduction, with a storage capacity of 2,721 acre-feet and a maximum discharge rate of 7,030 cubic feet per second.
Managed by the New Hampshire Department of Environmental Services Dam Bureau, Souhegan Site 8 Dam is state-regulated and undergoes regular inspections to ensure its structural integrity. Classified as having a high hazard potential, the dam is currently in satisfactory condition and its risk assessment is rated as moderate. With its uncontrolled spillway and satisfactory emergency action plan, the dam serves as a vital infrastructure for water resource management in the region, highlighting the importance of proper maintenance and monitoring for climate resilience.
Despite its critical role in flood risk reduction, Souhegan Site 8 Dam faces potential risks that necessitate ongoing risk management measures. With its location in a high-hazard area and a moderate risk assessment, the dam serves as a focal point for water resource and climate enthusiasts interested in understanding the complexities of managing and maintaining essential infrastructure in the face of changing environmental conditions. As a key component of the water management system in Hillsborough County, New Hampshire, this dam symbolizes the delicate balance between human development and environmental stewardship in the context of climate change.
Year Completed |
1977 |
Dam Length |
570 |
Dam Height |
25 |
River Or Stream |
FURNACE BROOK |
Primary Dam Type |
Earth |
Surface Area |
40 |
Drainage Area |
4.7 |
Nid Storage |
2721 |
Hazard Potential |
High |
Foundations |
Unlisted/Unknown |
Nid Height |
25 |
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.
Souhegan Site 8 Dam
Zephyr Lake boat launch