Souhegan Site 8 South Dike Reservoir Report
Last Updated: December 17, 2025
Souhegan Site 8 South Dike, also known as the James A G Putnam Dam, is a state-regulated structure located in Lyndeborough, New Hampshire.
°F
°F
mph
Wind
%
Humidity
Summary
Constructed in 1977, this earth dam stands at a height of 9 feet and spans a length of 330 feet, serving primarily for flood risk reduction along the Souhegan River. With a storage capacity of 170 acre-feet and a drainage area of 4.44 square miles, the dam plays a crucial role in managing water levels and mitigating potential flooding in the region.
Managed by the NHDES Dam Bureau, Souhegan Site 8 South Dike has been assessed as having low hazard potential and a satisfactory condition, last inspected in April 2020. Despite its modest size, the dam remains a key component of the local water resource infrastructure, providing essential flood protection for the surrounding community. With a risk assessment rating of moderate, ongoing risk management measures are likely in place to ensure the continued safety and effectiveness of the structure in the face of potential climate challenges and changing hydrological conditions.
As a significant piece of New Hampshire's water management system, Souhegan Site 8 South Dike stands as a testament to the state's commitment to safeguarding its water resources and addressing the impacts of climate change. With its low hazard potential and satisfactory condition, this earth dam continues to play a vital role in protecting the local area from flooding and ensuring the resilience of the Souhegan River watershed. As climate enthusiasts and water resource advocates, understanding and monitoring structures like Souhegan Site 8 South Dike is essential for maintaining the health and sustainability of our natural water systems in the face of a changing climate.
Year Completed |
1977 |
Dam Length |
330 |
Dam Height |
9 |
River Or Stream |
TR SOUHEGAN RIVER |
Primary Dam Type |
Earth |
Surface Area |
48 |
Drainage Area |
4.44 |
Nid Storage |
170 |
Hazard Potential |
Low |
Foundations |
Unlisted/Unknown |
Nid Height |
9 |
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 South Dike
Zephyr Lake boat launch