South Berwick Reservoir Report
Nearby: South Berwick Rollinsford
Last Updated: December 19, 2025
South Berwick, also known as the Salmon Falls River Dam No.1, is a privately owned hydroelectric dam located in New Hampshire.
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Summary
Built in 1923, this concrete gravity dam stands at 18 feet tall and spans 290 feet in length. It has a storage capacity of 641 acre-feet and serves the primary purpose of generating hydroelectric power. The dam is regulated by the New Hampshire Department of Environmental Services Dam Bureau and inspected by the Federal Energy Regulatory Commission.
This dam on the Salmon Falls River has a low hazard potential and a moderate risk assessment rating. It features an uncontrolled spillway with a width of 220 feet and two slide (sluice gate) outlet gates. The surrounding area has a surface area of 58 acres and a drainage area of 235 square miles. Despite its age, the dam has not undergone any recent condition assessments, but it is subject to regular inspections and enforcement to ensure its structural integrity and safety for the community.
South Berwick plays a crucial role in the local water resource management and climate resilience efforts, providing clean energy and flood control benefits to the region. With its historical significance and ongoing operational importance, this hydroelectric dam serves as a key infrastructure asset in the state's renewable energy portfolio and water resource management strategy. As enthusiasts of water resources and climate change, it is vital to monitor and support the sustainable operation of dams like South Berwick to ensure a resilient and environmentally friendly future for generations to come.
Year Completed |
1923 |
Dam Length |
290 |
Dam Height |
18 |
River Or Stream |
Salmon Falls River |
Primary Dam Type |
Concrete |
Surface Area |
58 |
Drainage Area |
235 |
Nid Storage |
641 |
Outlet Gates |
Slide (sluice gate) - 2 |
Hazard Potential |
Low |
Nid Height |
18 |
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.
South Berwick
Salmon Falls River boat launch