High Falls Dam At Copenhagen Reservoir Report
Nearby: Carthage State Dam West End Dam
Last Updated: December 18, 2025
High Falls Dam at Copenhagen is a privately owned concrete dam located on the Deer River in Lewis, New York.
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Summary
Completed in 1909, this hydroelectric dam stands at a height of 25 feet and spans 175 feet in length. With a maximum storage capacity of 33 acre-feet and a drainage area of 192 square miles, the dam serves as a significant structure for water resource management in the region.
The dam features an uncontrolled spillway with a width of 70 feet, posing a significant hazard potential. Although the condition assessment is not rated and the last inspection was conducted in 2008, the risk assessment is moderate (3). The dam is regulated by the New York State Department of Environmental Conservation, which oversees permitting, inspection, and enforcement to ensure its safe operation and compliance with state regulations.
High Falls Dam at Copenhagen is a noteworthy site for water resource and climate enthusiasts, offering insights into the historical development of hydroelectric infrastructure in the region. With its strategic location on the Deer River and its role in water storage and management, the dam serves as a key player in the local ecosystem and hydroelectric industry. As efforts continue to assess and manage the risks associated with the dam, its significance in the broader context of water resource management and climate resilience remains a topic of interest for researchers and stakeholders alike.
Year Completed |
1909 |
Dam Length |
175 |
Dam Height |
25 |
River Or Stream |
DEER RIVER |
Primary Dam Type |
Concrete |
Surface Area |
4 |
Drainage Area |
192 |
Nid Storage |
33 |
Hazard Potential |
Significant |
Nid Height |
25 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Beaver River At Croghan Ny
|
695cfs |
Black River At Watertown Ny
|
2330cfs |
Independence River At Donnattsburg Ny
|
214cfs |
Sandy Creek Near Adams Ny
|
212cfs |
West Branch Oswegatchie R Nr Harrisville Ny
|
322cfs |
Salmon River At Pineville Ny
|
488cfs |
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.
High Falls Dam At Copenhagen