North Lake B Dam Reservoir Report
Last Updated: December 14, 2025
North Lake B Dam, located in Atwell, Herkimer, New York, is a state-owned structure with a primary purpose of navigation along the TR-BLACK RIVER.
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Summary
Built in 1850, this earth dam stands at a height of 35 feet and stretches 575 feet in length. It provides a storage capacity of 6190 acre-feet with a surface area of 442 acres, making it an essential component for managing water resources in the region.
Although the dam has a low hazard potential, its risk assessment is rated as high due to various factors that warrant attention. Despite not being recently inspected or rated for condition assessment, the dam remains under state regulation and inspection by the New York State Department of Environmental Conservation. With a maximum discharge capacity of 5590 cubic feet per second, the dam plays a crucial role in maintaining water levels and ensuring the safety of surrounding areas.
While North Lake B Dam is not currently associated with any other structures or federal agencies, its significance lies in its contribution to navigation and water management in the area. As climate change continues to impact water resources, this dam serves as a vital piece of infrastructure that requires ongoing monitoring and maintenance to mitigate potential risks and ensure its continued effectiveness in the face of evolving environmental challenges.
Year Completed |
1850 |
Dam Length |
575 |
Dam Height |
35 |
River Or Stream |
TR-BLACK RIVER |
Primary Dam Type |
Earth |
Surface Area |
442 |
Nid Storage |
6190 |
Hazard Potential |
Low |
Nid Height |
35 |
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.
North Lake B Dam