Sewalls South Channel Dam Reservoir Report

Last Updated: December 5, 2025

Located in Watertown, New York, the Sewalls South Channel Dam is a private hydroelectric structure situated on the Black River.


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Summary

Constructed in 1978, this concrete dam stands at a height of 16 feet and spans 243 feet in length. With a storage capacity of 388 acre-feet, the dam serves as a vital component in the region's water resource management and energy production.

Despite being privately owned, the Sewalls South Channel Dam falls under state jurisdiction, with regular inspections conducted to ensure its structural integrity and operational safety. With a significant hazard potential and moderate risk assessment rating, the dam plays a crucial role in flood control and water regulation within the area. While its condition remains unrated, efforts are made to maintain the dam's effectiveness in mitigating potential risks and ensuring its continued functionality for the community.

With a primary purpose of hydroelectric power generation, the Sewalls South Channel Dam not only contributes to the local energy supply but also plays a role in water conservation and management. As a key feature in the region's water infrastructure, the dam serves as a reminder of the interconnectedness between water resources and climate considerations, highlighting the importance of sustainable practices in harnessing the power of nature for the benefit of society.

Year Completed

1978

Dam Length

243

Dam Height

16

River Or Stream

BLACK RIVER

Primary Dam Type

Concrete

Surface Area

13

Drainage Area

1875

Nid Storage

388

Hazard Potential

Significant

Nid Height

16
       
Seasonal Comparison

Weather Forecast

Dam Data Reference

Condition Assessment

Satisfactory
No 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

High
Dams 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.