Lock E-18 Dam Herkimer Reservoir Report

Last Updated: December 7, 2025

Lock E-18 Dam in Herkimer, New York, serves as a critical flood risk reduction structure along the Erie Canal and Mohawk River.


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Summary

Built in 1915, this state-regulated dam stands at a height of 6 feet and has a storage capacity of 2200 acre-feet. With a controlled spillway width of 350 feet, the dam plays a crucial role in mitigating the risk of flooding in the region.

Managed by the New York State Department of Environmental Conservation, Lock E-18 Dam is classified as a significant hazard potential structure with a very high risk assessment rating. Despite not being conditionally rated, the dam undergoes inspection every four years to ensure its structural integrity and effectiveness in flood control. Situated in Herkimer County, this dam is a key component in the state's flood risk reduction and navigation efforts along the Mohawk River.

The presence of Lock E-18 Dam highlights the state's commitment to managing water resources and protecting communities from the impacts of extreme weather events. Its strategic location and design make it a vital asset in safeguarding the surrounding areas from potential flooding, showcasing the importance of robust infrastructure in addressing climate-related challenges.

Year Completed

1915

Dam Length

400

Dam Height

6

River Or Stream

ERIE CANAL MOHAWK RIVER

Primary Dam Type

Other

Surface Area

420

Nid Storage

2200

Hazard Potential

Significant

Nid Height

6
       
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.