Rail Joint Mill Dam Reservoir Report

Last Updated: December 20, 2025

Rail Joint Mill Dam, also known as Portec Dam, is a historic masonry dam located in Troy, New York, along the WYNANTSKILL river.


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Summary

Built in 1903 for irrigation purposes, the dam stands at 25 feet high and spans 165 feet in length. Despite its age and significant hazard potential, the dam is in poor condition as of the last assessment in April 2019.

Managed by the local government and regulated by the NYS DEC, Rail Joint Mill Dam has a storage capacity of 10 acre-feet and a spillway width of 150 feet. Its uncontrolled spillway type poses a moderate risk, with a risk assessment rating of 3. The dam's emergency action plan status and adherence to guidelines remain unclear, raising concerns about its ability to handle potential disasters and inundation events.

With its rich history and vital role in irrigation, Rail Joint Mill Dam serves as a focal point for water resource and climate enthusiasts interested in the preservation and management of aging infrastructure. The dam's current condition, inspection frequency, and risk assessment highlight the need for ongoing monitoring and potential rehabilitation efforts to ensure the safety and functionality of this important water resource structure.

Year Completed

1903

Dam Length

165

Dam Height

25

River Or Stream

WYNANTSKILL

Primary Dam Type

Masonry

Surface Area

1

Nid Storage

10

Hazard Potential

Significant

Nid Height

25
       
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.