James Thompson Reservoir Report
Nearby: Schaghticoke Tomhannock Reservoir Dam
Last Updated: December 15, 2025
Located in Valley Falls, New York, the James Thompson Dam, also known as the Hoosic River Dam, is a private structure regulated by the New York State Department of Environmental Conservation.
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Summary
Completed in 1927, this concrete gravity dam stands at 18.5 feet high and spans 218 feet in length. Its primary purpose is hydroelectric generation, with a normal storage capacity of 280 acre-feet and a maximum discharge rate of 10,800 cubic feet per second.
Managed by the Federal Energy Regulatory Commission, the James Thompson Dam boasts a low hazard potential and moderate risk assessment rating. While its condition assessment is currently listed as "Not Available," the dam is subject to regular inspections by both federal and state agencies. Despite its age, the dam continues to serve as a vital component of the local water resource infrastructure, supporting the Hoosic River and surrounding area with its controlled spillway and rock foundation.
For water resource and climate enthusiasts, the James Thompson Dam presents an intriguing case study of a historic structure maintaining its functionality and safety standards in the modern era. With its moderate risk level and established emergency action plan, the dam exemplifies the importance of proactive management and regulatory oversight in ensuring the resilience of hydroelectric facilities in the face of changing environmental conditions and evolving safety standards.
Year Completed |
1927 |
Dam Length |
218 |
Dam Height |
18.5 |
River Or Stream |
Hoosic River |
Primary Dam Type |
Concrete |
Surface Area |
70 |
Drainage Area |
630 |
Nid Storage |
280 |
Hazard Potential |
Low |
Foundations |
Rock |
Nid Height |
19 |
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.
James Thompson
Hudson River Road 951, City of Mechanicville