Heuvelton Reservoir Report
Nearby: Eel Weir Upper & Lower Lakes Dam #1
Last Updated: January 2, 2026
Heuvelton, a privately-owned hydroelectric dam located in St.
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Summary
Lawrence County, New York, along the Oswegatchie River, stands as a testament to engineering excellence since its completion in 1923. With a concrete multi-arch design and a significant structural height of 7 feet, the dam serves a primary purpose of hydroelectric power generation. The dam boasts a maximum storage capacity of 405 acre-feet and covers a surface area of 239 acres, drawing water from a drainage area of 995 square miles.
The dam's spillway, controlled by a width of 168 feet, ensures efficient water discharge at a maximum rate of 23,000 cubic feet per second. Despite its impressive capabilities, Heuvelton is classified with a significant hazard potential, prompting stringent inspection protocols by the Federal Energy Regulatory Commission. The dam's risk assessment rates it as very high, highlighting the critical importance of effective risk management measures to safeguard against potential emergencies and ensure the dam's continued safe operation for the surrounding community.
In the care of the Federal Energy Regulatory Commission, Heuvelton undergoes regular inspections and emergency action plan updates to mitigate risks and respond promptly to any unforeseen events. The dam's enduring presence and vital role in hydroelectric power generation underscore its significance as a key player in water resource management and climate adaptation efforts. As a focal point for water resource and climate enthusiasts, Heuvelton represents a harmonious blend of human ingenuity and environmental stewardship in harnessing the power of water for sustainable energy production.
Year Completed |
1923 |
Dam Length |
284 |
Dam Height |
19 |
River Or Stream |
Oswegatchie River |
Primary Dam Type |
Concrete |
Surface Area |
239 |
Hydraulic Height |
34.9 |
Drainage Area |
995 |
Nid Storage |
405 |
Structural Height |
7 |
Outlet Gates |
Other Controlled - 2, Tainter (radial) - 4 |
Hazard Potential |
Significant |
Foundations |
Rock |
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.
Heuvelton
Maple City Trail Ogdensburg