Pyrites Intake Reservoir Report
Nearby: Upper & Lower Lakes Dam #1 Hannawa
Last Updated: January 1, 2026
Pyrites Intake, located in Canton, New York, is a private hydroelectric dam on the Grass River, constructed in 1908.
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Summary
With a dam height of 27 feet and a length of 385 feet, it serves as a crucial water resource in St. Lawrence County. Managed by the Federal Energy Regulatory Commission, the dam has a low hazard potential but is classified as having a high risk assessment level (2).
Despite its age, Pyrites Intake has not undergone recent condition assessments, and its emergency action plan was last revised in 2014. The dam's primary purpose is hydroelectric power generation, with a storage capacity of 27 acre-feet. While it lacks a spillway, the dam's multi-arch concrete structure and rock foundation contribute to its structural integrity. The surrounding area covers 5.3 square miles, with a drainage area of 333 square miles.
Overall, Pyrites Intake plays a vital role in the local water resource management and climate considerations. As a key component of the New York District, the dam's operation and maintenance are overseen by federal agencies to ensure the safety and sustainability of its hydroelectric functions. With the potential for high risk, continued monitoring and assessment are essential to safeguarding the surrounding community and environment from any unforeseen hazards.
Year Completed |
1908 |
Dam Length |
385 |
Dam Height |
27 |
River Or Stream |
Grass River |
Primary Dam Type |
Concrete |
Surface Area |
5.3 |
Drainage Area |
333 |
Nid Storage |
27 |
Hazard Potential |
Low |
Foundations |
Rock |
Nid Height |
27 |
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.
Pyrites Intake