Effley Reservoir Report

Last Updated: December 19, 2025

Effley, also known as Effley Falls Pond Dam, is a private hydroelectric structure located in Belfort, New York.


°F

°F

mph

Wind

%

Humidity

Summary

Built in 1902, this concrete dam stands at a height of 30 feet and spans 1247 feet along the Beaver River. With a storage capacity of 3140 acre-feet and a surface area of 340 acres, Effley plays a crucial role in harnessing the power of water for electricity generation.

Managed by the Federal Energy Regulatory Commission, Effley has a spillway width of 430 feet and a maximum discharge capacity of 17,300 cubic feet per second. Despite its high hazard potential, the dam is not state-regulated and is inspected by FERC on a regular basis. With its unique multi-arch core design and rock foundation, Effley exemplifies engineering excellence in water resource management and climate resilience.

Effley's association with renewable energy production and water conservation makes it a notable landmark in Lewis County, New York. As climate enthusiasts and water resource advocates, understanding the intricate design and operational aspects of structures like Effley is essential for promoting sustainable infrastructure development and mitigating the impacts of climate change on our water resources.

Year Completed

1902

Dam Length

1247

Dam Height

30

River Or Stream

Beaver River

Primary Dam Type

Concrete

Surface Area

340

Drainage Area

249

Nid Storage

3140

Outlet Gates

Slide (sluice gate) - 2

Hazard Potential

High

Foundations

Rock

Nid Height

30
       
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.