Bonny Eagle Reservoir Report

Last Updated: December 13, 2025

Bonny Eagle, also known as the Main River Channel Dam, is a privately owned hydroelectric structure located in Hollis, Maine.


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Summary

Built in 1911 by J. G. White & Co., this concrete dam stands at a height of 67 feet and spans a length of 784 feet. It has a storage capacity of 2,320 acre-feet and serves multiple purposes including hydroelectric generation and recreation.

Managed by the Federal Energy Regulatory Commission, Bonny Eagle has a low hazard potential and a high risk assessment rating of 2. Despite being non-state regulated, the dam undergoes periodic inspections with a frequency of every 3 years. With a surface area of 347 acres and a drainage area of 1,563 square miles, the dam plays a crucial role in water resource management in the region.

Although lacking a spillway, Bonny Eagle is equipped with a flap outlet gate to control water flow. While its current condition assessment is not available, efforts have been made to prepare emergency action plans and assess risk management measures. With its historical significance and ongoing role in providing renewable energy, Bonny Eagle remains a vital component in the local water infrastructure and climate resilience efforts.

Year Completed

1911

Dam Length

784

Dam Height

67

River Or Stream

Saco River

Primary Dam Type

Concrete

Surface Area

347

Drainage Area

1563

Nid Storage

2320

Outlet Gates

Flap - 1

Hazard Potential

Low

Nid Height

67
       
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.