Mechanic Falls Reservoir Report

Last Updated: December 14, 2025

Mechanic Falls, also known as Marcal Dam, is a private-owned structure located in Mechanic Falls, Maine along the Little Androscoggin River.


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Summary

Built in 1866, this masonry dam stands at a height of 15.4 feet and has a storage capacity of 103 acre-feet. The dam serves a primary purpose of hydroelectric power generation and is regulated by the Federal Energy Regulatory Commission.

With a low hazard potential and a moderate risk assessment rating, Mechanic Falls is considered to be in a stable condition. The dam features an uncontrolled spillway with a width of 126 feet and an outlet gate consisting of a slide (sluice gate). Despite not being state-regulated or inspected, the Federal Energy Regulatory Commission oversees the operations and inspections of this historical dam.

Water resource and climate enthusiasts will find Mechanic Falls to be an intriguing site with its rich history, unique design features, and contribution to hydroelectric power generation. The dam's location along the scenic Little Androscoggin River adds to its charm, making it a noteworthy structure in the region.

Year Completed

1866

Dam Length

172

Dam Height

15.4

River Or Stream

Little Androscoggin River

Primary Dam Type

Masonry

Surface Area

27

Drainage Area

250

Nid Storage

103

Outlet Gates

Slide (sluice gate) - 1

Hazard Potential

Low

Foundations

Rock

Nid Height

15
       
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.