Long Pond Reservoir Report

Last Updated: December 28, 2025

Long Pond, located in Somerset, Maine, is a picturesque reservoir with a primary purpose of hydroelectric power generation.


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Summary

Built in 1918, this dam stands at a height of 11.5 feet and has a storage capacity of 3007 acre-feet. The dam, constructed with concrete, earth, and gravity components, serves as a vital structure for the Federal Energy Regulatory Commission.

With a surface area of 960 acres and a drainage area of 14 square miles, Long Pond provides essential habitat for fish and wildlife. Despite its low hazard potential, the risk assessment for this dam is rated as high (2), highlighting the importance of regular inspections and emergency preparedness. While the condition assessment is currently not available, the dam is equipped with a slide gate for water release and has an inspection frequency of three years.

Long Pond serves as a key water resource in the region, contributing to both environmental conservation and energy production. As a multi-purpose dam, it showcases a blend of engineering ingenuity and ecological stewardship, making it a significant site for water resource and climate enthusiasts to explore and appreciate in the beautiful state of Maine.

Year Completed

1918

Dam Length

656

Dam Height

11.5

River Or Stream

Dole Brook

Surface Area

960

Drainage Area

14

Nid Storage

3007

Outlet Gates

Slide (sluice gate) - 1

Hazard Potential

Low

Foundations

Rock

Nid Height

12
       
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.