Colrain Lower Reservoir Dam Reservoir Report

Last Updated: December 5, 2025

The Colrain Lower Reservoir Dam, located in Franklin County, Massachusetts, was completed in 1902 and serves multiple purposes including fire protection and providing a small fish pond for the local community.


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Summary

The dam, primarily made of concrete with a buttress core type, stands at 15 feet high with a hydraulic height of 14 feet. The reservoir has a storage capacity of 3 acre-feet and covers a surface area of 0.28 acres, with a drainage area of 0.34 acres. The dam is regulated and inspected by the Department of Conservation and Recreation in Massachusetts.

Despite being rated as having a significant hazard potential, the Colrain Lower Reservoir Dam is currently in fair condition, based on a 2012 assessment. The dam has an inspection frequency of 5 years and is in a moderate risk category with a risk rating of 3. While the dam does not have an Emergency Action Plan (EAP) in place, it meets state regulatory requirements for inspection, enforcement, and permitting. The dam does not have a spillway, indicating an uncontrolled release of water in case of overflow.

The Colrain Lower Reservoir Dam, nestled in the town of Colrain, plays a crucial role in providing emergency water supply and recreational opportunities for the local community. With its historical significance and important functions, the dam continues to be a focal point for water resource and climate enthusiasts interested in the management and maintenance of dams in Massachusetts.

Year Completed

1902

Dam Length

85

Dam Height

15

River Or Stream

EAST BROOK

Primary Dam Type

Concrete

Surface Area

0.28

Hydraulic Height

14

Drainage Area

0.34

Nid Storage

3

Hazard Potential

Significant

Foundations

Unlisted/Unknown

Nid Height

15
       
Seasonal Comparison

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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.