Westminster Reservoir Dam Reservoir Report

Last Updated: December 12, 2025

Westminster Reservoir Dam, located in Westminster, Massachusetts, was completed in 1909 and serves as a critical water supply source for the area.


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Summary

Managed by a private entity, the dam stands at 31 feet high and has a hydraulic height of 23 feet, with a length of 1500 feet. The reservoir has a storage capacity of 1800 acre-feet, with a normal storage level of 870 acre-feet, covering a surface area of 116 acres and draining an area of 12.2 square miles.

The dam, primarily constructed of earth with a buttress core type, is regulated by the Department of Conservation and Recreation in Massachusetts and undergoes regular inspections with a fair condition assessment as of April 2017. With a high hazard potential and a moderate risk assessment score of 3, the dam is considered a crucial piece of infrastructure for water resource management in the region. Despite its age, the Westminster Reservoir Dam continues to play a vital role in ensuring water supply reliability and management for the surrounding communities.

In the event of an emergency, the dam is equipped with an uncontrolled spillway type, although no outlet gates or locks are present. With a history of modifications unlisted, the dam remains a key component in the overall risk management strategy for water resources in the area. As water resource and climate enthusiasts, understanding the importance of infrastructure like the Westminster Reservoir Dam is critical for maintaining the resilience and sustainability of water systems in the face of changing environmental conditions.

Year Completed

1909

Dam Length

1500

Dam Height

31

River Or Stream

WHITMAN RIVER

Primary Dam Type

Earth

Surface Area

116

Hydraulic Height

23

Drainage Area

12.2

Nid Storage

1800

Hazard Potential

High

Foundations

Unlisted/Unknown

Nid Height

31
       
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.