Otis Reservoir Dam Reservoir Report

Last Updated: December 7, 2025

The Otis Reservoir Dam in Massachusetts, completed in 2012, stands at a height of 31.5 feet and serves as a vital structure for managing water resources in the region.


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Summary

The dam, primarily designated for Fish and Wildlife Pond purposes, has a normal storage capacity of 22,000 acre-feet and a surface area of 1,000 acres. The reservoir provides recreational opportunities while also supporting the local ecosystem by serving as a habitat for various fish and wildlife species.

Managed by the Department of Conservation and Recreation, the Otis Reservoir Dam is inspected regularly to ensure its structural integrity and safety. With a high hazard potential due to its proximity to the Fall River, the dam is classified as having a satisfactory condition assessment. Emergency action plans are in place to mitigate risks in case of any unforeseen events, with the last plan revision dated back to 2013. The dam's risk assessment is moderate, indicating the need for ongoing monitoring and management measures.

Located in Berkshire, Massachusetts, the Otis Reservoir Dam plays a crucial role in water resource management and climate resilience efforts in the region. With its masonry construction and uncontrolled spillway type, the dam not only helps regulate water flow but also contributes to the overall environmental health of the area. As a state-regulated structure, the dam's operations are closely monitored to ensure the safety of surrounding communities and the preservation of the reservoir's ecological balance.

Year Completed

2012

Dam Length

630

Dam Height

31.5

River Or Stream

FALL RIVER

Primary Dam Type

Masonry

Surface Area

1000

Hydraulic Height

27

Drainage Area

16

Nid Storage

27500

Hazard Potential

High

Foundations

Unlisted/Unknown

Nid Height

32
       
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.