Quassett Lake Road Dam Reservoir Report

Last Updated: December 5, 2025

Quassett Lake Road Dam, also known as Wappaquassett Lake, is a historic masonry dam located in Woodstock, Connecticut.


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Summary

Completed in 1855, this dam stands at a height of 14 feet and has a length of 320 feet, creating a reservoir with a storage capacity of 478 acre-feet. The primary purpose of this dam is for recreation, providing a surface area of 91 acres for activities such as boating and fishing.

Despite its age and historical significance, Quassett Lake Road Dam is facing significant challenges. With a poor condition assessment and a hazard potential rated as significant, the dam requires attention to ensure its safety and functionality. The last inspection in October 2016 revealed the need for improvements, and with a moderate risk rating, there is a need for ongoing risk management measures to mitigate potential threats.

As a privately owned dam regulated by the state of Connecticut's Department of Energy and Environmental Protection (DEEP), Quassett Lake Road Dam is a crucial structure for water resource management in the area. With a spillway width of 10 feet and a maximum discharge capacity of 156 cubic feet per second, this dam plays a vital role in controlling water flow and maintaining the surrounding ecosystem. Enthusiasts of water resources and climate will be intrigued by the history and current challenges facing Quassett Lake Road Dam, highlighting the importance of sustainable dam management practices for the future.

Year Completed

1855

Dam Length

320

Dam Height

14

River Or Stream

MILL BROOK TRIB

Primary Dam Type

Masonry

Surface Area

91

Drainage Area

1.05

Nid Storage

478

Hazard Potential

Significant

Nid Height

14
       
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.