Lake Winnemaug Dam Reservoir Report

Last Updated: December 5, 2025

Lake Winnemaug Dam, located in Oakville, Connecticut, serves as a vital recreational resource for the local community.


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Summary

Built in 1920, this earth dam stands at 24 feet high and spans 500 feet in length, creating a reservoir with a storage capacity of 1050 acre-feet. The dam's primary purpose is for recreation, offering a surface area of 122 acres for activities such as boating, fishing, and picnicking.

Managed by the local government and regulated by the Connecticut Department of Energy and Environmental Protection (DEEP), Lake Winnemaug Dam has a high hazard potential due to its location on Wattles Brook. Despite this, the dam is in satisfactory condition and undergoes inspections every two years to ensure its safety and functionality. The spillway, with a width of 19 feet, provides an uncontrolled release of water in the event of excess storage, with a maximum discharge capacity of 774 cubic feet per second.

With its historical significance and importance as a recreational hub, Lake Winnemaug Dam stands as a testament to the intersection of water resource management and climate resilience. As climate change continues to impact water systems, the careful monitoring and maintenance of dams like Lake Winnemaug become increasingly crucial to ensure the safety of both the environment and the surrounding community.

Year Completed

1920

Dam Length

500

Dam Height

24

River Or Stream

WATTLES BROOK

Primary Dam Type

Earth

Surface Area

122

Drainage Area

1.1

Nid Storage

1050

Hazard Potential

High

Nid Height

24
       
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.