Poheganut Reservoir Dam Reservoir Report

Last Updated: December 5, 2025

The Poheganut Reservoir Dam, located in Groton, Connecticut, is a significant earth dam completed in 1952 primarily for water supply purposes.


°F

°F

mph

Wind

%

Humidity

Summary

The dam stands at a height of 16 feet and has a length of 1078 feet, providing a storage capacity of 687 acre-feet with a normal storage level of 687 acre-feet. Situated on the Hatching House Brook, the dam is regulated by the state and undergoes regular inspections to ensure its structural integrity.

Owned by the local government, the Poheganut Reservoir Dam poses a significant hazard potential but has been assessed to be in satisfactory condition as of November 2014. With a spillway width of 60 feet and a surface area of 108 acres, the dam plays a crucial role in managing water resources in the area. Despite its age, the dam continues to serve its purpose effectively, highlighting the importance of proper maintenance and regulatory oversight in ensuring the safety of water infrastructure.

Managed by the Department of Energy and Environmental Protection (DEEP) in Connecticut, the Poheganut Reservoir Dam serves as a vital component of the local water supply system. With a history dating back to the mid-20th century, the dam's operations are closely monitored to mitigate risks and ensure the safety of surrounding communities. As climate change poses new challenges to water resources management, the resilience of structures like the Poheganut Reservoir Dam becomes increasingly crucial in adapting to a changing environment.

Year Completed

1952

Dam Length

1078

Dam Height

16

River Or Stream

HATCHING HOUSE BK

Primary Dam Type

Earth

Surface Area

108

Drainage Area

1.43

Nid Storage

687

Hazard Potential

Significant

Nid Height

16
       
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.