Hancock Brook Dam Reservoir Report

Last Updated: December 20, 2025

Hancock Brook Dam, located in Waterbury, Connecticut, is a Federal-owned structure designed by CENAE and managed by the US Army Corps of Engineers.


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Summary

Completed in 1966, this earth-type dam stands at a height of 35 feet and has a maximum storage capacity of 8720 acre-feet. Its primary purpose is flood risk reduction along the Hancock Brook, with a spillway width of 100 feet to manage high discharges during storm events.

Despite its high hazard potential, the dam is regularly inspected and has an Emergency Action Plan in place, though it does not currently meet all guidelines. The US Army Corps of Engineers actively manages the dam's flood risk by monitoring its condition, prioritizing maintenance activities, and collaborating with local emergency managers to prepare for potential emergencies. The agency emphasizes public awareness and engagement to ensure readiness in case of a dam-related event, reflecting their commitment to safeguarding communities and water resources in the region.

Year Completed

1966

Dam Length

2300

Dam Height

35

River Or Stream

HANCOCK BROOK

Primary Dam Type

Earth

Surface Area

40

Hydraulic Height

30

Drainage Area

12

Nid Storage

8720

Structural Height

35

Outlet Gates

Uncontrolled - 0

Hazard Potential

High

Foundations

Rock, Soil

Nid Height

35
       
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.