Allen Reservoir Pl-566 Flood Control Dam

Allen Reservoir Pl-566 Flood Control Dam is an earth dam located in Norfolk County, Massachusetts, built in 1981. It carries a High hazard potential classification and has a satisfactory condition assessment.

About Allen Reservoir Pl-566 Flood Control Dam

The primary purpose of Allen Reservoir Pl-566 Flood Control Dam is flood risk reduction. The dam is designed to control downstream flooding by temporarily storing excess water during storms and releasing it at a controlled rate. The dam is owned by Town Of Walpole (local government). It impounds the Spring Brook near Walpole.

The dam stands 21 feet tall and stretches 1,500 feet across, creates a reservoir covering 12 acres, has a maximum storage capacity of 240 acre-feet, and collects water from a drainage area of 1 square miles. Completed in 1981, the structure is 45 years old.

This dam carries a high hazard potential classification, which means that a failure or uncontrolled release of water would likely cause loss of human life. This classification reflects the consequences of failure, not the likelihood — it indicates that people live or work in the area downstream. Its condition is rated satisfactory, indicating no existing or potential dam safety deficiencies are recognized. An emergency action plan is in place for this dam. The most recent inspection on record was 03/31/2023.

Living Downstream

If you live or work downstream of this dam, consider taking these steps: learn your local evacuation routes, check whether your county emergency management office has a dam failure inundation map, and sign up for local emergency alerts. The Massachusetts dam safety program can provide more specific information about emergency planning for this structure.

Search for dams near your address to see all dams in your area with hazard classifications and safety data.

High HazardSatisfactory ConditionEmergency Action Plan: Yes

Location

StateMassachusetts
CountyNorfolk
Nearest CityWalpole
River/StreamSpring Brook
Coordinates42.13574, -71.23736

Physical Characteristics

Dam TypeEarth
NID Height21 ft
Dam Length1,500 ft
Year Completed1981 (45 years old)

Storage & Hydraulics

NID Storage240 acre-ft
Max Storage240 acre-ft
Normal Storage43 acre-ft
Surface Area12 acres
Drainage Area1 sq mi
Spillway TypeUncontrolled

Ownership & Safety

PurposeFlood Risk Reduction
OwnerTown of Walpole
Owner TypeLocal Government
Hazard ClassificationHigh
Condition AssessmentSatisfactory
Last Inspection03/31/2023
Emergency Action PlanYes

Identifiers

NID IDMA03210
Federal IDMA03210
More InfoState Dam Safety Program

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