Cobbs Pond Dam

COBBS BROOK WHICH FLOWS INTO NEPONSET RIVER· Norfolk, Massachusetts· Masonry· 12 ft tall

High Hazard Flood Risk Reduction Recreation Local Government

Key Takeaway

Cobbs Pond Dam is classified as high hazard in Massachusetts. Its primary use is flood risk reduction. High hazard means loss of life is likely if the dam fails — it does not indicate the dam's current condition. Learn more.

Physical Details

Dam Height	12 ft (taller than 32.1% in MA)
Dam Length	220 ft
Dam Type	Masonry
Max Storage	240 acre-ft
Normal Storage	30 acre-ft

Surface Area	13 acres
Drainage Area	2 sq mi
NID ID	MA02482

Safety Information

High Hazard

Loss of human life is likely if the dam fails.

Hazard potential describes downstream consequences of failure, not the dam's current condition. What does this mean?

Emergency Action Plan: Yes

Last Inspection: April 11, 2017

State Regulated: Yes

Regulatory Agency: DEPARTMENT OF CONSERVATION AND RECREATION

Ownership

TOWN OF WALPOLE, DEPARTMENT OF PUBLIC WORKS

Local Government

Nearby Dams

Plimpton Pond Dam

Norfolk, MA

Low Hazard 19 ft

Memorial Pond Dam

Norfolk, MA

Significant Hazard 11 ft

Diamond Pond Dam

Norfolk, MA

Significant Hazard 10 ft

Kendall Mill Dam

Norfolk, MA

Significant Hazard 8 ft

Turner Pond Dam

Norfolk, MA

Significant Hazard 10 ft

Allen Reservoir PL-566 Flood Control Dam

Norfolk, MA

High Hazard 21 ft

Willett Pond Dam

Norfolk, MA

High Hazard 25 ft

Neponset River Dam

Norfolk, MA

Low Hazard 15 ft

Frequently Asked Questions

What is the hazard classification of Cobbs Pond Dam?

Cobbs Pond Dam is classified as High Hazard. Loss of human life is likely if the dam fails. This classification refers to the potential downstream consequences of a failure, not the dam's current structural condition.

Who owns and operates Cobbs Pond Dam?

Cobbs Pond Dam is owned by TOWN OF WALPOLE, DEPARTMENT OF PUBLIC WORKS (Local Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

What is the primary purpose of Cobbs Pond Dam?

Cobbs Pond Dam serves the following purposes: Flood Risk Reduction, Recreation. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.

How tall is Cobbs Pond Dam?

Cobbs Pond Dam has a dam height of 12 ft. Dam height is measured from the natural streambed at the downstream toe to the top of the dam, and may differ from the visible height.

When was Cobbs Pond Dam last inspected?

Cobbs Pond Dam was last inspected on April 11, 2017. Inspection dates indicate when a formal review occurred, not the results of that inspection.

Data from the National Inventory of Dams (NID) maintained by the US Army Corps of Engineers. Dam conditions may have changed since the last update. This site is not affiliated with USACE. Do not use for emergency planning — contact your local dam safety program.