Cocassett Lake Dam

COCASSETT RIVER· Norfolk, Massachusetts· Built 1886· Earth· 16 ft tall
Significant Hazard Recreation Private

Key Takeaway

Cocassett Lake Dam is classified as significant hazard in Massachusetts. It was completed in 1886 and is 140 years old. Its primary use is recreation. Significant hazard means failure could cause economic or environmental damage. Learn more.

Physical Details

Dam Height 16 ft (taller than 56.3% in MA)
Dam Length350 ft
Dam TypeEarth
Max Storage215 acre-ft
Normal Storage180 acre-ft
Surface Area32 acres
Drainage Area3 sq mi
Year Completed1886 (140 years old)
NID IDMA00817

Safety Information

Significant Hazard

No probable loss of human life, but can cause economic loss, environmental damage, or disruption of lifeline facilities.

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

Emergency Action Plan: No
Last Inspection: September 28, 2017
State Regulated: Yes
Regulatory Agency: DEPARTMENT OF CONSERVATION AND RECREATION

Ownership

COCASSETT LAKE ASSOCIATION, INC.

Private

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Cocassett Lake Dam?

Cocassett Lake Dam is classified as Significant Hazard. No probable loss of human life, but can cause economic loss, environmental damage, or disruption of lifeline facilities. This classification refers to the potential downstream consequences of a failure, not the dam's current structural condition.

Who owns and operates Cocassett Lake Dam?

Cocassett Lake Dam is owned by COCASSETT LAKE ASSOCIATION, INC. (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Cocassett Lake Dam built?

Cocassett Lake Dam was completed in 1886, making it 140 years old. Many U.S. dams were built between the 1930s and 1970s during a period of major infrastructure investment.

What is the primary purpose of Cocassett Lake Dam?

Cocassett Lake Dam serves the following purposes: Recreation. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.

How tall is Cocassett Lake Dam?

Cocassett Lake Dam has a dam height of 16 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 Cocassett Lake Dam last inspected?

Cocassett Lake Dam was last inspected on September 28, 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.