Assabet

Assabet River· Middlesex, Massachusetts· Built 1921· Masonry· 13 ft tall
Significant Hazard Hydroelectric Private

Key Takeaway

Assabet is classified as significant hazard in Massachusetts. It was completed in 1921 and is 105 years old. Its primary use is hydroelectric. Significant hazard means failure could cause economic or environmental damage. Learn more.

Physical Details

Dam Height 13 ft (taller than 39.5% in MA)
Dam Length480 ft
Dam TypeMasonry
Max Storage122 acre-ft
Normal Storage122 acre-ft
Surface Area30 acres
Drainage Area123 sq mi
Max Discharge3,350 cfs
Year Completed1921 (105 years old)
NID IDMA00128

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: Yes
Last Inspection: June 16, 2022
State Regulated: No

Ownership

Acton Hydro Company, Inc.

Private

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Assabet?

Assabet 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 Assabet?

Assabet is owned by Acton Hydro Company, Inc. (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Assabet built?

Assabet was completed in 1921, making it 105 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 Assabet?

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

How tall is Assabet?

Assabet has a dam height of 13 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 Assabet last inspected?

Assabet was last inspected on June 16, 2022. 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.