Mill River Dam

MILL RIVER DIVERSION· Hampshire, Massachusetts· Built 1939· Concrete· 40 ft tall
Significant Hazard Other Local Government

Key Takeaway

Mill River Dam is classified as significant hazard in Massachusetts. It was completed in 1939 and is 87 years old. Its primary use is other. Significant hazard means failure could cause economic or environmental damage. Learn more.

Physical Details

Dam Height 40 ft (taller than 92.4% in MA)
Dam Length450 ft
Dam TypeConcrete
Max Storage165 acre-ft
Normal Storage26 acre-ft
Surface Area13 acres
Drainage Area54 sq mi
Year Completed1939 (87 years old)
NID IDMA01010

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: July 21, 2015
State Regulated: Yes
Regulatory Agency: DEPARTMENT OF CONSERVATION AND RECREATION

Ownership

CITY OF NORTHAMPTON, DEPARTMENT OF PUBLIC WORKS

Local Government

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Mill River Dam?

Mill River 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 Mill River Dam?

Mill River Dam is owned by CITY OF NORTHAMPTON, DEPARTMENT OF PUBLIC WORKS (Local Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Mill River Dam built?

Mill River Dam was completed in 1939, making it 87 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 Mill River Dam?

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

How tall is Mill River Dam?

Mill River Dam has a dam height of 40 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 Mill River Dam last inspected?

Mill River Dam was last inspected on July 21, 2015. 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.