Holyoke Dam

Connecticut River· Hampshire, Massachusetts· Built 1900· Masonry· 30 ft tall
Significant Hazard Hydroelectric Recreation Local Government

Key Takeaway

Holyoke Dam is classified as significant hazard in Massachusetts. It was completed in 1900 and is 126 years old. Its primary use is hydroelectric. Significant hazard means failure could cause economic or environmental damage. Learn more.

Physical Details

Dam Height 30 ft (taller than 86.6% in MA)
Dam Length1,770 ft
Dam TypeMasonry
Max Storage26.0K acre-ft
Normal Storage26.0K acre-ft
Surface Area2,290 acres
Drainage Area8,309 sq mi
Max Discharge251,400 cfs
Year Completed1900 (126 years old)
NID IDMA00973

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: August 11, 2022
State Regulated: No

Ownership

City of Holyoke Gas and Electric Department

Local Government

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Holyoke Dam?

Holyoke 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 Holyoke Dam?

Holyoke Dam is owned by City of Holyoke Gas and Electric Department (Local Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Holyoke Dam built?

Holyoke Dam was completed in 1900, making it 126 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 Holyoke Dam?

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

How tall is Holyoke Dam?

Holyoke Dam has a dam height of 30 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 Holyoke Dam last inspected?

Holyoke Dam was last inspected on August 11, 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.