Amoskeag

Merrimack River· Hillsborough, New Hampshire· Built 1921· Concrete· 29 ft tall
High Hazard Hydroelectric Not Listed

Key Takeaway

Amoskeag is classified as high hazard in New Hampshire. It was completed in 1921 and is 105 years old. Its primary use is hydroelectric. 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 29 ft (taller than 86% in NH)
Dam Length1,075 ft
Dam TypeConcrete
Max Storage4.3K acre-ft
Normal Storage4.3K acre-ft
Surface Area478 acres
Drainage Area2,854 sq mi
Max Discharge87,000 cfs
Year Completed1921 (105 years old)
NID IDNH00102

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: September 7, 2022
State Regulated: Yes
Regulatory Agency: NHDES DAM BUREAU

Ownership

Not Listed

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Amoskeag?

Amoskeag 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 Amoskeag?

Amoskeag is owned by information not available (Not Listed). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Amoskeag built?

Amoskeag 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 Amoskeag?

Amoskeag 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 Amoskeag?

Amoskeag has a dam height of 29 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 Amoskeag last inspected?

Amoskeag was last inspected on September 7, 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.