Hopkinton

Contoocook River· Merrimack, New Hampshire· Built 1890· Concrete· 10 ft tall
Low Hazard Hydroelectric Local Government

Key Takeaway

Hopkinton is classified as low hazard in New Hampshire. It was completed in 1890 and is 136 years old. Its primary use is hydroelectric.

Physical Details

Dam Height 10 ft (taller than 16% in NH)
Dam Length325 ft
Dam TypeConcrete
Max Storage380 acre-ft
Normal Storage380 acre-ft
Surface Area110 acres
Drainage Area437 sq mi
Max Discharge7,000 cfs
Year Completed1890 (136 years old)
NID IDNH00204

Safety Information

Low Hazard

No probable loss of human life and low economic/environmental losses expected.

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

Emergency Action Plan: No
Last Inspection: July 26, 2018
State Regulated: Yes
Regulatory Agency: NHDES DAM BUREAU

Ownership

Town of Hopkinton, NH

Local Government

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Hopkinton?

Hopkinton is classified as Low Hazard. No probable loss of human life and low economic/environmental losses expected. This classification refers to the potential downstream consequences of a failure, not the dam's current structural condition.

Who owns and operates Hopkinton?

Hopkinton is owned by Town of Hopkinton, NH (Local Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Hopkinton built?

Hopkinton was completed in 1890, making it 136 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 Hopkinton?

Hopkinton 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 Hopkinton?

Hopkinton has a dam height of 10 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 Hopkinton last inspected?

Hopkinton was last inspected on July 26, 2018. 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.