Hargate Dam

TURKEY RIVER· Merrimack, New Hampshire· Built 1835· Concrete· 14 ft tall
Low Hazard Recreation Private

Key Takeaway

Hargate Dam is classified as low hazard in New Hampshire. It was completed in 1835 and is 191 years old. Its primary use is recreation.

Physical Details

Dam Height 14 ft (taller than 42.1% in NH)
Dam Length119 ft
Dam TypeConcrete
Max Storage221 acre-ft
Normal Storage31 acre-ft
Surface Area46 acres
Drainage Area31 sq mi
Max Discharge1,957 cfs
Year Completed1835 (191 years old)
Year Modified2007
NID IDNH00484

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: November 4, 2020
State Regulated: Yes
Regulatory Agency: NH DES

Ownership

ST PAULS SCHOOL

Private

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Hargate Dam?

Hargate Dam 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 Hargate Dam?

Hargate Dam is owned by ST PAULS SCHOOL (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Hargate Dam built?

Hargate Dam was completed in 1835, making it 191 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 Hargate Dam?

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

How tall is Hargate Dam?

Hargate Dam has a dam height of 14 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 Hargate Dam last inspected?

Hargate Dam was last inspected on November 4, 2020. 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.