Onway Lake Dam

TR LAMPREY RIVER· Rockingham, New Hampshire· Built 1915· Concrete· 9 ft tall
Low Hazard Recreation Private

Key Takeaway

Onway Lake Dam is classified as low hazard in New Hampshire. It was completed in 1915 and is 111 years old. Its primary use is recreation.

Physical Details

Dam Height 9 ft (taller than 10.9% in NH)
Dam Length65 ft
Dam TypeConcrete
Max Storage2.6K acre-ft
Normal Storage2.1K acre-ft
Surface Area194 acres
Drainage Area9 sq mi
Year Completed1915 (111 years old)
NID IDNH00438

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 15, 2018
State Regulated: Yes
Regulatory Agency: NH DES

Ownership

J AND D REALTY TRUST

Private

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Pawtuckaway Lake Dollof Dam

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Pawtuckaway Lake/Gove Dike

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Deep Hole Pond Dam

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Scribner Road Dam

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Pingree Sawmill Dam

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Socha Dam

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Frequently Asked Questions

What is the hazard classification of Onway Lake Dam?

Onway Lake 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 Onway Lake Dam?

Onway Lake Dam is owned by J AND D REALTY TRUST (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Onway Lake Dam built?

Onway Lake Dam was completed in 1915, making it 111 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 Onway Lake Dam?

Onway Lake 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 Onway Lake Dam?

Onway Lake Dam has a dam height of 9 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 Onway Lake Dam last inspected?

Onway Lake Dam was last inspected on November 15, 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.