Murphy Dam

CONNECTICUT RIVER· Coos, New Hampshire· Built 1938· Earth· 106 ft tall

High Hazard Recreation State Government

Key Takeaway

Murphy Dam is classified as high hazard in New Hampshire. It was completed in 1938 and is 88 years old. Its primary use is recreation. 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	106 ft (taller than 99.1% in NH)
Dam Length	2,200 ft
Dam Type	Earth
Max Storage	132.0K acre-ft
Normal Storage	99.5K acre-ft

Surface Area	1,895 acres
Drainage Area	171 sq mi
Max Discharge	74,000 cfs
Year Completed	1938 (88 years old)
NID ID	NH00185

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: June 16, 2022

State Regulated: Yes

Regulatory Agency: NH DES

Ownership

NH DES WATER DIVISION

State Government

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Big Brook Bog Dam

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Frequently Asked Questions

What is the hazard classification of Murphy Dam?

Murphy Dam 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 Murphy Dam?

Murphy Dam is owned by NH DES WATER DIVISION (State Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Murphy Dam built?

Murphy Dam was completed in 1938, making it 88 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 Murphy Dam?

Murphy 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 Murphy Dam?

Murphy Dam has a dam height of 106 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 Murphy Dam last inspected?

Murphy Dam was last inspected on June 16, 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.