Big Brook Bog Dam

BIG BROOK· Coos, New Hampshire· Built 1946· Earth· 11 ft tall
Significant Hazard Recreation State Government

Key Takeaway

Big Brook Bog Dam is classified as significant hazard in New Hampshire. It was completed in 1946 and is 80 years old. Its primary use is recreation. Significant hazard means failure could cause economic or environmental damage. Learn more.

Physical Details

Dam Height 11 ft (taller than 23.8% in NH)
Dam Length370 ft
Dam TypeEarth
Max Storage250 acre-ft
Normal Storage107 acre-ft
Surface Area36 acres
Drainage Area3 sq mi
Max Discharge991 cfs
Year Completed1946 (80 years old)
Year Modified1971
NID IDNH00457

Safety Information

Significant Hazard

No probable loss of human life, but can cause economic loss, environmental damage, or disruption of lifeline facilities.

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

Emergency Action Plan: Yes
Last Inspection: September 15, 2020
State Regulated: Yes
Regulatory Agency: NH DES

Ownership

NH FISH AND GAME DEPARTMENT

State Government

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Big Brook Bog Dam?

Big Brook Bog Dam is classified as Significant Hazard. No probable loss of human life, but can cause economic loss, environmental damage, or disruption of lifeline facilities. This classification refers to the potential downstream consequences of a failure, not the dam's current structural condition.

Who owns and operates Big Brook Bog Dam?

Big Brook Bog Dam is owned by NH FISH AND GAME DEPARTMENT (State Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Big Brook Bog Dam built?

Big Brook Bog Dam was completed in 1946, making it 80 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 Big Brook Bog Dam?

Big Brook Bog 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 Big Brook Bog Dam?

Big Brook Bog Dam has a dam height of 11 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 Big Brook Bog Dam last inspected?

Big Brook Bog Dam was last inspected on September 15, 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.