Shannon Lake Dam

SHANNON BROOK· Carroll, New Hampshire· Built 1930· Earth· 20 ft tall
Significant Hazard Recreation Private

Key Takeaway

Shannon Lake Dam is classified as significant hazard in New Hampshire. It was completed in 1930 and is 96 years old. Its primary use is recreation. Significant hazard means failure could cause economic or environmental damage. Learn more.

Physical Details

Dam Height 20 ft (taller than 70.9% in NH)
Dam Length300 ft
Dam TypeEarth
Max Storage21 acre-ft
Normal Storage15 acre-ft
Surface Area4 acres
Drainage Area2 sq mi
Max Discharge3,195 cfs
Year Completed1930 (96 years old)
Year Modified1969
NID IDNH00562

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: April 21, 2022
State Regulated: Yes
Regulatory Agency: NH DES

Ownership

CASTLE PRESERVATION SOCIETY

Private

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Shannon Lake Dam?

Shannon Lake 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 Shannon Lake Dam?

Shannon Lake Dam is owned by CASTLE PRESERVATION SOCIETY (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Shannon Lake Dam built?

Shannon Lake Dam was completed in 1930, making it 96 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 Shannon Lake Dam?

Shannon 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 Shannon Lake Dam?

Shannon Lake Dam has a dam height of 20 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 Shannon Lake Dam last inspected?

Shannon Lake Dam was last inspected on April 21, 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.