Crystal Lake Dam

CRYSTAL LAKE BROOK· Grafton, New Hampshire· Built 1910· Earth· 22 ft tall
Significant Hazard Recreation State Government

Key Takeaway

Crystal Lake Dam is classified as significant hazard in New Hampshire. It was completed in 1910 and is 116 years old. Its primary use is recreation. Significant hazard means failure could cause economic or environmental damage. Learn more.

Physical Details

Dam Height 22 ft (taller than 76.5% in NH)
Dam Length170 ft
Dam TypeEarth
Max Storage4.6K acre-ft
Normal Storage2.1K acre-ft
Surface Area378 acres
Drainage Area13 sq mi
Max Discharge2,404 cfs
Year Completed1910 (116 years old)
Year Modified1984
NID IDNH00269

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: October 21, 2020
State Regulated: Yes
Regulatory Agency: NH DES

Ownership

NH DES WATER DIVISION

State Government

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Crystal Lake Dam?

Crystal 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 Crystal Lake Dam?

Crystal Lake 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 Crystal Lake Dam built?

Crystal Lake Dam was completed in 1910, making it 116 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 Crystal Lake Dam?

Crystal 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 Crystal Lake Dam?

Crystal Lake Dam has a dam height of 22 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 Crystal Lake Dam last inspected?

Crystal Lake Dam was last inspected on October 21, 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.