Webster Lake Dam

CHANCE POND BROOK· Merrimack, New Hampshire· Built 1873· Concrete· 14 ft tall
High Hazard Recreation State Government

Key Takeaway

Webster Lake Dam is classified as high hazard in New Hampshire. It was completed in 1873 and is 153 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 14 ft (taller than 42.1% in NH)
Dam Length133 ft
Dam TypeConcrete
Max Storage2.7K acre-ft
Normal Storage1.1K acre-ft
Surface Area612 acres
Drainage Area19 sq mi
Max Discharge5,557 cfs
Year Completed1873 (153 years old)
Year Modified2003
NID IDNH00410

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: September 12, 2022
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 Webster Lake Dam?

Webster Lake 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 Webster Lake Dam?

Webster 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 Webster Lake Dam built?

Webster Lake Dam was completed in 1873, making it 153 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 Webster Lake Dam?

Webster 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 Webster Lake Dam?

Webster Lake Dam has a dam height of 14 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 Webster Lake Dam last inspected?

Webster Lake Dam was last inspected on September 12, 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.