Swan Lake Dam

WEST BRANCH MONGAUP RIVER· Sullivan, New York· Built 1894· Stone· 31 ft tall
Significant Hazard Recreation Private

Key Takeaway

Swan Lake Dam is classified as significant hazard in New York. It was completed in 1894 and is 132 years old. Its primary use is recreation. Significant hazard means failure could cause economic or environmental damage. Learn more.

Physical Details

Dam Height 31 ft (taller than 80.7% in NY)
Dam Length135 ft
Dam TypeStone
Max Storage3.8K acre-ft
Normal Storage2.2K acre-ft
Surface Area327 acres
Drainage Area15 sq mi
Max Discharge950 cfs
Year Completed1894 (132 years old)
NID IDNY00333

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: December 6, 2018
State Regulated: Yes
Regulatory Agency: NYS DEC

Ownership

SWAN LAKE COMMONS LLC

Private

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Swan Lake Dam?

Swan 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 Swan Lake Dam?

Swan Lake Dam is owned by SWAN LAKE COMMONS LLC (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Swan Lake Dam built?

Swan Lake Dam was completed in 1894, making it 132 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 Swan Lake Dam?

Swan 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 Swan Lake Dam?

Swan Lake Dam has a dam height of 31 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 Swan Lake Dam last inspected?

Swan Lake Dam was last inspected on December 6, 2018. 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.