Willow Pond Dam

NISSEQUOGUE RIVER· Suffolk, New York· Built 1915· Earth· 12 ft tall
Significant Hazard Recreation State Government

Key Takeaway

Willow Pond Dam is classified as significant hazard in New York. It was completed in 1915 and is 111 years old. Its primary use is recreation. Significant hazard means failure could cause economic or environmental damage. Learn more.

Physical Details

Dam Height 12 ft (taller than 23.2% in NY)
Dam Length300 ft
Dam TypeEarth
Max Storage32 acre-ft
Normal Storage31 acre-ft
Surface Area8 acres
Drainage Area6 sq mi
Year Completed1915 (111 years old)
NID IDNY14090

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: November 8, 2018
State Regulated: Yes
Regulatory Agency: NYS DEC

Ownership

NYS OFFICE OF PARKS, RECREATION & HISTORIC PRESERVATION- LONG ISLAND REGION

State Government

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Willow Pond Dam?

Willow Pond 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 Willow Pond Dam?

Willow Pond Dam is owned by NYS OFFICE OF PARKS, RECREATION & HISTORIC PRESERVATION- LONG ISLAND REGION (State Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Willow Pond Dam built?

Willow Pond Dam was completed in 1915, making it 111 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 Willow Pond Dam?

Willow Pond 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 Willow Pond Dam?

Willow Pond Dam has a dam height of 12 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 Willow Pond Dam last inspected?

Willow Pond Dam was last inspected on November 8, 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.