Willow Pond Dam
Willow Pond Dam is an earth dam located in Suffolk County, New York, built in 1915. It carries a Significant hazard potential classification and has a poor condition assessment.
About Willow Pond Dam
The primary purpose of Willow Pond Dam is recreation. The dam creates a reservoir used for recreational activities such as fishing, boating, and swimming. The dam is owned by Nys Office Of Parks, Recreation & Historic Preservation- Long Island Region (state). It impounds the Nissequogue River near Smithtown.
The dam stands 12 feet tall and stretches 300 feet across, creates a reservoir covering 8 acres, has a maximum storage capacity of 32 acre-feet, and collects water from a drainage area of 6 square miles. Completed in 1915, the structure is over a century old.
This dam has a significant hazard potential classification, meaning that a failure could cause significant economic damage — flooding roads, bridges, or property downstream — but is not expected to result in loss of life. Its condition is rated poor, meaning the dam has recognized safety deficiencies that require remediation to address risks. An emergency action plan is in place for this dam. The most recent inspection on record was 12/13/2022.
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Location
| State | New York |
| County | Suffolk |
| Nearest City | Smithtown |
| River/Stream | Nissequogue River |
| Coordinates | 40.85000, -73.22806 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 12 ft |
| Dam Height | 12 ft |
| Dam Length | 300 ft |
| Year Completed | 1915 (111 years old) |
Storage & Hydraulics
| NID Storage | 32 acre-ft |
| Max Storage | 32 acre-ft |
| Normal Storage | 31 acre-ft |
| Surface Area | 8 acres |
| Drainage Area | 6 sq mi |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Recreation |
| Owner | NYS OFFICE OF PARKS, RECREATION & HISTORIC PRESERVATION- LONG ISLAND REGION |
| Owner Type | State |
| Hazard Classification | Significant |
| Condition Assessment | Poor |
| Last Inspection | 12/13/2022 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | NY14090 |
| Federal ID | NY14090 |
| More Info | State Dam Safety Program |