Lake Welch Dam
Lake Welch Dam is a concrete dam located in Rockland County, New York, built in 1937. It carries a High hazard potential classification and has a poor condition assessment.
About Lake Welch Dam
The primary purpose of Lake Welch Dam is recreation. The dam creates a reservoir used for recreational activities such as fishing, boating, and swimming. The dam is owned by Nysoprhp - Palisades Interstate Park Commission (state). It impounds the Minisceongo Creek near Willow Grove.
The dam stands 32 feet tall and stretches 788 feet across, creates a reservoir covering 182 acres, has a maximum storage capacity of 4,750 acre-feet, and collects water from a drainage area of 2 square miles. Completed in 1937, the structure is well-established, with more than 75 years of service.
This dam carries a high hazard potential classification, which means that a failure or uncontrolled release of water would likely cause loss of human life. This classification reflects the consequences of failure, not the likelihood — it indicates that people live or work in the area downstream. 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 05/07/2025.
At 32 feet, this dam is taller than 76% of dams nationwide.
Living Downstream
If you live or work downstream of this dam, consider taking these steps: learn your local evacuation routes, check whether your county emergency management office has a dam failure inundation map, and sign up for local emergency alerts. The New York dam safety program can provide more specific information about emergency planning for this structure.
Search for dams near your address to see all dams in your area with hazard classifications and safety data.
Location
| State | New York |
| County | Rockland |
| Nearest City | Willow Grove |
| River/Stream | Minisceongo Creek |
| Coordinates | 41.22948, -74.07161 |
Physical Characteristics
| Dam Type | Concrete |
| NID Height | 32 ft |
| Dam Height | 32 ft |
| Dam Length | 788 ft |
| Year Completed | 1937 (89 years old) |
Storage & Hydraulics
| NID Storage | 4,750 acre-ft |
| Max Storage | 4,750 acre-ft |
| Normal Storage | 3,072 acre-ft |
| Surface Area | 182 acres |
| Drainage Area | 2 sq mi |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Recreation |
| Owner | NYSOPRHP - PALISADES INTERSTATE PARK COMMISSION |
| Owner Type | State |
| Hazard Classification | High |
| Condition Assessment | Poor |
| Last Inspection | 05/07/2025 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | NY00283 |
| Federal ID | NY00283 |
| More Info | State Dam Safety Program |