Willow Brook Dam
Willow Brook Dam is an earth dam located in Orange County, New York, built in 1924. It carries a High hazard potential classification and has a satisfactory condition assessment.
About Willow Brook Dam
The primary purpose of Willow Brook Dam is recreation. The dam creates a reservoir used for recreational activities such as fishing, boating, and swimming. The dam is owned by Orange And Rockland Utilities Inc (public utility). It impounds the Tr-merriewold Lake near Bull Mine.
The dam stands 20 feet tall and stretches 550 feet across, creates a reservoir covering 76 acres, has a maximum storage capacity of 995 acre-feet, and collects water from a drainage area of 1 square miles. Completed in 1924, the structure is over a century old.
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 satisfactory, indicating no existing or potential dam safety deficiencies are recognized. An emergency action plan is in place for this dam. The most recent inspection on record was 10/03/2023.
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 | Orange |
| Nearest City | Bull Mine |
| River/Stream | Tr-merriewold Lake |
| Coordinates | 41.35000, -74.19833 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 20 ft |
| Dam Height | 20 ft |
| Dam Length | 550 ft |
| Year Completed | 1924 (102 years old) |
Storage & Hydraulics
| NID Storage | 995 acre-ft |
| Max Storage | 995 acre-ft |
| Normal Storage | 585 acre-ft |
| Surface Area | 76 acres |
| Drainage Area | 1 sq mi |
| Max Discharge | 935 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Recreation |
| Owner | ORANGE AND ROCKLAND UTILITIES INC |
| Owner Type | Public Utility |
| Hazard Classification | High |
| Condition Assessment | Satisfactory |
| Last Inspection | 10/03/2023 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | NY00035 |
| Federal ID | NY00035 |
| More Info | State Dam Safety Program |