Tarrytown Waterworks Dam
Tarrytown Waterworks Dam is an earth dam located in Westchester County, New York, built in 1897. It carries a High hazard potential classification and has a poor condition assessment.
About Tarrytown Waterworks Dam
The primary purpose of Tarrytown Waterworks Dam is water supply. The dam stores water for municipal, industrial, or agricultural use, helping ensure a reliable supply for the surrounding area. The dam is owned by Village Of Tarrytown (local government). It impounds the Tr-saw Mill River near Elmsford.
The dam stands 18 feet tall and stretches 315 feet across, creates a reservoir covering 81 acres, has a maximum storage capacity of 1,100 acre-feet, and collects water from a drainage area of 1 square miles. Completed in 1897, 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 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 01/02/2025.
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 | Westchester |
| Nearest City | Elmsford |
| River/Stream | Tr-saw Mill River |
| Coordinates | 41.08292, -73.83197 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 18 ft |
| Dam Height | 18 ft |
| Dam Length | 315 ft |
| Year Completed | 1897 (129 years old) |
Storage & Hydraulics
| NID Storage | 1,100 acre-ft |
| Max Storage | 1,100 acre-ft |
| Normal Storage | 890 acre-ft |
| Surface Area | 81 acres |
| Drainage Area | 1 sq mi |
| Max Discharge | 590 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Water Supply |
| Owner | VILLAGE OF TARRYTOWN |
| Owner Type | Local Government |
| Hazard Classification | High |
| Condition Assessment | Poor |
| Last Inspection | 01/02/2025 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | NY00054 |
| Federal ID | NY00054 |
| More Info | State Dam Safety Program |