Trinity Dam
Trinity Dam is an earth dam located in Westchester County, New York, built in 1966. It carries a High hazard potential classification and has a satisfactory condition assessment.
About Trinity Dam
The primary purpose of Trinity 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 Aquarion Water Company Of Ct (private). It impounds the Tr-mill River near Sarles Corners.
The dam stands 50 feet tall and stretches 300 feet across, creates a reservoir covering 110 acres, has a maximum storage capacity of 3,700 acre-feet, and collects water from a drainage area of 0 square miles. Completed in 1966, the structure is well into its service life at over 50 years 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 02/05/2025.
At 50 feet, this dam is taller than 93% 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 | Westchester |
| Nearest City | Sarles Corners |
| River/Stream | Tr-mill River |
| Coordinates | 41.21402, -73.55454 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 50 ft |
| Dam Height | 50 ft |
| Dam Length | 300 ft |
| Year Completed | 1966 (60 years old) |
Storage & Hydraulics
| NID Storage | 3,700 acre-ft |
| Max Storage | 3,700 acre-ft |
| Normal Storage | 2,550 acre-ft |
| Surface Area | 110 acres |
| Drainage Area | 0 sq mi |
| Max Discharge | 1,600 cfs |
| Spillway Type | Controlled |
Ownership & Safety
| Purpose | Water Supply |
| Owner | AQUARION WATER COMPANY OF CT |
| Owner Type | Private |
| Hazard Classification | High |
| Condition Assessment | Satisfactory |
| Last Inspection | 02/05/2025 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | NY00129 |
| Federal ID | NY00129 |
| More Info | State Dam Safety Program |