Byram Lake Reservoir Dam
Byram Lake Reservoir Dam is an earth dam located in Westchester County, New York. It carries a High hazard potential classification and has a poor condition assessment.
About Byram Lake Reservoir Dam
The primary purpose of Byram Lake Reservoir 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 Mt Kisco (local government). It impounds the Byram River near Armonk.
The dam stands 27 feet tall and stretches 185 feet across, creates a reservoir covering 164 acres, has a maximum storage capacity of 3,610 acre-feet, and collects water from a drainage area of 1 square miles.
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 02/05/2025.
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 | Armonk |
| River/Stream | Byram River |
| Coordinates | 41.15528, -73.69306 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 27 ft |
| Dam Height | 27 ft |
| Dam Length | 185 ft |
Storage & Hydraulics
| NID Storage | 3,610 acre-ft |
| Max Storage | 3,610 acre-ft |
| Normal Storage | 2,909 acre-ft |
| Surface Area | 164 acres |
| Drainage Area | 1 sq mi |
| Max Discharge | 273 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Water Supply |
| Owner | VILLAGE OF MT KISCO |
| Owner Type | Local Government |
| Hazard Classification | High |
| Condition Assessment | Poor |
| Last Inspection | 02/05/2025 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | NY01175 |
| Federal ID | NY01175 |
| More Info | State Dam Safety Program |