History & Culture · Hudson Valley
North Castle Is Split by Kensico Reservoir
Kensico Reservoir splits North Castle into distinct hamlet geographies, giving the town its unusual shape.
Published June 23, 2026 · Last verified June 23, 2026
North Castle is a Westchester town split by water and hamlets. The Kensico Reservoir separates North Castle into northern and southern parts, with North White Plains, Armonk, and the eastern Banksville area forming distinct geographies. That helps explain why the town can feel suburban, village-like, and rural on the same drive.
The historical society adds an older layer: the Kensico Dam flooded the valley where the village of Kensico and surrounding farms once stood. Armonk is now the seat of town government, while North White Plains is the more urban section. North Castle’s identity is not one center; it is a reservoir-separated set of places.
That is the picture to carry around town. Armonk, North White Plains, Banksville, the reservoir edge, and the lost Kensico valley all explain a piece of the map. North Castle makes more sense when you expect a town of parts, not a single downtown with everything arranged around it.
It also explains why directions can sound oddly specific here. Someone may say Armonk, Banksville, North White Plains, or the Kensico side of town and mean very different daily landscapes. The reservoir is not just scenery; it changes how the pieces of North Castle relate.