The entire mountain is in the Hudson River watershed, with runoff from the north taking a circuitous route to it via Schoharie Creek and the Mohawk River. On the southeast corner, the route is much more direct, as water follows Stony Clove Creek to Esopus Creek and thence to the Hudson. The cirque on the southwest gives rise to a Schoharie tributary, the West Kill, also fed by Hunter Brook. Regardless of the stream, all of Hunter is part of New York City's watershed, as the Esopus is impounded in Ashokan Reservoir and the Schoharie in the similarly named reservoir downstream.