Batavia Kill is a 21-mile-long (34 km) tributary of Schoharie Creek, that flows across the towns of Windham, Ashland and Prattsville in the U.S. state of New York. Its waters reach the Hudson River via Schoharie Creek and the Mohawk River. Since it drains into the Schoharie upstream of Schoharie Reservoir, it is part of the New York City water supply system. From the source to Maplecrest, Batavia Kill drains the northern slopes of the Blackhead Mountains, which include Thomas Cole Mountain, Black Dome, and Blackhead Mountain, the fourth-, third-, and fifth-highest peaks in the Catskills, respectively.