The Bog Brook Reservoir is a 379-acre (153 ha) reservoir in the Croton Watershed in southern New York State. It is located in the town of Southeast, New York in Putnam County, and is approximately 38 miles (over 60 kilometers) north of New York City, to which it supplies water. It was formed by the damming of Bog Brook, a small tributary of the East Branch of the Croton River, which is in turn a tributary of the Croton River.