 The Hatfield Waste Drain crosses under the North Engine Drain before the junction, and then becomes the north channel.The centre channel is formed by the North Engine Drain and the River Torne, while the south channel carries the waters of the South Engine Drain and the Folly Drain.Bull Hassocks pumping station was designed to handle water from the South Idle drains, but prior to 1970 also had to handle water from the Folly Drain.