Explanation:

The North Koel rises on the Chhota Nagpur plateau and enters Latehar district , below Netarhat near Rud. After flowing nearly due west for about 32 kilometres (20 mi), it turns north at an almost complete right angle through a gorge at Kutku, and flows through the centre of the district until it falls into the Son a few miles north-west of Haidarnagar. From its source to its junction with the Son its length is about 260 kilometres (160 mi), and since it drains a catchment area of at least 9,100 square kilometres (3,500 sq mi), it naturally contributes a large supply of water to the Son during the rains; at other times the stream is not deep enough to enable cargo boats of even small dimensions to make their way up to Daltonganj. In many places the reaches of this river present scene of great beauty and sometimes even of grandeur, such as the rocky bed and rapids north of Hutar and the gorge at Kutku.