The Sankh River originates from Rajadera village of Gumla district. It is one of the three main rivers flowing through the district. After traveling through Gumla, it enters Simdega Districtand flows towards Orissa.
The river joins with the Brahmani River at Vedvyas near Rourkela. Mandira Dam is situated across the Sankh River, where boating facility is available. The length of the river is 240 Km. The 60 metres (200 ft) high Sadni Falls on the Sankh River at the edge of the Ranchi plateau is an example of scarp falls or knick line falls.