The catchment area of the Mahanadi river from its source to Hirakud dam excluding the catchment area of Sheonath, Jonk, Hasdeo, Mand and Ib is considered as Upper Mahanadi sub-basin measuring 21,652 km² catchment area which is 15.29% of the total Mahanadi basin. The sub-basin lies between north latitudes of 19°55' and 22°25' and east longitudes of 81°12' and 83°48'.