The Ib River originates in the hills near Pandrapat, in the Raigarh district of Chhattisgarh at an elevation of about 762 m. Maina, Sapal and Bheden are the important tributaries of the river. The sub-basin lies between the north latitudes of 21°30' and 23°08' and east longitudes of 83°30' and 84°45'.
The total length of the river is about 251 km and it falls now into the Hirakud Reservoir on its left. The total drainage area of the river is 12,447 km2. It is rain-fed river and hence nearly 80% of runoff occurs during the monsoon months of June to October.