||River Mahanadi: It is the major river of Odisha and the sixth largest river in India. It originates from the sihawa hills of theBastar Plateau in Raipur district of [Chhattishgarh]. It is about 857 km Long (494 km in Odisha) and its catchment area spreads over 141,600 km2. (65,580 km².) in Odisha. The river carries on an average about 92,600 million m of water.