Mahanadi: The Great River

Mahanadi, the ‘Great River’, is a major rain-fed peninsular river in East Central India that flows through states of Chhattisgarh and Odisha and meets the water requirement for irrigation, domestic and industrial purposes in part of these states. The farthest headwater of the river lies on Sihawa hills. It splits into various channels at Naraj in Odisha, and emerge into an arcuate shaped delta. Progressive shifting of the Mahanadi river course and its coastline can be observed at different stages in the Mahanadi delta. The upstream part of the river is dominated by Proterozoic sedimentary rocks of Chhattisgarh basin while downstream part by silicate rocks of Eastern Ghat Mobile belt. A large number of minor to major projects have already commenced or are under construction and the canals that come out from these projects regulate the agriculture practices in the basin. This river is very vulnerable to climate change as the spatial distribution of regional rainfall pattern enhances the chance of flood in its downstream sub-catchments, while the upstream sub-catchments face threats of draught. The deteriorating water quality of the Mahanadi and its seasonal variability is also a cause of concern.