Mahanadi River Delta encompasses an area of 0.1 km, which counts nearly 4.3% of the total geographical area of the country. The basin lies in the Indian states of Chhattisgarh (covering 75,136 km²), Orissa (covering 65,580 km²), Bihar (covering 635 km²) and Maharashtra (238 km²) for a total of 141589-km² area. The main tributaries of the Mahanadi River are Seonth, the Hasdeo, the Mand, the Jonk, the Ib, the Ong, and the Tel. The geography of Mahanadi River is credited for irrigating a fertile valley where crops of rice, oilseed, and sugarcane are grown.
Geographically, the delta of River Mahanadi can be divided into four zones, namely, the Northern Plateau, the Eastern Ghats, the Coastal Plain and the Erosional Plains of Central Table Land. The first two zones are the hilly regions, while the coastal plain is the central interior region of the delta, which is traversed by the river and its tributaries. The main soil types found in the basin are red and yellow soils, mixed red and black soils, laterite soils and deltaic soils.
India is setting up a third Antarctic base in Larsemann Hills that, 120 million years ago, was contiguous with India`s eastern coast. One of the main aims of this base is to investigate how India broke away from Antarctica and Larsmann Hills could reveal vestiges of the Mahanadi River, which flowed there about 130 million years ago when the continent was included in the Gondwanaland.
An average annual surface water potential of 66.9 km³ has been recorded in the Mahanadi river basin. Out of this, 50.0 km³ is utilizable water and cultivable area in the basin is around 80,000 km², which is 4% of the total cultivable area of the country.
Present use of Mahanadi River`s surface water in the basin is 17.0 km³. Actual storage capacity in the basin has increased considerably since independence. From just about 0.8 km³ in the pre-plan period, the total live storage capacity of the completed projects has increased to about 8.5 km³. In addition, a significant storage quantity of more than 5.4 km³ would be created on conclusion of projects that are still under construction. Thereafter, additional storage of more than 11.0 km³ would be available on implementation of projects under planning. The hydropower prospective of the basin has been planned as 627 MW at 60% capacity factor.
