The Mahanadi is one of the longest rivers in India and drains a large part of peninsular India. The fertile plains of the river valley are home to intensive rice cultivation. The Mahanadi and Brahmani rivers together form a large delta at the confluence with the Bay of Bengal. The city of Cuttack lies at the head of this delta. This delta houses one of the largest mangrove forests in peninsular India.The Baisipalli Sanctuary and the Satkosia Gorge Sanctuary south of the river (part of the Mahanadi Wildlife Division) houses a variety of birds and animals. The Mahanadi river is one of the best known fresh water turtle habitats in the country as its deep water pools, sand banks and mid river islands provide an ideal home to the animals.

The water quality of the river has deteriorated over the years due to the presence of large number of urban settlements and industries that discharge the waste water into the river without any treatment.The Hirakund dam is built on the river. It is the largest earth dam in the country.