Mahanadi River Delta in India is a basin of deposit that washes away a large landmass of the Indian subcontinent into the Bay of Bengal. The alluvial valley is quite wide and relatively flat with a twisting river channel that alters its course. The Mahanadi River flows at a slow pace for around 900 km and has an estimated drainage area of 132,100 square km. The river deposits more silt than almost any other river in the Indian subcontinent. The area of the drainage basin is around 141,464 km². The interior coastal plain has a relatively low height. The average altitude of the drainage basin is 426 m, with a maximum of 877 m and a minimum of 193 m.

The Population density in Mahanadi River Delta
The upper part of the Mahanadi delta plain is heavily populated. The population density exceeds 36 people per km², although moving toward the coast the population density falls. Rainfall comes principally from the summer monsoon, during the months from June to September. The average annual rainfall in the basin is 1,463 mm. Rainfall is recorded to be exceptionally low during the rest of the year, rarely exceeding 30 mm per month.

The Mahanadi River begins in southeastern Madhya Pradesh as a small stream draining the eastern part of the Chhattisgarh Plain, later it enters Orissa State below Baloda Bazaar and crosses the eastern Ghats to enter the Plains of Orissa near Cuttack and finally empty into the Bay of Bengal through a series of channels after traveling almost 900 km. The Hirakud Dam has a 55-km long lake or reservoir alongside. The famous city of Puri is located at one of the distributary mouths.

Drainage density is extremely dense in this area. The area of the drainage basin is approximately 141,464 sq km. The interior coastal plain has a relatively low elevation and relief is extremely low. The average elevation of the drainage basin is around 426 m, with a maximum of 877 m and a minimum of 193 m.

The upper part of the deltaic plain is densely populated with a density more than 36 people per sq. km, although the frontal part of the delta is much less so. Rainfall is mostly during the summer and monsoon months and an average annual rainfall in the basin is 1,463 mm. The rest of the year, rainfall is exceptionally low.