The Utkal Plain is part of the Eastern Coastal Plain of India. It is a coastal plain in the Odisha state of eastern India. It includes the delta of the Mahanadi River, Brahmani River, Baitarani River. The most prominent physiographic feature of this plain is the Chilka Lake. It is the biggest lake in the country and its area varies between 780 km2 in winter to 1,144 km2 in the monsoon months.