According to official sources, two rivers in Rayagada district - Bansadhara and Nagabali - were in spate and the situation was likely to aggravate in the next few hours as rains were still on as this report was filed.
Free kitchens have been set up in the affected areas and schools have been closed in Kalyansinghpur block of the badly-hit Rayagada district.
The district has within the last 24 hours received almost 190mm of rainfall and around 80 percent areas of Kalyansinghpur remain submerged in deep water.
Notably, road communication between Rayagada and Bhawanipatna has been disrupted as flood water is now flowing on the major road in the area which is now completely cut-off.
The Rayagada district administration started serving cooked food to those sheltered in schools.
The IAF was called since it is not possible to rescue people by boat.
The Odisha government on Sunday asked the help of the army and the air force personnel to rescue the marooned persons and urged the Centre to provide four helicopters for the rescue operations. Kalahandi District Collector Anjan Kumar Manik said one person from Thuamul Rampur block has died.
The floods have resulted in the inundation of NH 16 at Komarada in Vizianagaram district, and railway bridge No. 588 between Singapuram Road-Therubali railway stations.
The flash floods, followed by an alarming rise in the water levels in the Nagavalli and the Kalyani rivers inundated vast areas, causing extensive damage to bridges and snapping road and railway connectivity.
An East Coast Railway (ECoR) official said that three trains were cancelled, two short terminated and one train diverted as flood water was still running on certain train lines in the southern region of Odisha.
Bhubaneswar Meteorological Department Director Sarat Sahu said a low pressure area had formed over northwest Bay of Bengal off north Odisha.