The Orissa government on Friday night requisitioned the assistance of the Indian Army as a serious flood in the Mahanadi river system threatened the thickly populated coastal plains.

Two deaths were reported in Cuttack district where Banki and Athagarh sub-divisions were already affected as Sapua and Kantia rivers played havoc, official sources said.

While one person was swept away in the swirling waters of Sapua in Bentapada village on Friday, another marooned villager died of snakebite at Ichhapur on Thursday, the sources said.

Four columns of army have already left Ranchi and were expected to arrive in Bhubaneswar by Saturday morning. They would be deployed for rescue and relief operations.

Services of naval divers had also been requisitioned.

The administration was on a high alert in the districts of Cuttack, Kendrapara, Jajpur, Jagatsinghpur and Puri, which are expected to be affected by the floods.

Heavy rains in three western districts triggered off the floods.

In Cuttack district an estimated 20,000 people in 11 villages of eight panchayats of Banki block had been evacuated to safer places. The Banki subdivision had been cut-off from outer world as seven feet of water was flowing on the Cuttack-Banki Road for a stretch of about six km.

A 90 feet breach on the left embankment of Sapua at Gobardhanpur village under Baramba block inundated large areas.

Villagers in Rajnagar, Tarding, Dorad, Bentapada, Joranda, Samasarpur, Kunthakata and Ichhapur had been marooned by the floodwaters, sources said.

About 12 lakh cusecs of the floodwaters had been fed to the Mahanadi by its biggest tributary, Tel, downstream of the Hirakud dam, while the situation turned complicated following heavy inflow into the vast reservoir near Sambalpur.

The water level in the Hirakud reservoir had touched 629 feet, just one foot less than the maximum water level, forcing the authorities to open 24 of its 64 sluices, Chief Secretary Pratip Kumar Mohanty said.

Fourteen more gates would be opened to let out more water into the river.

The reservoir was receiving an increased inflow of 6.55 lakh cusecs and the discharge had been pegged at 3.12 lakh cusecs this evening, he said.

Orissa on Friday evening requisitioned the army's assistance as the state geared up to face the wrath of the Mahanadi river system following heavy rains in its catchment areas.

As much as 14 lakh cusecs of water rushing down the Mahanadi is expected to reach the delta head at Naraj sometime in the night even as inflows into the Hirakud dam reservoir on the river near Sambalpur city are rising sharply.

Tel, a major tributary of Mahanadi downstream of Hirakud, has contributed 12 lakh cusecs following heavy rains in the districts of Kalahandi, Balangir and Sonepur in the past two days. Any big discharge from the Hirakud dam now would complicate matters downstream, senior officials said.