The embankments of the Mahanadi and its branches criss-crossing the coastal delta plains have a capacity to safely contain about 12 lakh cusecs of water, but if it is more then it could cause problems, he said.

While the Hirakud reservoir, built on the Mahanadi, was receiving 3,49,231 cusecs of water following heavy rains in Chhattisgarh, several sluices were opened to drain out 2,59,697 cusecs. Hirakud control room sources said more sluices are likely to be opened.

The flood was caused by heavy rains in the Mahanadi's lower catchment area below the Hirakud dam spread over the undivided Kalahandi and Balangir districts, the sources said. The water level at the Hirakud dam stood at 629.73 feet against its maximum capacity of 630 feet.The heavy precipitation in the lower catchment region flooded tributaries of the Mahanadi -- Udanti, Hati and Tel rivers.          

Reports said that flood waters entered Boudh, Sonepur and Athamallick and other towns located on edge of the Mahanadi river in western Orissa.

The chief secretary said that the water resources department has been directed to immediately focus on the vulnerable points on river embankments and attend them within six hours.

Meanwhile, the district administration in Kendrapara has evacuated about 5,000 people living in low-lying areas and shifted them to safer places.

Tripathy said that the panchayatiraj secretary has been asked to directly contact sarpanches and formulate strategies to meet the situation.

Schools in the four coastal districts likely to be affected by the deluge have been closed and would be used as temporary shelters for the people along with the large number of cyclone shelters built in the aftermath of the 1999 super cyclone.

Two MI-17 helicopters, now available with the government, were standing by to be used for relief and rescue operations, Tripathy said.