One person was swept away as swollen rivers submerged over 150 villages and affected more than one lakh people in Orissa where the water level of river Mahanadi was on the rise today, officials said.

Major rivers including Mahanadi, Brahmani, Kathajodi, Baitarani, Subarnarekha, Budhabalanga, Bansadhara and Jalaka were in spate following heavy downpour triggered by a low pressure.

A man, identified as Baisakhi Ojha, was washed away by the strong current of Baitarani river in Dasarathpur area of Jajpur district, they said.

Flood waters of the Baitarani river submerged over 40 villages in Jajpur and Dasarathpur blocks of Jajpur district affecting around 22,000 people, a senior district official said, adding relief and rescue operation was launched for the marooned villagers.

As the water level of the Mahanadi contiuned to rise menacingly, 36 of the 64 sluice gates were opened in Hirakud reservoir in Sambalpur district, official sources said, adding that water level crossed 626.31 feet as against the reservoir level of 630 feet.

Inflow of water at the reservoir touched 5,43,840 cusec while the outflow was 4,82,907 cusec, they said.

In Balasore district, around 135 villages were submerged by flood waters of Subarnarekha, Budhabalanga and Jalaka river affecting about one lakh people, special relief commissioner P K Mohapatra said.

In Bhadrak district, several villages were inundated as flood waters of the Baitarani submerged vast areas including 528 hectares of agriculture land in Dhamnagar and Bhandari Pokhari areas. Water level in Baitarani rose to 18.16 feet as against the danger mark of 17.83 feet at Akhuapada, he said.