Around 58,000 people in 16 unions of the district have been stranded as the water level of Mahananda and Punorbhaba rivers rose, causing immense suffering to the locals.
Roads, houses and cropland were inundated as the rivers burst their banks.
"Some 11,300 hectares of cropland have been flooded," said Manjurul Huda, deputy-director of the Department of Agriculture Extension.
Sources at Chapainawabganj Water Development Board said Mahananda was flowing 14cm below the red level while Padma was 33cm and Punarbhaba 36cm below the danger level on Friday.
WDB Executive Engineer Syed Shahidul Alam said the water level will decline in two to three days if there is no heavy rain.
Hasanuzzman, an official of District Relief and Rehabilitation centre, said 100 metric tons of rice has been allocated for the flood-affected people.