Over 155 kilometres of roads and highways have been damaged by the second wave of floods in Sylhet, Sunamganj and Moulvibazar districts.

According to the Roads and Highways Department (RHD), at least 25 roads and highways under these three districts were affected due to heavy rains and subsequent flash floods during the second half of last month.

Of the 155.41 km of damaged roads, 6.90 km are national highways, 45.44 km are regional highways, and 103.07 km are district roads.

The first wave of flooding in Sylhet occurred on 29 May, submerging six border upazilas due to heavy rainfall and upstream mountain runoff. The water level began to recede after 8 June.

However, flooding resumed on 16 June, affecting all 13 upazilas in the district, including Sylhet city, and impacting over 10 lakh people. The second wave of floodwater began to recede on 25 June.

Heavy rainfall and runoff caused another round of flooding from 1 July.

RHD officials said many roads and highways were submerged in parts of Sylhet, Sunamganj and Moulvibazar districts during the second wave of floods triggered by heavy rains and the onrush of water from upstream.

Some of the affected roads were partially washed out due to heavy flooding, while road embankments collapsed in many places.

At the same time, potholes emerged on many roads owing to the damage to the pavement surface.

Also, bridges and culverts were damaged in many places.

Md Zikrul Hassan, superintending engineer of RHD's maintenance circle, told the Daily Sun, "We cannot repair roads during a flood. The extent of damage is determined after the floodwater recedes from the affected roads. Already, one of our monitoring teams has visited the affected roads of the Sylhet region. I hope that the flood-damaged roads will be repaired under the next repair programme."

Meanwhile, the monthly forecast of the Bangladesh Meteorological Department says there is a possibility of more-than-expected heavy rainfall in the country in July, causing short- to medium-term flooding in the northern, northeastern, northwestern, north-central, and central parts of the country.

Experts blame poor planning ahead of road construction and ignoring regional climate states as the main reasons for floods causing so much damage to roads.

Some 472.21 km of roads and highways under the RHD were also damaged due to floods across the country last year.

Transport expert BUET Professor Md Hadiuzzaman told the Daily Sun that the construction of bitumen roads in flood-prone areas or low-lying districts is in no way compatible because bitumen gets damaged due to heavy rain or flooding.

He suggests constructing concrete roads in low-lying areas where floodwater could inundate roads, as water flow cannot damage a concrete road. Also, a concrete road becomes passable soon after the floodwater recedes, he stated.