Dredging Karnaphuli: Work hindered by plastic waste

The cutter suction dredger (CSD), which was brought from China in February last year to dredge the river, was returned in August that year as the contractor wants to use the latest grab dredger to excavate. 

A CSD is equipped with a rotating cutter head for cutting and fragmenting harder soils and rock while a grab dredger picks up seabed material with a clamshell bucket, which hangs from an onboard crane.

A recent survey conducted by the researchers at Bangladesh University of Engineering and Technology revealed that the riverbed has a layer of polythene and plastic waste stretching from 2 to 7 metres, said sources at the Chattogram Port Authority (CPA).

The CPA had initiated "Sadarghat to Bakaliar Char Dredging" project at a cost of Tk 258 crore in May 2018 to restore navigability of the Karnaphuli.

The four-year-project is supposed to be completed in 2022, said CPA sources.

In October 2018, excavation began with three small dredgers. But dredging was hampered due to the polythene layer, said Commander M Arifur Rahman, chief hydrographer at the CPA and director of the project.

The contractor had been facing problems from the beginning as the cutter blades were getting jammed.

"It slowed down the progress as we could dredge for only an hour a day whereas we were supposed to dredge for 18 hours a day," Arifur said.

"At present, the dredging is being conducted with a local grab dredger," he said, adding that around 18 percent work of the project have been completed so far."

Arifur said polythene bags dumped in 37 canals of the city eventually end up in Karnaphuli river.

So, the dredging would be of no use in the long run if dumping of polythene in the canals cannot be stopped, he added.

This correspondent visited Chaktai Khal found it to be blocked by polythene and plastic wastes. The layer of waste was so thick that anyone could mistake it for a landfill.

The Chaktai Khal which begins from Bahaddarhat in the city and flows along Chawkbazar and Bakalia areas to merge with the Karnaphuli in Chaktai area.

Residents in these areas suffer waterlogging during the rainy season every year as the canal cannot deal with the rush of water as it remains almost filled with polythene and plastic waste, said the residents.

Raju Barua, a resident of Ghasia Para, said he did not see the Chattogram City Corporation (CCC) cleaning the canal in the last six months.

"The canal should be cleaned once a month but the CCC officials do not even clean it twice a year," he said.

Contacted, Mohammad Shamsuddauha, chief executive officer at the CCC, said the layer of polythene did not accumulate in the last two or five years.

Asked why they do not clean the canals regularly, he said they do not have the logistic support and manpower.

"In many areas, banks of canals are grabbed. So, our vehicles cannot go there," he said.

The CCC CEO said as the Chattogram Development Authority (CDA) has undertaken a project to reduce waterlogging in the city, it is their responsibility to clean up the canal.

Although the CDA has initiated the project, Bangladesh Army has been implementing it.

Contacted, Lt Col Md Shah Ali, project director, said last year they cleaned most of the canals, including Chaktai canal, but those have been filled with polythene again.

"Cleaning up the canals is not the ultimate solution, people will have to be conscious," he said.