Ctg city canals filling up again despite projects

The Chattogram city canals are once again filling up with polythene, plastic, household waste, construction materials, hill soil, sand and silt.

As a result, the depth and water-holding capacity of the canals are declining rapidly, creating a renewed risk of waterlogging during heavy rainfall.

The authorities concerned claim that waterlogging has been reduced significantly through various measures, including canal re-excavation, expansion, eviction of illegal encroachments, construction of sluice gates and improvement of the drainage system.

The city’s major canals were re-excavated and renovated under the ‘Canal Re-excavation, Expansion, Renovation and Development Project to Reduce Waterlogging in Chattogram City,’ approved by ECNEC in 2017.

Initially estimated at Tk 5,616 crore, the project cost was later revised to Tk 9,526 crore.

The project period has also been extended several times and is now in its final stage.

Under the project, extensive excavation work has been completed in more than 36 canals and sub-canals across the city. Lakhs of cubic metres of soil have been removed from canal beds.

The project, implemented under Army supervision, removed various types of waste, including discarded furniture, broken beds and mattresses.

In addition to excavation, many canals have been widened and roads have been constructed along their banks.

However, silt, soil and different types of waste have already accumulated again in many canals, reducing their depth alarmingly.

Vegetation has begun to grow on the deposited soil in several canals, although these waterways were cleaned only a year ago.

Experts say the primary cause of canal filling is not engineering-related but social.

The widespread tendency to use canals as waste disposal sites and open dustbins is destroying the waterways.

Household, market, hotel, shop and small industrial waste is being dumped directly into canals in different parts of the city.

Large quantities of plastic, polythene, bottles, clothing, wood, food waste and other garbage are deposited daily.

As water flow slows, these materials settle at the bottom, accelerating sedimentation.

Construction activities also contribute significantly to the problem. Soil, sand, brick debris and cement residues from piling work often enter canals directly, reducing their depth.

In addition, illegal hill cutting in various parts of the city causes large amounts of soil to wash into canals during the monsoon.

Canals such as Chaktai Khal, Mahesh Khal, Mirza Khal and Naya Khal have experienced significant siltation due to soil washed down from nearby hills.

Urban planners say many residents still view canals as dumping grounds rather than essential components of the city’s natural drainage system.

Consequently, despite spending thousands of crores of taka, the benefits of canal excavation are not being sustained.

They note that the primary function of the canals is to carry rainwater quickly to the Karnaphuli River and the Bay of Bengal. When canal depth decreases, water flow slows considerably, increasing the risk of waterlogging during heavy rainfall.

Reduced water flow also creates favourable conditions for mosquitoes and waterborne diseases, disrupting urban life in various ways.

Engineers warn that a one-metre reduction in canal depth can reduce water-holding capacity several times over.

Urban experts believe that canal excavation alone will not solve the problem unless public attitudes change.

They have emphasised the need for a permanent canal management structure.

Urban planners have recommended annual pre-monsoon dredging, strict penalties for dumping waste into canals, improved waste management in markets and residential areas, installation of awareness signboards along canal banks, formation of canal protection committees involving local residents, and stronger monitoring to prevent hill cutting and soil dumping.

They point out that Chattogram, a city surrounded by hills, rivers and the sea, has no natural reason to suffer from waterlogging. The city’s canals are the lifelines of its natural drainage system.

Although projects worth thousands of crores of taka have given the canals a new lease of life, experts warn that the gains are now under threat due to poor public awareness, unplanned waste management and a lack of regular maintenance.