Unplanned urbanisation erases 21,000 Ctg water bodies, worsens flooding: Experts

Chattogram has lost nearly 21,000 ponds and other water bodies over the past three decades, severely weakening its natural drainage system and turning waterlogging into a chronic urban crisis, experts said today (27 July).

Speaking at a discussion organised by the Bangladesh Environmental Lawyers Association (Bela), they blamed unplanned urbanisation, indiscriminate filling of water bodies and low-lying land, blocked natural drainage channels, poor waste management and weak implementation of existing plans.

Presenting the keynote paper, Muhammad Rashidul Hasan, professor of Urban and Regional Planning at Chittagong University of Engineering and Technology (Cuet), said Chattogram City Corporation once had around 24,500 water bodies, but only about 3,500 remain. In some wards, 80-90% have disappeared.

Infographics: TBS

"The loss of water bodies is one of the main reasons behind Chattogram's worsening waterlogging. Areas that once retained rainwater have now been replaced by concrete structures," he said. 

Plans exist, implementation lags

Prof Rashidul said the city's built-up area expanded 46-fold between 1993 and 2003, 17-fold between 2003 and 2013, and 36-fold between 2013 and 2023, consuming low-lying land, farmland, hills, playgrounds and water bodies. Major infrastructure and housing projects accelerated urban expansion but largely overlooked drainage and environmental sustainability.

Despite having at least 16 masterplans, policies and laws – including the Drainage Masterplan, Detailed Area Plan (DAP), Waterlogging Mitigation Project, Wasa plans and national water and land-use policies – the city has failed to implement them effectively.

"The problem is not a lack of plans; it is a lack of implementation," he said, stressing that restoring canals, water bodies and natural drainage is as important as building drains.

Waste, tides deepen the crisis

Chattogram generates about 3,000 tonnes of waste daily, but the city corporation manages only 2,000 tonnes. The remaining waste clogs canals and drains, while hill runoff, silted canals and reduced navigability of the Karnaphuli River further restrict water flow.

Describing the situation as a "system failure", Prof Rashidul said both institutional shortcomings and poor public waste disposal practices had contributed to the crisis.

Engineer Delwar Majumder, president of Transparency International Bangladesh's (TIB) Citizens' Awareness Committee in Chattogram, said the city's coastal geography compounds flooding. High tides reach 5.35 metres above sea level, while many low-lying areas lie only 2-2.5 metres above sea level, leaving rainwater trapped during heavy downpours.

He said the 1995 Drainage Masterplan was never implemented in a coordinated manner, as agencies including the City Corporation, Port Authority, Railway and Wasa pursued separate projects. He also questioned whether the Tk32.8 crore allocated for a new masterplan would be sufficient for long-term metropolitan planning.

Prof Rashidul urged authorities to restore canals, protect water bodies, harvest rainwater and expand green spaces, while offering tax incentives to encourage conservation of ponds and wetlands.

Speakers said preserving water bodies, canals, wetlands and green spaces must become central to development planning if Chattogram is to become a sustainable, climate-resilient city.

Among those present were Romana Akter, assistant director of the Department of Environment in Chattogram Metropolitan; Engineer Ahmad Moinuddin, executive engineer of the Chattogram Development Authority; Kaiser Ahmed, assistant engineer at the Bangladesh Water Development Board; and Monira Parveen Ruba, divisional coordinator of Bela in Chattogram.