Why Dhaka keeps drowning every monsoon despite years of drainage projects
Experts say the real problem lies beneath the surface: lost canals, disappearing wetlands, poor planning and weak coordination among city agencies.
Highlights:
- 76mm of rain fell in six hours, the highest such rainfall in Dhaka this month
- Waterlogging crippled traffic across major roads and neighbourhoods
- Dhaka has lost 3,440 acres of flood zones and waterbodies since DAP-2010
- Waterbodies in central Dhaka have shrunk from 20.57% to 2.9% since 1995
- City corporations spent over Tk262 crore on drainage projects between 2021 and 2024
- Experts say restoring 15 canals could eliminate around 80% of the capital's waterlogging
Every monsoon, the same scenes return to Dhaka: roads disappear under water, vehicles break down, traffic grinds to a halt and thousands of commuters wade through knee-deep water just to reach work.
Today's (12 July) heavy rainfall once again exposed the capital's chronic drainage crisis, raising a familiar question: why does Dhaka still flood after every spell of rain despite years of investment and, more importantly, who can solve the problem?
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What caused today's flooding?
According to the Bangladesh Meteorological Department (BMD), an active monsoon combined with a low-pressure system over the Bay of Bengal triggered the intense rainfall.
The weather office said rainfall is likely to continue across much of the country for at least two more days before gradually easing around 14-15 July.
BMD Director Mominul Haque said the unusually intense rainfall over a short period also reflects the influence of El Niño-related climate variability, noting that similar weather patterns are affecting India, China and other South Asian countries.
Why does Dhaka flood so easily?
Urban planners say heavy rainfall alone is not the problem.
The capital's drainage network has gradually lost its ability to carry stormwater because canals have been encroached upon, wetlands filled, natural water retention areas destroyed and drainage channels blocked by waste and unplanned development.
The result is that even moderate rainfall now overwhelms the city's drainage capacity.
Billions spent, little improvement
The two Dhaka city corporations have invested more than Tk262 crore over the past four years to improve drainage, constructing more than 334 kilometres of drains and box culverts.
Yet residents continue to experience severe waterlogging after every major rainfall.
Experts argue that building more drains alone cannot solve the crisis unless the city's natural drainage system is restored.
Dhaka's disappearing waterbodies
A 2019 study by the Bangladesh Institute of Planners paints a worrying picture.
Since the previous Detailed Area Plan (DAP 2010), Dhaka has lost 3,440 acres of designated flood-flow zones, retention ponds and water bodies.
The decline is even more striking over the longer term.
In 1995, waterbodies covered 20.57% of central Dhaka. By 2023, they accounted for only 2.9%.
Green spaces have also shrunk dramatically, falling from 22% to 9% over the same period.
Urban planners say these natural spaces once absorbed rainwater that now has nowhere to go.
Can reopening canals solve the problem?
According to a 2024 study by the River and Delta Research Centre (RDRC), the answer is largely yes.
The study estimates that restoring just 15 encroached canals could reduce roughly 80% of the capital's recurring waterlogging.
Among the canals identified for restoration are Rupnagar Main Khal, Baunia Khal, Baishteki Khal, Sangbadik Colony Khal, Kalyanpur Khal, Ibrahimpur Khal, Panthapath Box Culvert Khal, Rayerbazar Khal, Jirani Khal, Rampura Khal, Dolai Khal, Kadamtali Khal and Manda Khal.
The research also identified nine major waterlogging hotspots stretching from Mirpur and Pallabi to Dhanmondi, Green Road, Rampura, Badda, Old Dhaka and Jurain.
Who is responsible?
Experts say responsibility is shared among multiple agencies.
Poor coordination between city corporations, water authorities, development agencies and utility providers often delays drainage projects and maintenance.
Illegal encroachment of canals, inadequate waste management, blocked drains, delayed infrastructure works and indiscriminate littering all contribute to the crisis.
Because drainage infrastructure is closely linked to roads, utilities and urban planning, specialists say fragmented governance has become one of the biggest obstacles to solving Dhaka's flooding problem.
What needs to change?
Urban planners say Dhaka needs a comprehensive, long-term drainage strategy instead of relying on emergency responses after every spell of heavy rain.
They recommend recovering encroached canals and wetlands, protecting the city's remaining flood retention areas, improving solid waste management to prevent drains from becoming clogged, introducing sustainable urban drainage systems, ensuring stronger coordination among all agencies responsible for drainage and urban development, and carrying out regular maintenance of existing drainage infrastructure.
Experts say unless these structural problems are addressed, Dhaka will continue to experience severe waterlogging every monsoon, regardless of how many new drains are built.
