A few hours of heavy monsoon rain is now enough to bring large parts of Dhaka to a standstill. Roads in Uttara, Mirpur, Dhanmondi, Badda, Mohammadpur, Banasree and New Bazar frequently go under knee- to waist-deep water, turning routine rainfall into a citywide disruption.
Urban planners say this was not always the case. Just a few decades ago, Dhaka was surrounded by extensive floodplains, canals, marshes and low-lying wetlands that acted as natural reservoirs during the monsoon. Those landscapes absorbed excess rainwater before gradually releasing it into the Buriganga, Turag, Balu and Shitalakkhya rivers.
A Dhaka Tribune investigation found that much of that natural drainage system has been filled, fragmented or converted into housing and infrastructure over the last four to five decades.
According to World Bank estimates, nearly 15,000 hectares of permanent wetlands and floodplains in and around Dhaka have disappeared beneath concrete since the 1980s. Researchers say the city has lost 75% to 90% of its natural flood-retention capacity, leaving even moderate rainfall with fewer places to go.
Dhaka in the 1960s: A city of rivers, canals and wetlands
Earlier, in the 1960s, Dhaka had approximately 13,500 hectares of low-lying flood-retention areas. The city was encircled by the Buriganga, Turag, Balu and Shitalakkhya rivers, while an intricate network of roughly 175 canals, beels and water bodies crisscrossed the urban landscape.
Rainwater did not accumulate rapidly on streets. Instead, it spread across floodplains and gradually drained through canals into surrounding rivers.
Urban planners describe that period as the era of “floodplain Dhaka”—a city that functioned in close ecological relationship with its rivers and seasonal inundation zones.
1980: Shahjalal Airport stood amid open floodplains
Historical satellite imagery, old topographic maps and planning documents show that when Hazrat Shahjalal International Airport began operations around 1980, its northern, northwestern and northeastern surroundings were largely uninhabited floodplains.
Areas that are now known as Uttara Sectors 14, 17 and 18, Diyabari, Byljurri, Faydabad and the Kaladia canal corridor were then seasonal wetlands connected to the Turag River.
Those lowlands served as major water-retention zones for northern Dhaka. During the monsoon, floodwater spread across the area and was stored naturally before draining toward the river system.
How the map changed
The turning point came after the 1990s. RAJUK’s 1995 metropolitan development plan identified the corridor from Diyabari to the Turag River as protected floodplain and wetland. However, subsequent revisions of the Detailed Area Plan (DAP) reclassified large portions of those areas for residential use.
Urban governance experts say this marked the beginning of state-led wetland conversion.
Sk Mehadi Hasan, Vice President of the Bangladesh Institute of Planners (BIP), said the conversion of floodplains into residential land has weakened Dhaka’s natural drainage system and increased urban disaster risk.
He warned that changing land-use classifications through planning revisions without preserving ecological functions creates long-term costs that are ultimately borne by city residents.
Once floodplains were incorporated into residential land-use maps, large-scale filling and plot development accelerated across northern and eastern Dhaka.
How floodplains became housing projects
The investigation found that RAJUK itself initiated housing development on reclaimed lowlands by constructing roads, filling water bodies and preparing plots for urban expansion.
Field observations in Uttara’s peripheral sectors revealed:
- Boundary walls built directly within water bodies
- Wetlands filled with sandbags and earth
- Canals cut and subdivided into plots
- Roads constructed across former beels
- Remaining water bodies fragmented and sold as developable land
Local residents alleged that government projects first altered the character of these areas, after which private developers and influential landholders expanded real estate activities rapidly.
The cost of losing 15,000 hectares
World Bank analysis suggests that roughly one-fifth of water retention areas within the RAJUK jurisdiction have been filled by housing projects and urban development.
The consequences are increasingly visible:
- Frequent urban waterlogging after moderate rainfall
- Reduced drainage efficiency
- Declining groundwater recharge
- Rising urban temperatures
- Loss of aquatic and wetland biodiversity
Researchers say rainwater that was once absorbed by floodplains is now trapped within roads, underpasses and densely built residential blocks.
Canals have fallen to less than half
The number of functional rivers and canals within the Dhaka metropolitan area has dropped to well below half of its historical level.
Many canals have been:
- Encroached upon
- Filled
- Narrowed
- Disconnected from the drainage network
As connections between the city and the Buriganga, Turag, Balu and Shitalakkhya have weakened, stormwater can no longer exit the urban basin efficiently.
Uttara: From seasonal wetland to concrete metropolis
Uttara has become one of the clearest examples of this transformation.
What was largely seasonal floodplain in the 1980s now contains:
- High-rise residential towers
- Commercial complexes
- Metro rail infrastructure
- Extensive road networks
- Plot-based housing developments
Hydrologists say the area’s natural water-storage capacity has declined dramatically, contributing to persistent waterlogging in Diyabari and surrounding neighborhoods during heavy rainfall.
Urban planner Sk Md Mehedi Ahsan again said rapid housing expansion in Uttara has not been matched by adequate drainage, mobility and emergency-access planning. He noted that transport corridors, metro infrastructure and real-estate projects have expanded simultaneously, but the underlying floodplain hydrology was not integrated into the urban design process.
New aviation safety risks around the airport
The growth of dense settlements around Shahjalal Airport has also created aviation safety concerns.
Aircraft approach and depart at low altitude directly above populated neighborhoods. Experts warn that any mechanical failure during takeoff or landing could result in catastrophic ground casualties.
Following the Milestone tragedy, authorities recommended stricter controls on building heights, removal of hazardous structures near flight paths and enforcement of the airport’s final approach safety zone.
Yet implementation has remained slow. RAJUK records show that 630 buildings were identified between 2015 and 2025 as requiring regulatory action, but most cases have not been fully resolved.
Professor Dr Md Hadiuzzaman, transport expert at the Bangladesh University of Engineering and Technology (BUET), said airport-adjacent urbanization must be evaluated not only from a land-use perspective but also from a public safety and transport resilience perspective.
He said high-density settlements near critical aviation corridors increase the potential human impact of any emergency event during takeoff or landing and therefore require stricter coordinated planning among RAJUK, CAAB and transport authorities.
RAJUK chairman acknowledges planning failure
RAJUK Chairman Engr Md Reazul Islam has acknowledged that the conflict between airport operations and surrounding urbanization is the result of long-term planning deficiencies.
He said low-lying lands were converted into residential areas through legal loopholes and changes in land-use regulations.
Urban experts view the statement as a rare public admission that policy decisions contributed directly to the erosion of Dhaka’s floodplain system.
“Wrong design and engineering failure”
Environmental activist Sharif Jamil described the filling of wetlands for housing projects as “Wrong design and engineering failure.”
“When concrete is placed where water is supposed to remain, the city eventually retaliates through waterlogging, heat stress and infrastructure failure,” he told Dhaka Tribune.
He further added when we occupy spaces of monsoon water, it comes to our homes and streets as an obvious outcome.
He argued that modern urban planning worldwide seeks to preserve natural water bodies within townships, whereas Dhaka has often pursued development by eliminating them.
Who benefited?
Interviews with officials, planners and environmental researchers identified several groups that have profited from floodplain conversion:
- Sand suppliers
- Land developers
- Construction contractors
- Housing companies
- Influential encroachment networks
These actors benefited from the rising value of reclaimed land as Dhaka expanded northward and eastward.
Climate change is intensifying the risk
Dhaka’s vulnerability is now being amplified by climate change.
The city is experiencing:
- More intense short-duration rainfall
- Longer heatwaves
- Altered river flow patterns
- A stronger urban heat-island effect
Experts say the destruction of floodplains reduces the city’s ability to adapt to these emerging climate stresses.
The World Bank has repeatedly warned that restoring wetlands and flood-retention areas is essential for reducing Dhaka’s long-term flood and waterlogging risk.
The unanswered question
The central question emerging from the investigation is this: How did land officially recorded as floodplain gradually become residential plots, commercial assets and real-estate commodities?
The answer appears to lie at the intersection of:
- Planning amendments
- Land reclassification
- Weak approval processes
- Political influence
- Powerful economic interests in the housing sector
Dhaka today is not merely a waterlogged city.
It is a metropolis built over the graves of its floodplains—a city that once coexisted with rivers and seasonal wetlands, but has steadily replaced them with concrete.
And the price of that transformation is now being paid by millions of residents with every monsoon, every flooded street and every neighborhood that disappears under water after a few hours of rain.
