Every heavy downpour now follows a familiar pattern in Dhaka. Roads disappear beneath murky water, vehicles break down, commuters spend hours stranded in traffic, and businesses, schools, and hospitals struggle to function.
As an active monsoon continues to bring heavy to very heavy rain across Bangladesh, Dhaka has once again found itself submerged, exposing how the city has gradually lost the natural waterways that once carried stormwater into surrounding rivers.
Heavy rain on Sunday inundated hundreds of roads across areas under both Dhaka North and Dhaka South City Corporations (DNCC and DSCC), with water remaining in many neighborhoods until yesterday as fresh rainfall continued.
The Bangladesh Meteorological Department has forecast heavy rainfall for several more days, raising fears that waterlogging could worsen unless drainage systems improve.
Urban planners say climate change is increasing the intensity of rainfall, but Dhaka's chronic flooding is primarily the result of decades of canal encroachment, shrinking wetlands, inadequate drainage infrastructure, and poor coordination among government agencies.
For generations, Dhaka relied on an interconnected network of canals, natural drains, and wetlands that carried rainwater into the Buriganga, Turag, Balu, and Shitalakkhya rivers.
Today, much of that network has disappeared.
Many canals have been encroached upon or filled in for development, while others have become disconnected from the drainage network. As the city expanded rapidly, wetlands and open spaces that once absorbed rainwater gave way to roads and concrete.
The result is a city where even an hour of intense rainfall can leave major roads underwater.
Residents say the problem has become an annual crisis despite repeated promises of permanent solutions.
The government handed responsibility for Dhaka's 26 major canals to the Dhaka Water Supply and Sewerage Authority (Wasa) in 1988 to improve drainage management.
After years of criticism over deteriorating canal conditions, the canals were transferred to the Dhaka North and Dhaka South city corporations in 2021.
Five years later, however, urban planners say the city's drainage performance has changed little.
Many canals remain clogged with waste, narrowed by illegal encroachment, or disconnected from surrounding drains, preventing stormwater from flowing efficiently toward nearby rivers.
"The city has lost its blue network," urban planner and architect Iqbal Habib said earlier.
"Rainwater naturally flows from higher ground through canals into rivers. That system no longer functions in Dhaka. Unless we restore the canal network, waterlogging will continue regardless of how many drains are cleaned."
According to DSCC, its 109.24-square-kilometer jurisdiction, home to around 15 million people, depends on only four major stormwater outlets.
Water from Malibagh, Shantinagar, Motijheel, and Paltan is discharged through the TT Para Pump Station.
Old Dhaka drains through Dholai Khal into the Buriganga River, while Dhanmondi, Green Road, and Panthapath discharge through Hatirjheel and the Rampura Pump Station.
Parts of Jatrabari and the DND area depend on the Shimrail Pump Station before water reaches the Shitalakkhya River.
Engineers say these outlets are insufficient to handle large volumes of rain falling within a short period.
DSCC Administrator Bir Muktijoddha Mohammad Abdus Salam acknowledged the challenge.
"We are trying to remove accumulated water as quickly as possible, but the city has very limited routes for stormwater to reach the rivers," he said.
"We are working to create additional outlets. Significant improvements may take time, but we expect better capacity in the coming years."
Meteorological data show Dhaka receives an annual average of around 2,018 millimeters of rainfall.
While the annual total has remained relatively stable over the decades, rainfall events have become increasingly concentrated and intense.
Records show rainfall exceeding 250 millimeters in a single day occurred only three times between 1953 and 2000. The same threshold was reached three times between 2001 and 2024.
Dhaka's highest recorded daily rainfall remains 341 millimeters, measured on September 14, 2004.
Experts say the existing drainage infrastructure was designed for a different rainfall pattern and is increasingly unable to cope with today's high-intensity downpours.
DSCC has identified 29 major waterlogging hotspots, including Dhanmondi, Green Road, New Market, Iskaton, Moghbazar, Malibagh, Khilgaon, Motijheel, Paltan, Fakirapool, Kamalapur, Shapla Chattar, and Sayedabad.
Sunday's rainfall, however, inundated areas well beyond those identified hotspots.
In Dhaka North, roads in Mirpur, Kazipara, Shewrapara, Kalshi, Agargaon, Mohakhali, Banani, Badda, Bhatara, Nikunja, Khilkhet, Uttara, and Abdullahpur also remained underwater for hours.
DNCC officials said emergency teams continued clearing drains, manholes, and canals throughout the rainfall period.
In a statement issued on Sunday, DNCC Administrator Shafiqul Islam Khan Milton said the corporation is implementing long-term initiatives to restore canals, improve drainage infrastructure, and modernize stormwater management.
Urban planner Sk Md Mehedi Ahsan said Dhaka's waterlogging crisis cannot be solved through emergency responses alone.
Instead, experts recommend restoring canals and wetlands, protecting natural water-retention areas, constructing additional drainage outlets and retention ponds, implementing an integrated drainage master plan, and improving coordination among Rajuk, Wasa, the two city corporations, and other relevant agencies.
Without reconnecting the city's drainage system to its rivers, they warn, Dhaka will continue to flood after every major downpour.
As climate change increases the frequency of extreme rainfall events, the cost of delaying those reforms will only continue to grow.