Each monsoon, Dhaka relives the same nightmare. During heavy rains, roads become shallow canals, traffic gets stuck, businesses lose precious hours and commuters have to wade through water that is frequently teeming with sewage and waste. The familiar answer is that there are too few drains, they're clogged, too narrow or not well maintained. That's not such a wrong explanation. However, it is no longer adequate to talk about the city as the object of action.
The city of Dhaka certainly requires efficient drains, working pumps, clean catch pits, canals with a sufficient carrying capacity. But the city can't continue to build more drains and lose the ponds and wetlands, flood-flow areas, open soil and vegetation that used to soak up, store and slowly release rain. The fundamental issue is that Dhaka is being increasingly designed to run off rather than to provide more and more areas where it can be absorbed.
It has long been foretold in research. Abdullah et al. (2022) discussed the impacts of urban green and blue spaces loss in Bangladesh and its impact on ecosystem services. Research on Dhaka also has associated encroachment on water bodies with an increased flood risk and water stagnation in the city, and unplanned urbanisation and inadequate drainage. All this research indicates that waterlogging is not just a problem of pipe and pump failures. It's also a symptom of the growth of the city that has been permitted.
The hydrology is a fairly straightforward system. A field, pond, wetland or open soil can store or absorb rainfall and serve as a natural barrier in heavy rains. Concrete roads, paved compounds, rooftops and buildings can not do that. In the city of Dhaka, as urbanisation is getting higher and higher, surface runoff is becoming more rapid and heavier compared to the amount of water that it takes to reach the water network. Any drainage system, even if well designed and maintained, can become overwhelmed if the greater urban area absorbs water at a rate greater than it can retain.
Dhaka requires more than just a drainage strategy, this is. What it requires is a sincere stormwater plan to manage rainwater as a part of the urban fabric, not just a pipe.
In recent years, urban flood management has shifted to the concept of managing water where it is generated. Areas such as parks, ponds, permeable pavements, rain gardens, vegetated roadside channels, wetlands, green roofs and temporary detention basins can regulate, store and absorb runoff from the site before it reaches conventional drains. This is often referred to as the 'sponge effect' -- a city absorbing water in times of storm, retaining it temporarily and then gradually releasing it later.
The concept is especially applicable to Dhaka where a lot of its natural moistures are either lost or degraded. Some of it will need to be done through careful planning and not just as individual engineering schemes. An individual park with a temporary reservoir, a housing development with a portion of its infrastructure constructed out of permeable materials, or a parking lot with a portion of its surface area created to be pervious may not appear to be much when considered on its own. In a large city, however, such actions can minimize the volume of water going into the public drains all at one time.
Singapore provides an example of how it can work on the ground. It is the approach taken by its national water agency, PUB, in flood management, which is known as the Source-Pathway-Receptor approach. Precautions are made at the source to minimise the run-on, along the path to facilitate the flow of water, and at vulnerable sites to minimise the flood exposure. For new or redevelopment projects with a size and extent equal to or greater than 0.2 hectares, there must be on-site detention facilities installed to help reduce peak stormwater flows and runoff to public drains.
Dhaka doesn't need to be as exacting as Singapore! It has different density, institutions, finances and enforcement power. However, the essence of the idea is pertinent. Impermeable surfaces, where such surfaces can be created on the site of a large commercial complex, housing project or institutional development, and rainwater is exported onto public roads and drains should not be allowed. Increased runoff from development must be shared with the development in managing some of that runoff.
It also applies to the "sponge cities" of China. They are connected with traditional drainage, wetlands, green spaces, water storage spaces and permeable urban surfaces. The intent is not to "take the place of" engineered drainage, but to supplement it. The key lessons learned from these foreign experiences are that grey infrastructure and blue-green infrastructure should be linked as parts of an integrated urban water system in Dhaka.
However, the problem of waterlogging in Dhaka can't be solved based on engineering. Water has no respect for administrative boundaries and piecemeal efforts will result in piecemeal outcomes. If a connecting canal downstream is also blocked, it is a minor relief to clear a roadside drain. It is important to keep in mind that if retention areas continue to be filled and built next to the canal, there is little use for the canal. Plastic, construction and household waste can easily end up in the new drain if it's not effectively screened.
This is the reason of the costly and inefficient urban governance of Dhaka. The roads, drains, canals and water bodies, sewerage management, land development and solid waste management are not easily managed as separate system by a separate agency; agencies can not work effectively together without coordination. The four are all linked with the same urban water cycle.
Therefore, a change in policy should be made from activity measurement to outcomes measurement. Not just the money invested nor even the number of kilometres of drains built is a major determinant of the success of a waterlogging programme. The more pertinent question is: How many waterlogging hotspots have been eliminated from the chronically waterlogged areas? What happens to water levels after heavy rains in relation to the year before? How much is retained or how much is the retention capacity inhanced? Does a specific investment decrease the depth and length of floods in the geographic area to which it is intended to serve?
What is now crucial is to institutionalise such an outcome-focused approach. The World Bank approved $370 million for the Metro Dhaka Water Security and Resilience Program in February 2026. The programme integrates sanitation and solid-waste management with pollution reduction, and river and canal restoration and institutional reform. The World Bank estimates that nearly half of the formal jobs and one-third of Bangladesh's GDP are in greater Dhaka. This shows you the importance of the economic value involved.
But waterlogging is much more than a city problem. Late trips, disruptions to businesses, goods damage, office disruption, missed appointments and unavailable services all equate to economic losses. An inability to travel on major roads can cost a daily wage earner a day's wages, a small business a customer, and a business the cost of transport and logistics as well as perishable goods. Flooding also causes damage to roads, vehicles and property, depending on the extent, which costs more to households and government.
Now Dhaka needs to think about concrete and feasible changes. Current canals, ponds, wetlands and areas set aside for flood flows need a more robust level of legal and physical protection. Filling and building over a strategically important water body is difficult and costly to recreate.
New large developments must also demonstrate how they will control stormwater prior to final approval. Should be planned as common conditions and not just an option as environmental features, on site detention tanks, retention ponds, rain water collection or other appropriate methods.
If possible public parks and open spaces should be multi-purpose. They can be used as recreational areas when the weather is dry but serve as temporary storage for rainwater when storms hit. Where feasible permeable materials should also be used in footpaths, parking areas, courtyards and in selected public areas.
It's also essential to be transparent. Locate waterlogging hotspots and create a waterlogging schedule and agency responsibility map to be publicly available. The residents should be able to see how many times they have paid for something and whether it has had an impact on the situation; who is responsible if a given component of the system fails.
The management of solid waste should also be part of the flood management system and not is a municipal affair. A good engineered sewer system will not work if trash, construction materials, silt and plastic are blocking the inlets.
None of these imply that new drains are not needed in Dhaka. Some other drainage capacity will still be required in many neighbourhoods. Connecting regular maintenance is also needed for existing drains and connections with canals. Nor is it feasible for an ever-expanding megacity that is vulnerable to heavy monsoon rainfall to put a stop to all occurrences of temporary flooding.
The point is that is different. Dhaka has been dealing with the urban-water problem primarily by relying on drainage engineering for too long. However, waterlogging is also the consequence of cumulative land use decisions, declining water sources, over-paving, inadequate waste management, weak institutional capacity and fragmented institutions.
The waterlogging of Dhaka is not just about drainage but a reflection of unplanned urbanisation, reduction in water retaining spaces, poor drainage infrastructure and lack of coordination between urban agencies. With a changing climate and the rise in the intensity and frequency of heavy rains, conventional drainage methods will no longer be effective. For an integrated city wide water management policies and practices for Dhaka, which includes improvement of drainage facilities along with the restoration of canals, wetlands and natural water retention spaces.
The two city corporations and other concerned agencies should put in place a co-ordinated waterlogging management system incorporating institutional responsibilities. Before the monsoon, desilting and maintenance of drains, removal of illegal encroachments from canals and ensuring canal drainage outfalls are in working order should be given a high priority. New developments and roads should be designed to include sufficient water and ground retention.
Most importantly, Dhaka requires a long-term master plan, based on the new data on the hydrology, climate projections, and land use planning. Holding accountable through regular monitoring and transparent maintenance budgets and public reporting can help improve accountability. To achieve water-resilience, Dhaka needs not only larger drains, but a more intelligent planning process, reopening of waterways, and continued institutional coordination.
A true resilient city doesn't just question the rate that rainwater can be moved off a street. It also questions where that water can safely be stored, where it is absorbed and how it can be slowly released before it ultimately exits the city?
A few more drains will continue to be a part of Dhaka's response. They can't be the only solution. The first step towards staying afloat in a city is to learn to save room for water.
Major Md Rezaul Karim, AEC, MPhil is Programme Coordinator, Military Institute of Science and Technology (MIST), Mirpur Cantonment, Mirpur, Dhaka, Bangladesh.
