Every year, the pattern seems strangely familiar.
Summer arrives, temperatures soar, roads radiate heat and cities become increasingly uncomfortable. Then the monsoon arrives. Within hours of intense rainfall, the same roads can turn into streams, underpasses fill with water and traffic comes to a standstill.
At first glance, extreme heat and urban flooding appear to be two completely different problems. One is caused by high temperatures and the other by excessive rainfall.
But there is a deeper connection.
The way Indian cities are being built is turning ordinary weather hazards into urban disasters.
Recent flooding across parts of Indian cities has once again shown how quickly intense rainfall can overwhelm roads, drains and public infrastructure. The problem is not simply that cities receive too much rain. It is also about what happens to that rain after it reaches the ground.
Rain is not the only culprit
Imagine a city before extensive urbanisation.
Rain falls on soil, grass, trees, ponds and open land. A significant portion of the water slowly seeps into the ground, while natural streams, wetlands and drainage channels carry the excess away.
Now replace much of that landscape with:
• Concrete buildings
• Asphalt roads
• Parking areas
• Footpaths
• Flyovers
• Paved courtyards
The city’s ability to absorb water falls dramatically.
Concrete and asphalt are largely impermeable. Instead of infiltrating into the soil, rainwater quickly becomes surface runoff and moves towards drains and low-lying areas.
Research examining urban flooding across Indian cities has identified intense rainfall, increased impervious surfaces, urban expansion, encroachment and inadequate drainage as major factors behind recurring urban flooding.
So when a very intense spell of rain arrives, the question is not merely “How much rain fell?”
It is also:
“Where can all that water go?”
We are building over the city’s natural drainage system
Many cities historically developed around lakes, ponds, wetlands, streams and floodplains.
These were not merely scenic features. They were part of the city’s natural water-management system.
Wetlands can temporarily store excess water. Lakes can act as reservoirs. Natural drainage channels provide pathways for runoff.
When these spaces are filled, narrowed or built over, the city loses its natural protection.
A systematic review of urban flooding in India notes that wetlands, marshes and lakes can provide flood protection, while urban development and encroachment have reduced these natural buffers in several cities.
This creates a dangerous situation.
We remove the sponge and then wonder why the city floods.
Drains cannot solve everything
Storm-water drains are essential, but they are not a substitute for sensible urban planning.
Many drainage networks were designed for the rainfall patterns and urban density of an earlier period. Cities, however, have expanded rapidly, while extreme rainfall events can deliver enormous quantities of water within a short period.
If the amount of runoff exceeds the capacity of the drainage network, water has nowhere to go.
The problem becomes even worse when drains are clogged with solid waste or poorly maintained. Government disaster-management guidance has also identified inadequate drainage, encroachment on natural drainage and indiscriminate disposal of waste as important contributors to urban flooding.
This explains why even a relatively short spell of intense rain can sometimes produce hours of waterlogging.
Then comes the other half of the problem: extreme heat
The same city that floods during the monsoon can become a furnace during summer.
Why?
Because concrete, asphalt and buildings do not behave like soil, vegetation and water bodies.
They absorb solar energy during the day and release stored heat gradually. Trees that could provide shade and cool their surroundings through evapotranspiration are often insufficient in densely built neighbourhoods.
This produces what scientists call the Urban Heat Island effect.
Urban areas can become significantly warmer than surrounding rural areas because of the concentration of buildings, roads and other heat-absorbing surfaces. The World Bank has estimated that temperatures in Indian city centres can be around 3 to 4°C higher than surrounding areas in some circumstances.
And the problem does not end when the sun goes down.
Concrete and asphalt continue releasing the heat they absorbed during the day. This can make nights uncomfortable and reduce the body’s opportunity to recover from daytime heat.
The loss of trees makes the problem worse
Trees are not simply decorative additions to an urban landscape.
They provide shade, reduce surface temperatures and contribute to cooling through evapotranspiration. Green spaces also allow rainwater to infiltrate into the ground.
When trees and open spaces disappear, cities lose both natural cooling systems and natural drainage systems.
This is why flooding and overheating can actually have the same underlying cause:
the loss of natural landscapes beneath expanding urbanisation.
Climate change is adding another layer of risk
Urbanisation is only one part of the story.
Climate change is altering the background conditions in which cities operate. Periods of extreme heat are becoming a greater concern, while intense rainfall events can place extraordinary pressure on urban drainage systems.
That does not mean climate change alone causes every flood or heatwave.
Rather, it can make an existing urban vulnerability much more dangerous.
A city with adequate drainage, open spaces, wetlands, trees and resilient infrastructure has a greater ability to absorb a weather shock.
A city covered in concrete, with inadequate drainage and disappearing natural water systems, has much less room for error.
The real problem is urban planning
This is perhaps the most important lesson.
A heatwave, cloudburst or intense rainfall event is a hazard.
It becomes a disaster when people and infrastructure are exposed to it without sufficient capacity to cope.
That means disaster management cannot begin only after water enters people’s homes or temperatures become dangerous.
It has to begin much earlier, with the way cities are planned.
Urban planning, drainage, housing, transport, waste management, water bodies, green spaces and disaster management cannot operate as completely separate subjects.
They are connected.
What can Indian cities do?
1. Protect wetlands and water bodies
Lakes, ponds and wetlands should be treated as urban infrastructure rather than vacant land waiting for construction.
2. Restore natural drainage channels
Natural streams and drainage paths need to be mapped, protected and restored wherever possible.
3. Increase permeable surfaces
Cities can encourage permeable pavements, rain gardens, green spaces and other measures that allow water to infiltrate rather than immediately becoming runoff.
4. Design drainage for present and future rainfall
Storm-water infrastructure must account for changing rainfall intensity and expanding urban populations rather than relying solely on historical assumptions.
5. Increase urban tree cover
Tree planting should focus on survival, maintenance and strategic placement, particularly around pedestrian routes, residential areas and heat-vulnerable neighbourhoods.
6. Make development climate-sensitive
Construction in flood-prone areas, natural drainage channels and vulnerable floodplains should be carefully regulated.
7. Integrate different civic agencies
Drainage, roads, sewage, waste management and land-use planning often involve different authorities. Better coordination is essential because water does not respect administrative boundaries.
From “fighting floods” to building resilient cities
For decades, the dominant approach has often been reactive.
It rains, roads flood, pumps are deployed, drains are cleaned and temporary relief measures are announced.
Then the water disappears.
Until the next monsoon.
The same cycle repeats with heatwaves. Temperatures rise, advisories are issued and people are told to stay indoors. But the underlying urban design that traps heat remains unchanged.
India’s cities need to move from emergency response to risk reduction.
The goal should not be to create cities that can somehow survive every extreme weather event.
The goal should be to create cities where extreme weather is less likely to become a disaster in the first place.
The city of the future must work with nature
A resilient Indian city cannot be built entirely out of concrete.
It needs trees to cool it, wetlands to absorb water, lakes to store it, open spaces to let the ground breathe and drainage networks to safely carry away what nature provides in excess.
The irony is striking.
The same natural features that can help keep a city cool in summer can also help keep it from flooding during the monsoon.
Perhaps, therefore, the solution to India’s urban climate problem is not simply more infrastructure.
It is better infrastructure combined with better urban planning and respect for the natural systems that existed before the city did.
Because when the rain comes, a city should not have to choose between becoming a lake and becoming a furnace.
It should be designed to remain a city.
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