Why Does Mumbai Get Clogged In The Rain?
Why Does Mumbai Get Clogged In The Rain? In addition to Instagram stories romanticizing the weather, for many parts of Mumbai, rain is a source of deep trouble – literally – as waterlogging disrupts life and sometimes leads to horror stories of death and destruction .
But what is it about Mumbai that it can’t handle the non-stop rain almost every year during the monsoon season? Here are five main factors that play a role:
Topography – what does it stand on?
The coastal city has many low-lying areas and some quite high. Parts of the city were built on reclaimed land between seven islands, hence the saucer-shaped areas.
This means that water – especially when there is heavy rain – flows naturally to these areas. It also flows, but only after the rain stops. These areas include Sion, Andheri subway, Milan subway, Khar subway, which remain submerged for few hours after heavy rains.
As rains lashed the city and its suburbs on Monday night, Sion and Andheri were already flooded. It was on high alert for even more rain.
Tidal fluctuations of the sea
Mumbai’s storm water drainage system drains into the sea. During high tide – when the sea level rises – drains are blocked by gates to prevent sea water from flowing back into the city’s drainage system.
Worse, the high tide coupled with heavy rain means that drainage has to be done using pumps. After the tide subsides, the drainage system starts functioning again. But it can take up to six hours.
Percolation – water in the ground
In most cities around the world, at least half of the water ends up in the ground. In Mumbai, 90 per cent of storm water is diverted through dedicated drains. This puts additional pressure on the drainage system.
Weather patterns – heavy and unusual
Drainage systems are designed for evenly spread monsoons. But, in recent years, Mumbai has received some very heavy rains, followed by dry weather and then very heavy rains.
On days of unusually heavy rainfall, even drains with increased capacity may not actually recover.
Encroachment – blocked by people
Mumbai has witnessed massive encroachment along major drains, making clearing solid waste and silt a challenging task. Despite the cleaning of pre-monsoon drains, drains often get clogged during monsoon.
This means that naturally there would have been more waterlogging.