One of the fun activities which I miss as a grown-up is walking in the waterlogged streets of Kolkata. I will never forget those rainy days when I walked home after school hours through a drowned road.
I was not alone. My friends were also as ecstatic as me. We enjoyed ourselves to the fullest, much to the chagrin of our mothers when we went home. We were all completely drenched, especially from splashing water on each other with reckless abandon.
One day the magic was over.
The schoolboy grew up.
While in college, I experienced the difficulty waterlogging causes when I visited my friend’s home after a heavy shower. The roads were slightly waterlogged but his ground-floor home had water inside. How difficult is it to live in a home full of dirty water? How grueling is it to cook and eat in such a home?
I saw what sort of misery rains cause in a city.
Later in my life, I experienced waterlogging in many Indian cities.
The rainwater clearing system is poor in almost all of our cities. Is it because they were mostly built a long time back, during the British period?
Well, I thought so.
But it is not true.
Even newly-built cities like Gurgaon are not free of this menace.
There are many reasons for the problem.
Today, we will discuss why this is an unsolved issue in Kolkata.
Kolkata is no Different, All Indian Cities Face this Problem
There is no city in India that does not get waterlogged after a few hours of heavy rain. And if it rains continuously for a couple of days, a common occurrence in the monsoon season, low-lying areas are sure to get flooded. Even big cities face the inundation of widespread areas.
We have experienced exceptionally heavy rainfalls in a matter of hours, cloudbursts, and continuous rains for days in recent times. Added to them are cyclones which bring with them massive rainfalls.
Our cities’ rainwater clearance systems are incapable of handling such huge volumes of water in a short time.
Whether they are old cities like New Delhi, Mumbai, or Bangalore, or a newer city like Gurgaon, the situation is the same.
For a variety of reasons, waterlogging is a regular occurrence in every rainy season in Kolkata.
It is not only a matter of old drainage systems or cleaning them of plastic and garbage.
There is more to it.
Let’s discuss them now.
While the Highly river is on the western side of the city, the gradient of the plane is toward the east. Therefore, you need pumps to force water into the river.
The eastern side of Kolkata is full of waterbodies and marshy land and most of the rainwater flowed into it. But now it’s getting constricted and water holding capacity is coming down.
The central part of Kolkata is somewhat lower, giving it the appearance of a soup bowl. You know where the water should accumulate in such a topography.
Kolkata soil is semi-permeable alluvial and it takes time to soak up water.
Added to it is the increasing concretization of the ground surface because of various development activities, and stormwater has very limited opportunity to permeate into the ground.
Legacy of the British Drainage System
The underground sewage system of Kolkata was built way back in 1875. This is one of the most complicated systems anywhere in the world, carrying both stormwater and wastewater.
Made of bricks, this huge network is crumbling now and caving in places.
Obviously, it was built for a much less population than the city is having today. However, regular desilting and cleaning would have served it even today, but it is a formidable and costly effort.
Of course, major repair and cleaning work was done a few years back and waterflow and carrying capacity has increased since.
A city cannot be maintained by the authorities only, citizens must join hands to keep the city clean.
If Kolkata residents throw plastics and all sorts of garbage into the drains, especially plastic, they cannot but blame themselves for severe waterlogging after a heavy shower.
Hopefully, the straw ban will be enforced from July 1.
Irregular and Inadequate Desiltation of the River Hooghly
The Hooghly river carries a massive quantity of silt and it gets deposited and reduces the depth of the river. Consequently, its capacity to absorb stormwater significantly decreased.
The solution to this problem lies in regular dredging of the river so that a larger volume of water can flow into it. However, this is hardly done on a regular basis.
Similarly, there are various canals forming a network for speedy stormwater clearance. Same affliction affects them too. Poor desilting has considerably reduced their capacities.
Kolkata had many open grounds, ponds, and gardens but rapid urbanization wiped out most of them.
A network of ponds, parks, and open spaces helps store substantial amounts of rainwater.
For example, trees absorb huge quantities of rainwater. We need more trees in Kolkata as well as waterbodies.
The large waterbody in the eastern fringe of Kolkata is a Ramsar site. However, it is not properly cleaned today and is threatened by urbanization.
This is particularly rampant in the eastern, northern, and southern extended areas where unplanned urban growth took place without proper drainage, eradicating natural water retention infrastructure.
Rainwater Harvesting can Mitigate the Problem
A dedicated focus on rainwater harvesting, especially in gated communities, can mitigate the issue to a large extent.
It is desirable to store rainwater and use it for various purposes such as cleaning pathways, and gardening. If seawater can be filtered and used for human consumption, the use of rainwater purification can be explored too.
Additionally, rainwater can be used to recharge the groundwater to prevent further depletion of the water table in Kolkata.
Gated Communities are Planned to Prevent Waterlogging
Landfilling with earth and sand, and a good internal drainage network ensure freedom from waterlogging even after a heavy shower.
Nowadays, some residential projects have waterbodies inside. This, along with provisions for harvesting rainwater, ensures economic utilization of the water resource.
In this era of work from home and online shopping, you do not have to wade through knee-deep water anymore for essential work.
You can enjoy the rains, with ‘woh kagaz ki kasti, woh barish ki paani’ playing in the background while you sip hot tea and bite into a pakoda.