Indian cities must become ‘sponge cities’ to tackle urban flooding
Urban flooding has become a recurrent feature in Indian metros. If it was Mumbai yesterday, it is Bangalore today. It is true that this year has been the IT hub’s wettest year in at least 115 years, but that’s not the only cause for the collapse of Bangalore. The reason for such mayhem is along with crumbling infrastructure and drainage system, there is no long-term vision on how to tackle such climate challenges. This lack of a proper plan is criminal neglect on the part of the State since the intensity and frequency of these events have been increasing. In the last couple of years, Mumbai, Ahmedabad, Chandigarh and Chennai have faced the same challenge.
One of the key reasons why cities are collapsing due to natural calamities is because we have gone against the natural systems. While natural systems retain water, concrete structures tend to waste it. So when we build cities, we tend to build on wetlands and ponds, which actually have the ability to soak in extra water. But experts point out that the solution to such urban flooding is to mimic nature, by making cities act as a sponge or becoming “sponge cities”.
Take for example, Berlin. The city’s Rummelsburg neighbourhood is investing hugely on green roofs with swales (a low or hollow place), urban wetlands, gardens and parks, and permeable pavements to soak in the extra water and also keep the city cool. According to Mother Nature Network, China too is investing in their growing cities in this way, and test projects show that keeping rainwater local works. They have set an ambitious goal that began in 2015. By 2020, the government has decreed that 80% of 16 urban areas should absorb and be able to use at least 70% of rainwater, and they’re even teaching the concept in elementary schools. So far, they’ve spent about $12 billion.
This regular collapse of the city must worry India since we are urbanising and moving from an agrarian economy to a GDP dependent mainly on industries and services that operate from urban India.