Sponge Cities

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With cities increasingly drowning in their own runoff, urban flooding has become a common sight from Chennai to Belagavi. As traditional drainage systems fall short, the innovative concept of "Sponge City" offers a fresh perspective, making urban spaces more absorbent to manage excess water. While the vision sounds promising, can concrete-dense cities really transform into water-soaking sponges?

Mumbai | Source: Unsplash

As soon as the monsoon knocks India, the news is filled with cases of urban flooding in the cities across the country. Not just India; increasing trends of urban flooding have now become a universal phenomenon and pose a great challenge to city administrations worldwide. Defined as the “inundation of land in a built environment, particularly in densely populated areas”, urban floods are caused by excessive runoff in developed areas with poor drainage systems.

Problems associated with urban floods vary from relatively localised incidents to major incidents with widespread impacts. Flooding events not just in bigger cities like Chennai, Mumbai, Hyderabad, and Bengaluru but also in smaller cities like Belagavi and Dharwad are a testament to the fact that the risk of floods in urban areas has increased and will continue to increase.

To curb the damage caused, it is important that cities adopt better urban flood management techniques. Lately, ‘Sponge City’ has emerged as a new design paradigm in this space.

The idea of a sponge city is to make cities more permeable, to hold and use the water which falls upon it, much like the natural sponge.

Qian'an City - one of China's Sponge cities | Xinhua Net

A wide range of benefits are associated with the implementation of sponge cities; however, the main challenge lies in the implementation and availability of land because a sponge city needs to be abundant with spaces that allow water to seep through them.

Experts suggest that there is no one-size-fits-all approach to the design and implementation of sponge city strategies. They also believe that to convert a city into a sponge city, the administration should first focus on existing infrastructure that can soak up excess water.

China is already fighting flooding with sponge cities and Indian cities like Chennai, Mumbai, and Kochi are currently studying and planning to develop a sponge city roadmap.

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To know why Sponge City is being considered as an effective solution for urban flood management, read more.