Currently— April 13th, 2022

What you need to know, currently.

“Sponge” cities could be the future of urban planning.

Like their namesake, sponge cities absorb rainwater, runoff and storm surges, as well as replenish the water supply during droughts and repurpose excess rainwater for irrigation.

A concept proposed by Chinese researchers in early 2000, sponge cities mitigate and even prevent flooding and drinkable water shortage through working with the local environment. In 2014, sponge cities were approved as an urbanism policy and adopted by several different cities in China, including Shanghai, Shenzhen, Wuhan and Beijing. Sponge city-like projects have also been integrated into Malmo, Sweden and Philadelphia.

Sponge cities are made to improve upon the city’s existing features or reconstruct it to be better prepared for extreme weather events, rather than seriously alter any pre-existing infrastructure. Unlike traditional infrastructure that rushes the water off the land as fast as possible, sponge cities work gradually and with the water, letting it linger and then soaking up any excess as rivers and oceans swell during high tides and storms.

This is significant because as climate change worsens, water availability will dwindle and both floods and droughts will become more frequent and likely.

“Climate change will mean that any storm or drought or natural disaster will easily surpass what we have designed,” Yu Kongjian, a landscape architect at Peking University and founder of design space Turenscape, who popularized the term “sponge city,” told the New York Times. “We are too dependent on this infrastructure, so whenever a natural disaster happens it will be overwhelmingly destructive.”

However, sponge cities aren’t the only flood management model underway, as there are several other projects around the world, including low-impact development in the United States, natural infrastructure in Peru and green infrastructure in Europe.

–Aarohi Sheth