‘Sponge cities’ work by absorbing water, instead of repelling it, which is the norm

Cities normally manage rainwater by allowing it to flow off hard surfaces like concrete or pavement and into storm drains. When it rains too much, those drains can overflow, flooding communities. A new approach uses the power of nature to ‘naturally’ absorb the water, much like a sponge does. It’s a simple concept, but one that requires a rethink in how we plan our cities.