Sponge Cities

As outlined here, sponge cities are urban areas with enough natural features that can absorb rain and prevent devastating flooding. Natural features such as urban gardens, green boulevards, parks, lakes, streams, really any other type of areas that will absorb water. Global precipitation is increasing on a yearly basis, so any effort cities can do to mitigate the increasing rainfall will be important.

Recently, an AI analyzed and ranked seven cities on their “spongability.” The AI analyzed New York, London, Singapore, Mumbai, Auckland, Shanghai and Nairobi. Here are the results:

1. Auckland, New Zealand came in first, at 35% spongey

2. Nairobi, the capital of Kenya, is second at 34% spongey

3. New York, Mumbai and Singapore are all at 30%

4. Shanghai go a rating of 28%

5. Lastly, London came in at 22% due to high levels of concrete and low levels of soil absorbency

As cities add in more sponge elements, the level of spongability can increase. There are several cities around the world that are incorporating sponge elements, such as Freetown in Sierra Leone who is planting trees to help prevent floods and landslides. Or Tirana in Albania who is planting a ring forest to clean the air and prevent further urban sprawl.

Do you have any examples of “sponge” elements you’ve come across in various cities?