Arup global sponge cities snapshot

This paper examines seven cities across the world with different urban profiles – from the densely packed Mumbai to Auckland, which is known for its generous public parklands. Each city was given a sponginess rating based on three major factors: the amount of green and blue space within the urban environment; the hydrogeological properties of the soil in each city, and the water runoff potential for green areas.

This report aims to get people talking about how we can move beyond concrete solutions, as we help cities cope with increasingly heavy rainfall and other impacts of climate change. Our cities aren’t just concrete jungles. Every blade of grass, every tree, pond, lake and lump of soil together form vital infrastructure. Cities need to commit to understanding and quantifying this natural infrastructure and learn how to enhance it