Los Angeles has learned to be Sponge City

Which is a good lesson to learn when you are living in a desert.

Earlier this month, the future fell on Los Angeles. A long band of moisture in the sky, known as an atmospheric river, dumped 9 inches of rain on the city over three days — over half of what the city typically gets in a year. It’s the kind of extreme rainfall that’ll get ever more extreme as the planet warms.

The city’s water managers, though, were ready and waiting. Like other urban areas around the world, in recent years L.A. has been transforming into a “sponge city,” replacing impermeable surfaces, like concrete, with permeable ones, like dirt and plants. It has also built out “spreading grounds,” where water accumulates and soaks into the earth.

With traditional dams and all that newfangled spongy infrastructure, between February 4 and 7 the metropolis captured 8.6 billion gallons of stormwater, enough to provide water to 106,000 households for a year. For the rainy season in total, L.A. has accumulated 14.7 billion gallons.