Pervious concrete is, basically, just concrete that allows water to flow through it. This has some benefits and detriments for urban environments, as explained on NPR's Science Friday. Frankly, though, it's kind of pleasant to just sit back and watch this patch of pervious concrete absorb 1500 gallons in five minutes.
Maggie Koerth-Baker is the science editor at BoingBoing.net. She writes a monthly column for The New York Times Magazine and is the author of Before the Lights Go Out, a book about electricity, infrastructure, and the future of energy. You can find Maggie on Twitter and Facebook.