Urban alleyways conjure images of dark, slimy, creepy things. They’re places where only the Teenage Mutant Ninja Turtles should hang out. But Chicago, the city with the most alleys in the world (1,900 miles of them to be exact), is transforming theirs into cleaner places as a part of the new Green Alley Program. The plan is to repave them with permeable materials to benefit the environment. Here’s how:

1. Pavement absorbs water that then goes into the earth reducing flooding and saving tax payer money which would otherwise be spent treating storm water
2. The pavement is a light color so it reflects heat and is cooler, reducing the “urban heat island effect”
3. They’re made of recycled materials
4. Lights in the alleys will be energy efficient

Green alleys aren’t exactly the first thing that comes to mind when I think of ways to reduce the effects of climate change, but I think urban renewal projects like this one can really make a difference in the long run.