Giant engineering projects didn’t solve all of Chicago’s water woes. Intense rainfalls are dumping more water on the city, resulting in more flooding. This despite about $4 billion in spending on one of the most expensive public works projects in the nation’s history. So what can Chicago do? Some point to green infrastructure — plants, trees, rooftop gardens — as one of the best ways forward. And we go to Philadelphia to see how that city is really embracing green.

Photo: Todd Melby