"Use parks to create places people want to hang out in and manage stormwater at the same time," says Inga Saffron, the Pulitzer-prize wining architecture critic for the Philadelphia Inquirer. "The city is under federal mandate to reduce its overflows into rivers when it rains heavily. Moreover, Philadelphia has a real shortage of green space. So it combined these two ideas: Instead of building twenty-five-inch pipes, they will use greenspaces to absorb rainwater. It's the most sustainable thing Philadelphia is doing." Photo 6 of 8 in Game-Changing Ideas for a Sustainable World

Game-Changing Ideas for a Sustainable World

6 of 8

"Use parks to create places people want to hang out in and manage stormwater at the same time," says Inga Saffron, the Pulitzer-prize wining architecture critic for the Philadelphia Inquirer. "The city is under federal mandate to reduce its overflows into rivers when it rains heavily. Moreover, Philadelphia has a real shortage of green space. So it combined these two ideas: Instead of building twenty-five-inch pipes, they will use greenspaces to absorb rainwater. It's the most sustainable thing Philadelphia is doing."