Deep below our city streets lie intricate networks of underground piping built to carry away excess rainfall run off. These stormwater systems mostly go unnoticed until heavy rains overwhelm them, causing streets to flood. Now, with rising rainfall averages in much of the nation, cities need to plan for more water. Guest host Dan Charles talks to climate correspondent Lauren Sommer about the challenges of such planning and why many cities aren't set up to handle the coming rains.