Philadelphia's Eco-Friendly Stormwater Management Approach

"Cities' usual way of dealing with stormwater has been to collect and move it off site as rapidly as possible, often with big, expensive tanks and tunnels to hold the overflow and its sediments as long as feasible. Several major U.S. cities are building precisely such facilities right now.

But the Philadelphians are aiming instead to make their entire city into a kind of great green sponge, an urban ecosystem that can handle its stormwaters and wastes far more naturally and, in the process, assure clean and reliable water for fishing, swimming and drinking."