Since residential rooftops account for a pretty significant amount of impervious cover, "Green Homes" is an element of the Philadelphia Water Department's ambitious Green City, Clean Waters program to which anyone can relate.
PWD is working with homeowners to help them initiate projects to lessen the amount of rainwater that runs from rooftops into the City's storm drains, because this rooftop runoff adds more water than the sewer system can handle during flash storms--resulting in polluted water flowing into local streams, rivers, and creeks.
Green Homes brings small-scale solutions to the City's neighborhoods: projects like installing rain barrels, rain gardens, and flow-through planters to capture runoff when it rains. For the more ambitious, actions might include de-paving, planting trees, or building green roofs. Becoming the greenest city in America means everybody is doing their part.