GEF

Unit 5  |  Toward Sustainable Water Systems 132 The city of Philadelphia in Pennsylvania has replaced some standard pavement with permeable paving as a part of an overall investment in green infrastructure that is designed to increase water quality and prevent storm water runoff. Their “Green City, Clean Waters” program, adopted in 2011, is an innovative approach that ties together development, infra- structure, and restoration of aquatic habitats to improve water quality and keep water affordable. Philadelphia and other cities are also investing in natural filters such as roadside plant- ings, which allow rainwater to trickle slowly back into the water table while being cleaned. Green roofs provide many environmental, social, and economic benefits. Another green building innovation is the use of green roofs . These roofs are covered with an impermeable layer and soil and planted with a variety of plants. Green roofs offer a variety of benefits, including reduced water runoff, building tempera- ture moderation, and the provision of wildlife habitat and space for native plants. Some green roofs are even used to purify and store rainwater to supply the building’s water needs. GREEN ROOFS Roofs using a multi-layered structure of plant materials that is designed to protect buildings while also manag- ing storm water runoff. ?  DID YOU KNOW Outdoor faucets can release more than 6 gallons of water per minute.