Philadelphia is moving forward with a 20-year, $1.6 billion stormwater control plan that incorporates many green aspects. Included are plans to convert impervious surfaces into absorptive spaces that use soil and vegetation to collect and filter runoff, including green roofs, water gardens, and the restoration of streams flowing through the city their natural ecology.
The need to deal with sewer overflow events is an issue that many large cities in the United States are dealing with, with increasing pressure from the U.S. Environmental Protection Agency and state regulators. The city estimates that the green approach, as opposed to building large-scale underground storage facilities, will yield an additional dollar in benefits to the city.
Read more in this ENR story.