Sourced from Environmental Leader
Philadelphia has long struggled with stormwater that sends massive amounts of polluted runoff into nearby rivers. Rather than spending nearly $10 billion it didn’t have on a new 30-mile-long tunnel, the city is investing a fraction of that on thousands of “green” infrastructure sites.
And the strategy is paying off, Bruce Stutz reports in Yale Environment 360.
The city is seven years into a 25-year project designed to reduce 85% Philadelphia’s combined sewer overflows by 85% under an agreement with the EPA, Stutz explained. “The city is investing an estimated $2.4 billion in public funds — to be augmented by large expenditures from the private sector — to create a citywide mosaic of green stormwater infrastructure.”
Called Green City, Clean Waters, the city’s project recreates living landscapes that once slowed, filtered, and consumed rainfall. Ranging from downspout planters to complex bioretention swales that have drains running underneath them, the green infrastructure sites are intended to work in tandem with rain gardens, tree trenches, green roofs, and urban wetlands, Stutz reported.
“In the end, Philadelphia hopes by the mid-2030s to create the largest green stormwater infrastructure in the United States,” he wrote.
Progress toward the goal is measured by “greened acres” that manage stormwater runoff. So far, Philadelphia has built around 1,100 greened acres and has plans for another 1,300 over the next three years, according to Stutz. “[T]he green infrastructure already is exceeding targets for stormwater overflow reduction, cutting that volume by 1.7 billion gallons — nearly three times the original projection.”
A Break on Stormwater Fees
Each public greened acre can cost in the ballpark of $250,000 to $300,000. However, most of the greened acres completed in the city by the end of last year were on private property, encouraged by redevelopment or incentives.