"This will take a lot of pressure off of storm-water draining, and maybe we can get a handle on flooded basements," said at-large Councilman Jim Kenney. "The less water we have to treat, the better we are economically and environmentally."
A porous street is made up of permeable materials including porous asphalt, which is specially designed to allow water to soak through the surface, thus eliminating storm-water runoff.
Beneath the porous pavement lies a layer of stone that acts as temporary storage for water as it slowly soaks into the soil.
The Green Street initiative is a part of the Philadelphia Water Department's Green City, Clean Waters program, an effort to improve the city's sewer infrastructure and reduce the amount of storm water that enters it.
Similar to most older cities, parts of Philadelphia have a combined sewer system that includes both the sanitary sewer system - water from showers and toilets - and a storm-water system, said Andrew Stober, chief of staff for the Mayor's Office of Transportation and Utilities.
During heavy rain, treatment plants can't accommodate the water, and consequently the toilet and storm water flows together into the city's rivers.
"This happens 50 or 60 times a year," said Stober. "We've created a street that can literally absorb water. [This is the] first of its kind, the first of many."
Percy Street was completely reconstructed with a new sewer system, main and piping.
Construction of the city's first porous street cost $330,000, including the sewer, water and gas lines and the permeable pavement.
The city will complete its second porous street, on Webster between 13th and Broad, later this spring.