What is porous pavement?
Porous pavement is a surface material that allows rainwater to filter through the surface to a stone reservoir beneath it. From there, rainwater can infiltrate deeper into the ground and recharge aquifers, making it a practical and effective stormwater management tool. It can be made of gravel, recycled rubber, even asphalt and concrete, and it has a multitude of applications.
Porous asphalt and concrete can be used for sidewalks, driveways and parking lots. Poured-in-place bonded recycled rubber is perfect for playgrounds and trails where it offers a forgiving spongy surface underfoot.
So, why is it important to use porous pavements?
Stormwater management is a pressing issue throughout the U.S. because many cities and municipalities have what is called combined sewer systems. These systems handle both household waste water and stormwater, where it is transported to sewer treatment plants for cleaning. Because of the immense amount of impervious surfaces (those surfaces that don’t allow water to infiltrate into the soil below), the amount of stormwater runoff is overwhelming to the treatment plants.
In turn, both the stormwater runoff and waste water ends up in our rivers and streams without first undergoing treatment. This water now contains dangerous levels of bacteria, pollutants (oil, trash, etc.) from the street and heated water (from flowing over hot paved surfaces). The effects are devastating on aquatic creatures and plants that live in our waterways, and our own drinking water supplies become contaminated, as well.
So, in areas where paving is necessary, porous pavements can reduce our impact on the environment. Learn more about stormwater management on your own property in my previous post here.
Photo above of Herron Park, Philadelphia, which features a porous recycled rubber surface for the playground. The surrounding neighbors welcomed the transformation of the basketball court where the sound of bouncing balls is absorbed by the porous asphalt surface! And, the addition of rain gardens and dozens of trees and shrubs bring nature to this city block. Courtesy of Langan.