West St. Sidewalk Permeable Pavement
West St. Sidewalk Permeable Pavement
West St. Sidewalk Permeable Pavement
Where is this located? It is the sidewalk on the left side of West Street when heading up hill from Squalicum Way.
What’s special about this place? The sidewalk next to West Street is made of porous asphalt which allows rainwater and melting snow to soak directly into the ground below this sidewalk. This prevents the water which carries sediment, leaves, and other pollutants from flowing down the hill into Squalicum Creek. As the runoff soaks into the ground, nutrients and other contaminants are removed and broken down by bacteria in the soil. With the sidewalk’s proximity to Squalicum Creek, this is an ideal solution on this steep hill for reducing urban runoff into the creek.
About Permeable Pavement
Permeable pavements include pervious concrete, porous asphalt, and spaced pavers, which are installed over special layers of sand, gravel, and soil. Pervious concrete and porous asphalt have small spaces that allow stormwater to soak through them, while interlocking pavers allow water to soak between the pavers. In addition to reducing runoff, permeable pavements help filter out pollutants. Because they are capturing and retaining pollutants, it is necessary to regularly clean the pavement or gaps between pavers to maintain their permeability.
Water quality benefit: Permeable pavement surfaces are effective in managing runoff from paved surfaces because they capture and absorb stormwater runoff at the source. When water soaks through permeable pavements, it prevents pooling of water on the surface. Permeable pavements are also effective at trapping pollutants as the runoff filters through the underlying layers of sand and gravel.
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The porous asphalt material here provides a low-cost, high-impact reduction of urban runoff flowing into Squalicum Creek at the bottom of this hill.
The pervious sidewalk next to the entrance to Columbia Neighborhood provides onsite protection for Squalicum Creek's water quality.
The porous asphalt used here eliminates the need for costly drainage systems. It's rough surface also creates good traction for the hill slope here.
Here is a close up of porous asphalt which eliminates the need for costly drainage systems. Its rough surface creates good traction on the hill slope.
Porous asphalt requires a compacted base comprised of sand and crushed and washed gravel. Rain falling on this sidewalk soaks into the soils below.
