Permeable Paving

  
   

Tianwen Zhou + Harley Pan - Winter 2011

 
   
Introduction  
Permeable paving is composed of a range of materials and techniques for paving roads, cycle-paths, parking lots and pavements that allow the movement of water and air around the paving material. Although some porous paving materials appear nearly indistinguishable from nonporous materials, their environmental effects are qualitatively different. Whether pervious concrete, porous asphalt, paving stones or bricks, all these pervious materials allow precipitation to percolate through areas that would traditionally be impervious and infiltrate  stormwater  to the soil below. The material has been used and developed since the 1970s and landscape architects have been instrumental in its development. Porous pavements are beginning to gain acceptance, but deserve to be better known for the many benefits they provide.
Advantages:
    • Manage runoff, prevent serious erosion and siltation in surface water bodies;
    • Control pollutants, capture the heavy metals that fall on them, preventing them from washing downstream and accumulating inadvertently in the environment. In the void spaces, naturally occurring micro-organisms digest car oils, leaving little but carbon dioxide and water; the oil ceases to exist as a pollutant.
    • give urban trees the rooting space they need to grow to full size.