Permeable Paving

In new suburban growth, porous pavements protect watersheds. In areas already built out, old town centers, redevelopment and reconstruction are opportunities for environmental rehabilitation. Permeable paving is an important component in sustainable urban drainage systems (SUDS).

The infiltration capacity of the native soil is a key design consideration for determining the depth of base rock for stormwater storage or for whether an underdrain system is needed.

Advantages of permeable paving

Permeable Paving

Permeable paving surfaces have been demonstrated as effective in managing runoff from paved surfaces. Large volumes of urban runoff causes serious erosion and siltation in surface water bodies.

Permeable paving surfaces keep the pollutants in place in the soil or other material underlying the roadway, and allow water seepage to groundwater recharge while preventing the stream erosion problems. They 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. Rainwater infiltration its built-in stormwater management, is usually less than that of an impervious pavement with a separate stormwater management facility somewhere downstream.

Porous pavements give urban trees the rooting space they need to grow to full size. A “structural-soil” pavement base combines structural aggregate with soil; a porous surface admits vital air and water to the rooting zone. This integrates healthy ecology and thriving cities, with the living tree canopy above, the city’s traffic on the ground, and living tree roots below.

With more advanced paving systems the levels of maintenance needed can be greatly decreased, concrete block permeable paving requires no more maintenance than regular concrete paving as the grit between the blocks enhances the filtering properties of the pavement. Also, in a large storm event, the water table below the porous pavement can rise to a higher level preventing the precipitation from being absorbed into the ground. The best way to prevent this problem is to allow for adequate rain water run off at the pavement design stage.

Please do not hesitate to contact us for further information on Permeable Paving.