The What and Why of Porous Paving Applications

The What and Why of Porous Paving Applications

Porous paving is a way to redesign the paved surfaces around your property, such as driveways, walkways and patios, to help manage storm water.” ~ Philly Water Sheds

Created in the 1800s, construction sites use porous paving today instead of traditional impervious paving materials. The main reason for this is that it decreases how much runoff leaves a site. However, it also promotes infiltration of this runoff into the ground, thus reducing how many pollutants the water carries off into a storm drain or waterway. Additionally, it helps reduce the peak runoff in both volume and speed.

runoff water


One of the main applications for porous paving is in land development. Here it helps immensely in creating more impervious surface. This is important when paving land for creating roads and parking lots. Some of the many benefits here include the fact that it:

  • Filters contaminants from the runoff water before it enters the storm sewer center.
  • Alleviates flooding downstream.
  • Recharges the groundwater supply.
  • Allows for land use particularly in those areas where they’d otherwise not meet the guidelines set out for storm water retention.
  • Provides better traction than concrete or pavers when there are icy conditions.


The reason porous paving works so well is because of the construction of the layers:

  • A well compacted densely graded base course material with a nominal size of 20mm (DGB20) laid to 150mm depth
  • A Recycled plastic cell structure, back filled with free draining gravel, which provided the load baring required while preventing wash out of the base layers.
  • A 25mm depth of the resin bound stone.

This construction should provided a high enough void content to allow the water to soak back into the ground or alternatively additional sub-surface ag lines may be required for a clay rich soils.

Understanding how great this material is, you may now wish to use it in your next building project. If so, we invite you to contact us. We’re happy to help you put your project together.