Feel at home with an environmentally friendly drivewayNext time it rains, look out your window and watch the water and contaminates from the road slosh into the sewers and contaminate our water supply.

“Green pavement,” a relatively new concept in green building, is a permeable and porous pavement that absorbs rainwater instead of repelling it. It combines the load-carrying capacity we expect of paved areas with the water-infiltration qualities of natural ground cover.

Here’s a look at how this environmentally friendly setup works.

There are three types of permeable pavements:

1. Plastic pavers: A plastic honeycomb grid in which grass or other vegetation can grow

2. Concrete pavers: Concrete blocks withspaces in betweenthem for better drainage.

3. Asphalt/concrete: Fine particles are left out of it to make it more porous.

Common uses forpermeable pavement:

- Driveways

- Emergency access lanes

- Public parks

- Alleys

- Parking lots

- Bike or walking paths.

DID YOU KNOW?

Green pavement is strong enough to hold a helicopter:A 100-sq/m area of lawn at Buckingham Palace was replace with a turf system for a helicopter landing pad. Helicopters, which had been previously landing on the lawn, were causing coinsiderable damage to the area which required constant repair.

PROS OF GREEN PAVEMENT

- Green pavement is permeable and porous — absorbs water instead of repelling it.

- Water is returned to the ground instead of being washed into the sewers.

- Many green pavement products are made from recycled materials.

- Can eliminate the need for gutters and storm sewers.

- Doesn’t ice up as quickly in the winter as water does not pool on the surface.

CONS OF GREEN PAVEMENT

- Pavers can be a problem for snowplows. Plow blade can catch on corner of pavers and rip it up.

- Prone to clogging.

- Porous pavement is more expensive that traditional pavement.

- Sand and other fine sediment can block the spaces between pavers. Sanding in the winter can contribute to clogging.

- Not for use on highways or airports where there is a lot of heavy braking.

TRADITIONAL PAVEMENT

Runoff: (Water from the roads that runs into the sewers)

- Contributes to flooding, erosion, contamination of water supplies

- It can contain oil, grease, pesticides from turf management, road salts, and toxic chemicals from automobiles

- Runoff occurs because traditional pavement is nonporous — meaning it doesn’t allow rainwater to settle back into the ground

PERMEABLE PAVEMENT

Water percolates, as in a coffee pot, when it seeps through the pavement to a cleansing layer of gravel. The gravel or stone acts as a natural filter, clearing the water of pollutants.

Home Improvement Toronto