How Green is Your Driveway?

Green living is a favorite topic of mine, and here is an innovative way to take your home to a higher level of green.  This idea is best suited to new construction or when a complete replacement is needed.  So what can go green now?  Your driveway!

A green driveway refers not to color, but to driveways that are permeable to the elements.  Some benefits of this feature include a reduction of sewer overflow, less local flooding and less stream and river erosion.  In addition, storm water can pick up pollutants such as oil and grease from roadways and driveways.  Nutrients from lawn fertilizers along with bacteria from animal waste can also be carried into streams and waterways.  Once the polluted water mixes with fresh, the contaminants degrade water quality as well as damage the habitat of fish and other wildlife.

Conventional pavement driveways are considered impervious surfaces because of the water barrier they provide.  By repelling water, rainfall is able to flow into storm drains or sanitary sewers.  Particularly in dense urban areas, there is less land to retain storm water, which increases sewer overflow and flooding.  By choosing permeable paving options, homeowners allow rain to soak through driveways into the soil below.  In addition to decreasing flooding, this infiltration of water can help recharge groundwater supplies, filter out pollutants, and help keep drinking water healthy. 

Permeable paving options all require that a layer of rock or gravel, followed by tamped sand be placed on top of the soil to retain water until it can soak into the ground.  A three inch excavation is needed, and an overflow route for storm runoff should be directed toward landscaped areas, gardens or street drains.  A variety of paver blocks, bricks and flagstone can be purchased to cover the soil, rock and sand base.  Permeable pavements should be kept clear of mud, sediment and leaves.

Interlocking pavers have tabs to space them 1/4-1/2" apart, which allows water to flow through the joints, while remaining stable enough for cars to drive over them.  Vegetation may grow in the gaps, which will truly make it a green driveway!