Environmental Issues When Constructing a Driveway

No one would have thought twice about paving over a garden for a driveway ten, or even five years ago, but with 'green' issues now firmly in the public eye the ecological impact of this practice has come under increasing scrutiny. And it's not just paving over for driveways that's attracting attention. With increasingly busy lives being led, householders aren't finding the time to look after large gardens and are covering them over with patios and other hardstandings that are easier to look after.

Flooding and Quality of Life

The impact of paving gardens over is to send rainwater straight down into storm drains or sewers. A lawn or garden will soak up the water and hold it up, slowing it down and allowing the sewers system to catch up, particularly in times of heavy rain and flooding.

Having fewer plants around to soak up carbon dioxide and release oxygen obviously makes the environment worse, and another effect on our lives is that hard surfaces soak up heat during the day and release it at night, making the stuffy effect even worse. Subsidence can be a problem too. National insurance company Esure have also come out against hard surfaces, saying that they prevent water getting to the soil below, which then dries out and shrinks, in particular with soils that are predominantly clay.

As well as all of that there is the impact on the animal and plant life. The lack of places for small organisms, insects and the like means less food for small animals and birds.

Action to be Taken

Taking London alone, studies of aerial surveys by the London Assembly have shown that over 12 square miles of front garden are now paved over and there were 120,000 applications for dropped kerbs in five years. The concerns are now so great that the government intends to introduce planning permission requirement for paving over any garden area in England in 2008

Permeable Surfaces Can Ease the Drainage Problem

So does this mean that it’s all over for drives in our front gardens? Not entirely. Most of the problems outlined above occur with non-permeable surfaces such as concrete, tarmac and large interlocked blocks. Careful selection of a permeable top layer will allow water to drain through the surface and get to the ground below,

Some brick pavers that interlock but leave tiny cracks between each one will help with the drainage, as will gravel. But in both cases care needs to be taken over the compacted aggregate that supports the driveway, to make sure water can drain into the surrounding soil

Providing For Wildlife

The only problem that these products don't solve is the absence of plants and trees where animal life can prosper. This can be dealt with by laying down hard tracks for each wheel rather than paving the whole garden, which allows you to keep sections of lawn and borders with shrubs and flowers.

Alternatively there are an increasing number of surfaces that are hard enough to take a car but allow grass to grow through them. Look for grass reinforcement products; they are usually meshes of concrete or plastic that you can lay down over a substrate, then grass can be seeded in the gaps of the mesh.