When you think about ways to greenify your home, you probably don’t think about pavement. Most environmentally savvy homeowners start reducing their carbon footprint by replacing old light bulbs with CFLs or moving their homes off the grid. What even the most sustainable homeowners don’t realize is that replacing the pavement in your driveway or blacktop can be an even more effective change.
There’s no denying the importance of reducing your home’s dependence on fossil fuels, but it’s equally important to help preserve our planet’s supply of fresh water. In cities especially, it’s critical to limit the amount of stormwater runoff that makes its way into the water supply. Runoff pollution is the source of some of the most infamous environmental hazards like the Gowanus Canal in Brooklyn, New York.
The way this insidious threat works is actually quite complex. Older cities have what are called mixed sewer systems – mixed because they are designed to catch both sewage and excess stormwater. When rainwater isn’t absorbed into the ground either due to paving or volume, that rainwater becomes toxic runoff. In mixed sewer systems, the toxic runoff blends with raw sewage, ultimately overflowing the system and polluting the water supply.
One of the most effective ways to address this problem is pavement removal. Paved surfaces are nightmares when it comes to water absorption. Chemicals in the paving surface increase the pollution in runoff, while the surface itself redirects stormwater that would otherwise be absorbed and purified by the water cycle into sewer systems. By choosing an environmentally friendly pavement substitute for your driveway, you can greatly diminish both effects on the water supply.
If you absolutely need a hard surface, try paving stones or gravel. Gravel driveways allow rainwater to drip between small cracks in the surface to reenter the water cycle. Stones work in a similar fashion. Both surfaces, while not ideal, have a much lower impact on the water supply.
Semi-permeable pavement is another green option. Thanks to modern technology, scientists are now able to manufacture pavement with permeable properties. These driveways look just like conventional blacktop, only they allow water to reach the soil beneath. Traditional blacktop is impervious to water. Excess stormwater pools on top of the surface and runs off into the sewage system. Semi-permeable pavement allows most of that same stormwater to soak through the blacktop.
Gravel, paving stones and semi-permeable pavement are all perfectly viable options, but true green spaces are the ideal solution. Green spaces filled with native plants, trees and ponds will help you maximize water absorption. If you live in a dense urban area and you don’t have enough property to maintain a typical green space, consider one of the many creative options available. In cities like New York and Chicago, green roofs are becoming popular stormwater solutions. By converting your hardtop roof to an absorbent garden you can have a dramatic effect on the ecology of your block. Many ecologically minded urbanites have successfully grown vegetables and flowers on their green roofs. The possibilities are truly endless.