When heavy rains hit a concrete or asphalt driveway, the water runs off and into the street causing gutters and sewers to overflow, eventually reaching and polluting large bodies of water like rivers. Even during light showers, water cannot enter the soil through an impermeable driveway. This disrupts the water cycle, and because the water isn't being naturally filtered through soil, chemicals and other pollutants wash into our waterways. Installing a natural driveway allows rainwater to stay in the water cycle and helps reduce up to 80 percent of the pollutants in storm water runoff. (See Reference 2)
In a turf block driveway, blocks of concrete with gaps in the center are laid flat with the gaps facing upward. Once the driveway is completely laid out, the gaps are filled with soil and ground cover plants that can handle being walked on and driven over. The plants help stabilize the driveway and absorb some of the rainwater. Although grass will work well in most regions, the best choice for your filler plant is a drought-tolerant species suited to your area's climate. (See Reference 1)
Gravel-fill block, also known as aggregate-fill block, is similar to turf block. Concrete stones with gaps in the center are laid flat over the entire surface of the driveway. Instead of plants, the gaps are filled in with pea gravel. The surface of the driveway is porous, allowing rainwater to flow through, but you don't need to maintain any plants. Because there are no plants to water, this is a good solution if you live in an arid climate.
Pavers are interlocking pieces of concrete that fit together end-to-end and side-to-side. The pavers come in various shapes from simple squares to ones that resemble flagstone. Typically, the entire driveway is laid out with sand filling in any small gaps. Because the pieces fit together like a jigsaw puzzle and don't use any mortar, rainwater can flow through the gaps and into the ground below. A paver driveway takes little effort to maintain and, if a paver breaks, it can be removed and replaced for only a few dollars. Another natural driveway idea using pavers is to lay out the pavers in two parallel rows for your car to drive on, and fill in the center with a ground cover plant. (See Reference 1)
If you like the look of a traditional driveway, but want the environmental benefits of a natural driveway, consider pervious pavement. This pavement is made with similar materials as regular asphalt or concrete, but the material is joined together to allow gaps in between the pieces of aggregate. The gaps allow water to percolate into the soil below. Because of the gaps, this pavement is also less prone to cracking from temperature changes than traditional concrete. (See Reference 1)
Based in Portland, Ore., Tammie Painter has been writing garden, fitness, science and travel articles since 2008. Her articles have appeared in magazines such as "Herb Companion" and "Northwest Travel" and she is the author of six books. Painter earned her Bachelor of Science in biology from Portland State University.