Less expensive permeable driveway pavers can be solid pavers that are spaced in such a way as to allow water to drain between them. These are made from stone, concrete, brick, or decorative concrete. Others are made from concrete that is actually porous. These pavers allow water to drain through their entire surface. Both offer environmentally friendly benefits, with porous pavers of course being the more effective of the two.
There are many things that a pervious hardscape does for a Houston landscaping design. One of the most important benefits that it offers is its ability to help maintain groundwater levels. Groundwater is essential to the roots of vegetation. In particular, trees with very large, extensive roots systems require groundwater several feet deep to maintain their vitality.
A driveway made from an impenetrable material can cause a great deal of trouble for trees planted to near the pavement. If a large number of their roots grow under the hardscape, they will not receive the full amount of water. This can result in stunted growth, defoliation, or even disease.
Permeable driveway pavers, on the other hand, will filter water straight to these root systems. Smaller shrubs, rose bushes, and even ornamental lawn grasses lining the driveway edge also benefit from the more even distribution of rainwater that this type of driveway design facilitates.
Smaller driveways can be built using solid concrete or stone laid over a crushed stone base. Crushed stone and sand are then used to fill the spaces between pavers, creating places between the edges where water can filter.
Larger drives and motor courts should be built of permeable driveway pavers that are made from porous concrete. This is often more expensive, but well worth the investment when a very large portion of the front yard is covered by hardscape. Porous concrete is an aggregate of stones and cement that contains considerably less sand than other forms of concrete. This creates tiny holes that water and air can filter through.
Air is just as important as water to certain types of plants. Many roots need it as much as water. Permeable driveway pavers made from porous concrete will provide better aeration for the soil. This will help many of the smaller, ornamental plants, and indigenous plants retain their color throughout the year.
During the winter months, when we often get more rain than we do in late summer, this type of driveway design has proven one of the most effective methods of erosion control. Storm water can come down with such force that it accumulates in streets faster than the storm sewers can drain it away. Driveways flood next, and when the water recedes, soil around the driveway is carried away.
Permeable driveway pavers will allow storm water to drain into the pavement and filter through a foundational layer of crushed stone. This keeps water from spilling over the pavement edge and washing away everything that surrounds it. If there happens to be pollutants such as motor oil, antifreeze, or other fluids that drip from vehicle undersides, these toxins will be trapped below the crushed stone foundation long enough for bacteria to biodegrade them.