There are various benefits to using porous paving materials including environmental, structural, economic, and low maintenance. The appearance of porous paving is similar to other materials used for pavement, but the mixtures are quite different because of the particles used during mixing. Porous paving is a permeable surface that consists of larger stones than the fine particles often used in concrete, and this particular difference promotes water infiltration. The consistency of this pavement is the primary reason it is a valuable environmental aid.
Environmental benefits of this pavement are based on the pavement's allowance of water to filter through the voids between the gravel in the mixture, return to the ground, and assist in naturally refilling groundwater reservoirs. Other pavement and water pathways often redirect the water, which deprives the groundwater supply and skips the filtering process of pollutants that soil naturally provides. There is a chain reaction when groundwater is not recharged and can ultimately effect small bodies of water and local wells. Although porous paving is not often recommended for high traffic areas, there are many private and low traffic areas that can benefit including walkways, driveways, patios, or minimally used roads and parking lots.
The structural benefits are primarily the strength and length of time before needing to be replaced or repaired, and porous paving can sometimes last over 30 years. The pavement requires smaller amounts of water to prepare than concrete. It can usually be laid in a smooth run without visible seams from joints because the lack of water used helps prevent shrinkage, which can lead to cracks. Due to the large material included in the mixture, the porous paving has a textured appearance that provides friction and helps minimize hazards caused by slippery surfaces.
Economically, porous paving benefits in the long run because other costly water recharge methods that often include pipes, retaining ponds, and other materials to guide or redirect water flow are unnecessary. Depending on the application technique used, the prices can vary but may be slightly higher than alternative pavement types. Larger development projects especially benefit from the cost savings of drainage installation because of the size of the systems that would be required to suit the neighborhood.
There are additional porous treatments that can be used, including porous asphalt and porous turf. The primary goal of using permeable material is to aid the water supply. Most impermeable pavements and structures prevent water from reaching its destination, which can cause flooding because the abundance of impermeable objects does not allow the water to be absorbed, and leads to water accumulation.