Landscaping has historically been about marrying form and function, the beautiful and the practical. In recent decades, however, a third dimension has been added to the fray: concern for the environment at large. Permeable pavement is an example of all three: beautiful, practical, and ecologically-friendly
In a basic sense, conventional paving is largely non-permeable, and thus stormwater flows off of it into gutters, and down into the sewer system, where it brings with it pollutants and particulate matter. Permeable pavement allows stormwater to infiltrate and eventually recharge groundwater reservoirs, while being filtered where it falls.
A 2003 study from the journal Water Research showed that permeable pavement completely filtered out motor oil and diesel in water samples, and also significantly reduced levels of heavy metal pollutants such as copper, lead, and zinc.
There are many forms of permeable pavement, and choices for homeowners depend largely on budget, aesthetics, and local building codes or architectural controls.
Permeable paving options that are almost visually indistinguishable from normal paving are porous asphalt or porous concrete. They look the same as asphalt or concrete, but have small channels through which water drains to the subsoil layers.
Interlocking concrete pavers are also a popular option, and can lend themselves to beautiful designs: from rustic-looking cobblestones, to modern granite slabs, to “green” paving with diamond-shaped grass patches.
Modular systems like plastic turf reinforcing grids and geocells are honeycombed subsurface systems, usually placed over gravel and topped with grass. They reduce soil compaction and redistribute the weight of vehicles, and are like an invisible permeable paving that can be installed below a lush grass plane.
Every paving project is different in terms of budget and aesthetics, so in choosing the best option, it’s best to talk to a professional who can factor in the local conditions and provide an expert recommendation on the best kind of permeable pavement for a site.
Far from just being an ecologically-sound choice, permeable pavement is increasing in popularity, and may even increase property value by reducing the risk of flooding: water that is dispersed as it infiltrates the subsoil is far less likely to disrupt infrastructure like foundations. Additionally, permeable pavement is cooler than non-permeable options, owing to the high heat capacity of water, which slows the rapid heating of materials like asphalt and concrete.
Permeable pavement can provide ecological, infrastructural, economic, and aesthetic values to any building project, and are a worthwhile option to consider over conventional paving.