Permeable Pavements for Your Driveway
If you are building a new driveway or replacing an old one, consider choosing a permeable surface. Permeable pavement is attractive, low maintenance, environmentally friendly, and relatively inexpensive.
Although permeable pavement technology is not yet durable enough to withstand high traffic areas like busy roads, it works well for residential areas and other low-to-moderate traffic surfaces. The city of Chicago has even started a project to replace 1900 miles of alleyways in the city with permeable paving, in order to reduce stormwater runoff pollution affecting Lake Michigan and problems with flooding basements due to improperly drained, 19th century alleys that are unconnected to the sewer system. Chicago's US Cellular Field, home of the White Sox, also currently hosts the largest permeable parking lot in the country.
Benefits of Permeable Interlocking Concrete Pavements
Benefits of Permeable Pavement
- Reduces stormwater runoff. Stormwater runoff from streets, driveways, and parking lots is a major source of pollution in lakes, rivers, and streams. When permeable pavement is used, however, the water is absorbed by the ground, where microbes filter all but the most concentrated of pollutants as it sinks down into underground aquifers. This not only replenishes the aquifers, reducing the frequency and severity of water shortages during drought, it also decreases the frequency of flooding as sewer systems swollen with runoff discharge into rivers and streams.
- Reduces the "heat island" effect. Urban areas are an average of 2-6 degrees warmer than surrounding countryside, thanks in part to the large quantities of heat-storing asphalt. The urban heat island effect can lead to higher cooling bills and carbon emissions, as well as more heat-related health problems in the summer. Depending on the type of permeable pavement used, permeable pavement has a higher albedo level, which causes heat from the sun to be reflected back into the atmosphere at higher levels, rather than being absorbed and stored by the pavement. Many porous pavements incorporate grass or other low growing plants, which also have a cooling effect as they transpire moisture into the air.
- Improves the health of nearby plants. Many plants have trouble growing in areas with large amounts of impervious pavement because it blocks air and water from reaching their roots. Permeable pavement allows a wider range of plant species to thrive near roads, while many porous pavements incorporate plants directly into the surface. Greater health and diversity of plants in urban areas increases natural beauty, improves habitat for birds and other wildlife, improves air quality, and combats the urban heat island effect.
- Reduces erosion. Permeable pavement protects the soil it covers from erosion as well as traditional pavements, and reduces runoff-related erosion to surrounding soil, stream beds, and other areas.
- Reduces accidents. Permeable pavers provide better traction, especially in snowy or icy weather, reducing the chances of slips and falls. Icy conditions on permeable pavement are also reduced, because when ice melts on permeable pavement, it sinks into the ground, rather than pooling and refreezing as it does on conventional pavement.
Pervious Concrete Installation and Demonstration
Permeable pavement of any kind should not be installed on soils with low permeability themselves, nor should they be installed in areas with a high probability of toxic spills.
When installed properly, they hold up well in winter conditions, but sand and salt should not be spread on them, as they can block the pores and prevent proper drainage, or contaminate groundwater.
Types of Permeable Pavement
- Porous Asphalt. Porous asphalt looks very similar to traditional nonpervious asphalt, and uses the same equipment to mix and install. The permeability is created by reducing the amount of tar and removing the smallest particles from the asphalt mix, allowing water to pass freely through small airways and passages in the asphalt.
- Porous Concrete. Porous concrete also uses the same mixing and installation equipment as traditional concrete, although it looks noticeably rougher.
- Plastic Grid Systems. Plastic grids provide structural support and prevent erosion, and are filled with gravel or soil, usually planted with grass. Also known as geocells and reinforced turf, this type of surface is best suited for low traffic areas.
- Block Paving. Bricks, concrete blocks, and other interlocking pavers, generally set into a layer of small aggregate, are an attractive semi-permeable option, especially well-suited to low or moderate traffic areas such as walkways, residential driveways, and small parking lots.
- Other Materials. Easy, inexpensive do-it-yourself permeable pavement can be created in areas where code allows it with the use of gravel, mulch, dirt, or similar materials. However, these typically suffer from compaction that reduces the permeability over time, and are likely to have problems with mud and/or dust.
- Permeable Pavement
The main advantages to permeable pavement are cost savings compared to typical stormwater drainage systems, reduction of absorbed solar heat gain, and improved driving conditions.
- Pro Builder: Permeable Paving a Good Option for Green Homebuilding
One of the fastest growing approaches to green site development is permeable paving.
- Pavement Interactive: Permeable Pavements
Permeable pavements allow water to infiltrate through surfaces that would normally be impermeable, such as asphalt or concrete parking lots.
- Build It Green: Permeable Pavements
An overview of permeable pavement
- Permeable Paving Comparison (PDF)
An easy-to-understand comparison of concrete pavers and other pavement types.