All properties, depending on the township and zoning, will have a limit on the amount of impervious surfaces that can exist on the lot at a time. This can be very frustrating for some as this percentage can be set low, limiting what they can do. The once expansive addition with a patio now has to be reduced in size or cannot be built at all due to the limitations placed on the property. To work around this issue, eco pavers and paving have been incorporated into designs in an effort to reduce the impervious coverage.
“Eco” pavers/paving work by allowing water to percolate through the paving or paver in question instead of just running off into the lawn or storm inlets and are designed in a way that is similar to a underground infiltration bed.
These systems can be designed in a couple of ways, depending on the needs of that particular project. One such way would be similar to a stone infiltration bed. The walkway would be designed to infiltrate the runoff from the pavers or paving directly beneath it and into an uncompact subgrade, exactly how a normal infiltration bed would. This method would also require infiltration testing to ensure that the soil has the capability to infiltrate the runoff into the ground. An alternate method would be to run a perforated collector pipe under the Eco Pavers to convey runoff to a nearby bed or basin, which would then eliminate the need for testing under the pavers while still allowing water to infiltrate into the soil.
After installation, these eco pavers will need to be maintained in order to continue to act as a permeable surface. Porous pavement, for example, requires the use of a Vacuum Sweep a couple times a year to ensure that the pavement is free from any sediment that would otherwise clog the system. This kind of paving can also never be sealed and must be repaved with porous materials to function properly.
While this might seem like a good idea to add to a project to help reduce the impervious coverage on the site it does have its downsides. These systems will need to be maintained by the owner to ensure that they continue to function as designed & not all townships approve of the use of Eco pavers as a way to reduce coverage on a property. So it’s always a good idea to check with the township to make sure that they will approve of the design.