And finally for the developer or engineer, it makes possible maximum land use for parking lots, roads, and structures and may reduce the size of retention areas. Storm drains may be eliminated and some curbing as well. For watershed and estuary areas it is an environmental tool to keep these waters clean. These are dollars and sense issues. Test borings will establish whether soil will support subbase and pervious pavement.
Engineering is an important part of successful pervious pavement.
The compacted base must be moist prior to the placement of paving material, but no puddles of free standing water can be tolerated. Pervious mixtures must employ high quality control. Almost all fine aggregate is eliminated from the mix to provide the necessary voids to allow the penetration of water. The amount and timing of the addition of water to the mix is critical. Too much water will carry the cement slurry to the base of the pavement creating a barrier that prevents water from passing into the subbase and substrate.