Low impact development or (LID) is an approach to development of land that works to preserve existing natural conditions as much as possible in an effort to minimize imperviousness while retaining functional site drainage of stormwater.  Popular LID practices include the use of rain gardens, rain barrels, vegetated rooftops, and permeable pavements.  The design of a stormwater control to satisfy low impact development requirements should be performed on a site-specific case-by-case basis.  Permeable pavement is a useful LID as substitute for traditional parking lot surfaces or driveways to allow infiltration and reduce the effective impervious area.  Installation of permeable pavement may provide enough water capacity to decrease the need for retention ponds, swales, and other runoff containment controls.  Base layers and sub base layers are installed prior to the permeable pavement to provide the appropriate aggregate bottom drainage layer.  One common concern with permeable pavement is the prevention of clogging which decreases the infiltration ability.  First, attention should be given to nearby runoff sources to determine if there is potential for unwanted sediment from loose soil or mulch beds that can be pushed onto the pavers after a heavy rainfall.  Pavements should be inspected after heavy rainfalls to determine if any excess sediment has tracked onto the surface.  Following inspections, the permeable pavements should be cleaned if necessary to remove the sediment from the voids between pavers.  Use of vacuum trucks designed for pavement cleaning  with adjustable vacuum suction is the preferred method to clean the pavers during dry conditions.  Vacuum truck sweep broom attachments or water spray attachments should not be used as these methods may push debris farther down into the aggregate layers beneath the permeable pavement.