Definitions for "Impervious Surface"
An area covered with solid material or that is compacted to the point where water can not infiltrate underlying soils (e.g. parking lots, roads, houses, patios, swimming pools, tennis courts, etc.). Stormwater runoff velocity and volume can increase in areas covered by impervious surfaces.
Waterproof ground cover that does not allow for infiltration of water (e.g., roofs, parking lots, roads) and which increases the volume and speed of runoff after a rainfall.
Hard, non-porous surfaces such as roads, parking lots, and rooftops that prevent precipitation from soaking into the ground, thus increasing surface runoff.