“Impermeable surface” means a nonvegetated surface area which either prevents or retards the entry of water into the soil mantle as under natural conditions prior to development, and/or causes water to run off the surface in greater quantities or at an increased rate of flow from the flow present under natural conditions prior to development. Common impermeable surfaces include, but are not limited to, roof tops, walkways, patios, driveways, parking lots or storage areas, concrete or asphalt paving, gravel roads with compacted sub-grade, packed earthen materials, and oiled, macadam or other surfaces which similarly impede the natural infiltration of stormwater. Open, uncovered retention/detention facilities and tidelands shall not be considered as impermeable surfaces for the purposes of determining whether the thresholds for application of stormwater minimum requirements are exceeded but shall be considered impermeable surfaces for purposes of runoff modeling. (Ord. 1347 § 16, 2016; Ord. 1278 § 4, 2013; Ord. 863 § 2, 2001; Ord. 573 § 2, 1990).