The following words and phrases shall be defined as follows:
DEVELOPED PARCEL: Any parcel that has been altered from its natural condition by grading, filling or the construction of improvements or other impervious surfaces.
EQUIVALENT RESIDENTIAL UNIT (ERU): The average amount of impervious surface, expressed in square feet, on developed single-family residential parcels in the City of Cedar Hills.
IMPERVIOUS SURFACE: Any hard surface, other than the natural surface, that prevents or retards the absorption of water into the soil, or that causes water to run off the surface in greater quantities or at a greater rate of flow than the natural surface. (Ord. 10-6-98A, 10-6-1998; amd. Ord. 9-20-2011A, 9-20-2011)