The grading plan shall show contour lines at five-foot intervals where average slopes exceed fifteen percent (15%) and at two-foot intervals where slopes are less than fifteen percent (15%). Elevations are to be based on the sea level datum (USGS), if available. The approximate lot layout and the approximate dimensions shall be shown for each lot and each building site. Where pads are utilized or proposed for building sites, engineering data shall show the existing topography and the approximate finished grades, location and size of each building site and finished grade of streets prior to consideration of the final plat.
(1984 Code Sec. 151.103)