Wherever building sites are or may be subject to flooding, the lot shall be sloped one foot (1') to fifteen feet (15') around each building and shall be filled up to about six inches (6") or one foot (1') below the minimum sill elevation for building openings and maintained at an elevation one foot (1') above the flood base elevation for the site at a minimum distance of fifteen feet (15') from the building. On building sites located on higher ground, the surface of each lot shall be graded so as to slope away from each building and provide a shallow swale between adjoining properties. (M.C. 1963, § 22.903(c); Ord. No. 0-64-29; renumbered Ord. 0-77-60, 9-19-77)