The filling of lands where the existing ground elevation is less than the flood base elevation shall be permitted provided:
(a) That the material is obtained from adjacent areas lying below the flood base elevation or
(b) That the fill material obtained elsewhere is offset by the removal of an equivalent volume of material obtained in the immediate vicinity of the building site from elevations lower than the flood base elevation. If fill or any type of construction which would displace flood waters is placed within the flood plain, a flood reservoir shall be constructed (the bottom of which shall not be lower than the bottom of the adjacent water course) equal in volume to the volume of such fill or construction deposited below the flood base elevation. Each such flood reservoir shall have adequate provision for drainage to the waterway. The deepening of a water course is permitted, but the material removed must not be deposited below the flood base elevation, except in accordance with (b) above. The placement of fill material shall parallel the water course. (M.C. 1963, § 22.901; Ord. No. 0-64-29)