(1) Where the indicated boundaries on the Zone Map are approximately street or alley lines, the centerline of said street or alley shall be construed to be the zone boundary.

(2) Where the indicated boundaries are approximate lot lines, said lot lines shall be construed to be the zone boundary unless otherwise indicated.

(3) Where the indicated boundaries are approximately canals, water courses, or other clearly defined natural features, the center lines of such canals, water courses, or natural features shall be construed to be the zone boundaries unless otherwise indicated.

(4) In the absence of any street, land survey, lot, canal, water course, or other natural feature or measurement, the zone boundary shall be determined by the use of scale of measurement shown upon the Map.

(5) Where other uncertainty exists, the Planning Commission shall interpret the locations of zone boundaries upon said Zone Map.