Where uncertainty exists as to the boundaries of districts as shown on the official zoning map, the following rules shall apply:

   1.   Boundaries and Centerlines. Boundaries indicated as approximately following the centerlines of streets, highways or alleys shall be construed to follow such centerlines.

   2.   Boundaries and Platted Lot Lines. Boundaries indicated as approximately following platted lot lines shall be construed as following such lot lines.

   3.   Boundaries and Township Lines and Section Lines. Boundaries indicated as approximately following township lines or section lines shall be construed as following township lines or section lines.

   4.   Boundaries and Railroad Lines. Boundaries indicated as following railroad lines shall be construed to be midway between the main tracks.

   5.   Boundaries and Shore Lines. Boundaries indicated as following shore lines shall be construed to follow such shore lines, and in the event of change in the shore line, shall be construed as moving with the actual shore line; boundaries indicated as approximately following the centerlines of streams or other bodies of water shall be construed to follow such centerlines.

   6.   Boundaries That are Parallels or Extensions. Boundaries indicated as parallel to or extensions of features indicated in subsections 1 through 5 above shall be so construed. Distances not specifically indicated on the official zoning map shall be determined by the scale of the map.

   7.   Board Interpretation of District Boundaries. Where physical or cultural features existing on the ground are at variance with those shown on the official zoning map, or in other circumstances not covered by subsections 1 through 6 above, the Board shall interpret the district boundaries.

   8.   Boundaries and Lots of Record. Where a district boundary divides a lot of record that was in single ownership at the time of the effective date of these regulations, the Board may permit, as a special exception or variance, the extension of the regulations for either portion of the lot not to exceed 30 feet beyond the district boundary.