(A) The boundaries of these districts are hereby established as shown on the zoning map, which is a part of this chapter and which is on file in the office of the City Clerk.
(B) Where uncertainty exists with respect to the boundaries of the districts as shown on the zoning map, the following rules shall apply.
(1) Where district boundary lines are indicated as approximately following the center lines of streets, alleys, highways, railroads or railroad right-of-way lines or the lines extended, the center lines or railroad right-of-way lines or the lines extended shall be construed to be the boundaries.
(2) Where a district boundary line is indicated as approximately following the corporate limits line of the city, the corporate limits line shall be construed to be the boundary line.
(3) Where a district boundary line is indicated as approximately following a stream bed, the stream bed shall be construed to be the district boundary line.
(4) Where a district boundary line is indicated as approximately following a rear or side lot line or the line extended, the rear or side lot line or the line extended shall be construed to be the boundary line.
(5) Where district boundary lines are so indicated that they are approximately parallel to the right-of-way lines of streets, the district boundary lines, unless otherwise specifically indicated, shall be construed as being parallel thereto and at a distance of 150 feet from the right-of-way lines of the street.
(6) Where a district boundary line as appearing on the zoning map divides a lot in single ownership at the time of the enactment of subsequent amendment of this chapter or at the time the area in which the lot is located is annexed to the city, if the portions of the lot lying in both zoning districts have street frontage, the requirements to the district in which the portion of the lot with the greatest street frontage lies shall apply to the entire lot.
(a) If the lot is divided by the district boundary line so that the portion of the lot in one zoning district has street frontage and the portion of the lot in the other zoning district does not have street frontage, the requirements of the district in which the portion of the lot having street frontage lines shall apply to the entire lot.
(b) In the event that a double frontage lot is divided by a district boundary line so that the portion of the lot fronting on one street is in a different district from the portion of the lot fronting on the other street, the requirements of the district in which each portion of the lot is located shall apply to that portion.
(c) In the event one or both portions of a double frontage lot divided by a zoning district boundary line are too small to meet the area and yard requirements of the zoning districts in which they are located, the Board of Zoning Adjustment may allow the requirements of one district to apply to the entire lot.
(d) The Board shall make every effort to ensure that the intent and spirit of this chapter are carried out and the public welfare protected by its decision. Regardless of whether it lies in one or two zoning districts, a double frontage lot must meet the front yard requirements on both of the streets upon which it abuts.
(7) In any case not covered by the above rules or where there is disagreement over the interpretation of the above rules, the exact location of a district boundary line shall be determined by the Board of Zoning Adjustment.
(2000 Code, App. B, § 42)