The zoning district boundary lines are either streets, alleys, highway rights-of-way, railroad rights-of-way or waterways, lot lines, property lines, quarter section lines, half section lines or full section lines, unless otherwise indicated.

In unplatted areas or areas not subdivided into lots and blocks, whenever a district is parallel or adjacent to a railroad, street, or highway, the depth of such districts shall be the dimensions indicated, measured at right angles to the railroad, street, or highway.

Whenever a street, alley, highway, or other public thoroughfare, between two zoning districts, is officially vacated, the zoning district abutting each side of such street, alley, highway, or other public thoroughfare shall extend to the centerline of the vacated public thoroughfare.

Whenever the zoning district boundary line is uncertain, the board of adjustments shall determine the location of the boundary line.

Floodplain districts will be defined by the 100-year flood profile map. [Code 1975 § 6-5.0107.]