In order to regulate and restrict the height, number of stories and size of buildings and other structures, the percentage of lot that may be occupied, the size of yards, courts and other open spaces, the density of population, and the location and use of the buildings, structures and lands for trade, industry, residence or other purposes, the city is divided into districts of which there shall be four in number known as:

   A.   "A" Single-family dwelling district;

   B.   "B" Multiple dwelling district;

   C.   "C" Commercial district;

   D.   "D" Industrial district (Prior code § 11-2-1)

   The boundaries of the districts are shown upon the map which is made a part of this chapter and is designated as the "district map." The district map and all the notations, references and other information shown thereon are part of this chapter and have the same force and effect as if the district map and all the notations, references and other information shown thereon were all fully set forth or described in this section, which district map is properly attested and is on file with the clerk of the city. (Prior code § 11-2-2)

   Where uncertainty exists with respect to the boundaries of the various districts as shown on the district map accompanying and made a part of this chapter, the following rules apply:

   A.   The district boundaries are either streets or alleys unless otherwise shown, and where the districts designated on the district map accompanying and made a part of this chapter are bounded approximately by street or alley lines, the street or alley shall be construed to be the boundary of the district.

   B.   Where the district boundaries are not otherwise indicated, and where the property has been or may hereinafter be divided into blocks and lots, the district boundaries shall be construed to be the lot lines, and where the districts designated on the district map accompanying and made a part of this chapter are bounded approximately by lot lines, the lot lines shall be construed to be the boundary of the districts unless the boundaries are otherwise indicated on the district map.

   C.   In unsubdivided property, the district boundary lines on the district map accompanying and made a part of this chapter shall be determined by use of the scale appearing on the district map. (Prior code § 11-3-11)

   All territory proposed for annexation shall be studied by the Planning and Zoning Commission. If the Planning and Zoning Commission recommends approval of the annexation request, a second recommendation shall be prepared to assign the proposed territory a zoning district in conformance with the comprehensive plan. The City Commission shall consider both the annexation request and zoning recommendation concurrently at the next regularly scheduled meeting. (Ord. 513, 2013; Prior code § 11-2-3)

   Whenever any street, alley or other public way is vacated by official action of the city commission, the zoning districts adjoining each side of such street, alley or public way shall be automatically extended to the center of such vacation and all area included in the vacation shall then and thenceforth be subject to all appropriate regulations of the extended districts. (Prior code § 11-2-4)