10-1-1: CITY DIVIDED INTO DISTRICTS:
For the purpose of regulating, classifying and restricting the location of trades, industries and enterprises, and the location of buildings designed, erected or altered for specified uses, and limiting the height and size of such buildings, and the use of areas in this municipality, and regulating and determining the area of the yards and other open spaces surrounding buildings hereafter erected, and preventing additions to, and alterations or remodeling of existing buildings or structures in such manner as to avoid the restrictions and limitations in this title contained, the city is hereby divided into the following districts:
   A Residence district
   B Residence district
   C Commercial district
   D Industrial district
   E Industrial district
(1975 Code § 10-1-1)