For the purpose of this ordinance the following zones are hereby established:

The boundaries for the zones listed in this ordinance are indicated on the zoning map which is hereby adopted by reference. The boundaries shall be modified in accordance with the provisions of the Land Use Plan and with zoning map amendments which shall be adopted by reference.

Unless otherwise specified, zone boundaries are section lines, subdivision lines, lot lines, center lines of street or railroad rights-of-way, or such lines extended.

Areas annexed to the city shall be zoned at the time of annexation, and shall relate to the provisions of the Land Use Plan and state statutes.