The boundaries of the zones designated in this chapter shall be established and clearly marked upon that certain map identified by the approving signatures of the city council, marked and designated as the "zoning map", which map is now on file in the office of the city clerk. The map has been heretofore examined in detail by the city council and is adopted as a part of this title, but this title and the map shall be subject to change, from time to time, as may be determined by the city council, following procedures provided by law. The current map and each subsequent update shall be signed and dated by the city council. Unless otherwise designated on the zoning district map, district boundary lines are lot lines; the centerlines of streets, alleys, railroad rights of way, or such lines as extended section lines; municipal corporate lines; centerlines of streambeds; or other lines drawn to scale on the zoning district map. (Ord. 184, 2-10-2011)