This chapter shall take effect upon publication after final passage according to law.

All ordinances and parts of ordinances inconsistent with the provisions of this chapter are hereby repealed to the extent of the inconsistency.

If any section or provision of this chapter shall be held invalid in any court, that adjudication shall not affect any other section or provision of this chapter except insofar as the section or portion adjudicated to be invalid shall be inseparable from the remainder thereof.

If the owners of 50% of the area of the land in a district or continuous part thereof not less than one block or 10% of its total area shall present to the Mayor and Council a petition for the amendment, change, modification or repeal of any of the regulations, limitations or restrictions of this chapter or the boundaries of the district accompanied by a map showing the area of the district or the part thereof and the land owned by all entitled by law to protest the prepared amendment, change, modification or repeal, the Mayor and Council shall act thereon within 90 days.