(A) This chapter may be amended whenever the public necessity and convenience and the general welfare require such amendment by following the procedure specified in this section.
(B) An amendment may be initiated by the City Council or the Planning Commission, or by the verified petition of not less than 50% of the property owners within 300 feet of the proposed change. An amendment not initiated by the Planning Commission shall be referred to the Commission for study and report and may not be acted upon by the governing body until it has received the recommendation of the Planning Commission or until 60 days have elapsed from the date of reference of the amendment without a report by the Planning Commission.
(C) Before any amendment is adopted, the Planning Commission shall hold at least one public hearing thereon after a notice of the hearing has been published in the official newspaper at least ten days before the hearing. When an amendment involves changes in district boundaries affecting an area of five acres or less, a similar notice shall be mailed at least ten days before the day of the hearing to each owner of affected property and property to which the amendment relates. Following the hearing, the Planning Commission shall make a report of its findings and recommendations on the proposed amendment and shall file a copy with the City Clerk within ten days of the meeting at which the date of the hearing was set. Failure of the Planning Commission so to report shall be deemed to be approval by the Commission of the proposed amendment.
(D) Upon the filing of such report or upon the expiration of such ten days as aforesaid, the City Council shall hold such public hearing upon the amendment as it deems advisable. After the conclusion of the hearing, if any, the Council may adopt the amendment or any part thereof in such form as it deems advisable. The amendment shall be effective only if two-thirds of all the members of the Council concur in its passage.
(E) (1) The floodplain designation on the official zoning map shall not be removed from floodplain areas unless it can be shown that the designation is in error or that the area has been filled to or above the elevation of the regional flood and is contiguous to land outside the floodplain. Special exceptions to this rule may be permitted by the Commissioner of Natural Resources if he or she determines that, through other measures, lands are adequately protected for the intended use.
(2) All amendments to this chapter relating to uses in the Floodplain District (F-1), in Part VIII of this chapter, including amendments of the official zoning map, must be submitted to and approved by the Commissioner of Natural Resources prior to adoption. Changes in the official zoning map also require prior approval by the Federal Insurance Administration for use in the Floodplain District (F-1), Part VIII of this chapter.