The initial boundaries of the floodplain supplemental district shall be established only after notice and public hearing before the planning and zoning commission and by approval of the city commission. Amendments to the floodplain districts shall be established in the same manner as amendments to any other zoning district as set forth in chapter 12 of this title including provisions for fees and public notice. Lands within the floodplain supplemental district shall be identified on the official zoning map by the suffix FD following the general zoning district designation. The boundaries of the floodplain supplemental district may be amended so as to maintain uniformity with the purposes of this title upon a finding that:
A. A flood control project of the federal, state, county or city government, or a private person, has substantially altered the boundaries of the floodway;
B. Flood data compiled subsequent to the enactment of the district indicates that the boundaries of the district should be adjusted; or
C. Proposed improvements such as berms, dikes, channel improvements or flood retention reservoirs which will substantially alter the boundaries of the floodway and the actual construction of said improvements has been assured by the submission and acceptance of bond. (Ord. 939, 11-14-2011)