A. The regulations prescribed herein are not retroactive and shall not be construed to require the removal of any tree, or the reconstruction or alteration, or the discontinuation of any use of any structure made nonconforming by the adoption of this chapter.
B. Nothing contained herein shall require any change in the construction or alteration, or the intended use of any structure, the construction or alteration of which was begun prior to the effective date hereof, and which was conforming prior to the adoption of this chapter, and is completed within one year thereafter.
C. No preexisting nonconforming structure, use, or tree shall be rebuilt, altered, allowed to grow higher, or be replanted, so as to constitute a greater airport hazard than it was at the time that these regulations were adopted.
D. Whenever the building official or zoning administrator determines that a nonconforming structure has been abandoned, torn down, physically deteriorated, damaged, or decayed, to such an extent that its value is no greater than fifty percent (50%) of the average value of the structure and the land over the preceding ten (10) years, no building permit or occupancy permit shall be issued that would allow such structure to exceed the applicable height and use provisions of this chapter. Any tree so damaged or destroyed shall be subject to the provisions of subsection 14-6-5G6 of this chapter.
E. Not withstanding the previous provisions of this section the owner of any preexisting nonconforming structure or tree shall be required to permit the installation, operation, or maintenance thereon of any markers and/or lights as shall be deemed necessary by the city or county to indicate to the operators of aircraft, the presence of such structure or tree. (Ord. 02-4055, 12-10-2002)