201.07 PERMITS.
Nothing contained in any of the foregoing exceptions shall be construed as permitting or intending to permit any construction or alteration of any structure, or growth of any tree in excess of any of the height limits established by this chapter.
1.   Existing Use. No permit shall be granted that would allow the establishment or creation of an obstruction or permit a nonconforming use, structure, or tree to become a greater hazard to air navigation, than it was on the effective date of this chapter or any amendment thereto or than it is when the application for a permit is made.
2.   Nonconforming Uses Abandoned or Destroyed. Whenever the Community Development Director determines that a nonconforming structure is abandoned for one year or destroyed, by any means, to the extent of more than sixty percent of the replacement cost, such structure shall not be rebuilt, restored, or reoccupied for any purpose unless it shall thereafter conform to all regulations of this chapter.
3.   Variances. Any person desiring to erect or increase the height of any structure, or permit the growth of any tree, or use property not in accordance with the regulations prescribed in this chapter, may apply to the Airport Board Of Adjustment for a variance from such regulations. The application for variance shall be accompanied by a determination from the Federal Aviation Administration as to the affect of the proposal on the operation of air navigation facilities and the safe, efficient use of navigable airspace. Such variances shall be allowed where it is duly found that a literal application or enforcement of the regulations will result in practical difficulty or unnecessary hardship, and relief granted will not be contrary to the public interest, will not create a hazard to air navigation, will do substantial justice, and will be in accordance with the spirit of this chapter. Additionally, no application for variance to the requirements of this chapter may be considered by the Board of Adjustment unless a copy of the application has been furnished to the Airport Manager for advice as to the aeronautical effects of the variance. If the Airport Manager does not respond to the application by the meeting, the Airport Board of Adjustment may act on its own to grant or deny said application.
4.   Obstruction Marking and Lighting. Any variance granted may, if such action is deemed advisable to effectuate the purpose of this chapter and is reasonable in the circumstances, be so conditioned as to require the owner of the structure or tree in question to install, operate and maintain, at the owner’s expense, such markings and lights as may be necessary. If deemed proper by the Airport Board of Adjustment, this condition may be modified to require the owner to permit the Polk County Aviation Authority, at its own expense, to install, operate and maintain the necessary markings and lights.