(A) Regulations not retroactive. The regulations prescribed by this article shall not be construed to require the removal, lowering, or other changes or alteration of any structure or tree not conforming to the regulations as of the effective date of the ordinance from which this article is derived, or otherwise interfere with the continuance of any nonconforming use. Nothing herein contained shall require any change in the construction, alteration, or intended use of any structure, the construction or alteration of which was begun prior to the effective date of the ordinance from which this article is derived, and is diligently prosecuted.
(B) Marking and lighting. Notwithstanding subsection (A) above of this section, the owner of any nonconforming structure or tree is hereby required to permit the installation, operation, and maintenance thereon of such markers and lights as shall be deemed necessary by the administrative agency to indicate to the operators of aircraft in the vicinity of the airport the presence of such airport hazards. Such markers and lights shall be installed, operated, and maintained at the expense of the city.
(Prior Code, § 8-113) (Ord. 690, passed 1-5-1970)