13-1-4: NONCONFORMING STRUCTURES AND USES:
The lawful use of a building, structure or property which existed at the time this title, or an applicable amendment to this title, took effect and which is not in conformity with the provisions of this title, including the routine maintenance of such a building or structure, may be continued, subject to the following conditions:
   A.   The shoreland-wetland provisions of this title authorized by section 62.231, Wisconsin statutes, shall not limit the repair, reconstruction, renovation, remodeling or expansion of a nonconforming structure in existence on the effective date hereof, or of any environmental control facility in existence on May 7, 1982, related to such a structure. All other modifications to nonconforming structures are subject to section 62.23(7)(h), Wisconsin statutes, which limits total lifetime structural repairs and alterations to fifty percent (50%) of current fair market value.
   B.   If a nonconforming use or the use of a nonconforming structure is discontinued for twelve (12) consecutive months, any future use of the building, structure or property shall conform to this title.
   C.   Any legal nonconforming use of property which does not involve the use of a structure and which existed at the time of the adoption or subsequent amendment of this title adopted under section 61.351 or 62.231, Wisconsin statutes, may be continued although such use does not conform with the provisions of this title. However, such nonconforming use may not be extended.
   D.   The maintenance and repair of nonconforming boathouses which are located below the ordinary high water mark of any navigable waters shall comply with the requirements of section 30.121, Wisconsin statutes.
   E.   Uses which are nuisances under common law shall not be permitted to continue as nonconforming uses. (1975 Code Ch.23 §IV)