The existing lawful use of a structure, building or property, or its accessory use, which is not in conformity with the provisions of this Chapter may be continued subject to the following conditions:
(a) Notwithstanding Section 62.23(7)(h), Wis. Stats., the repair, reconstruction, renovation, remodeling or expansion of a legal nonconforming structure in existence at the time of adoption or subsequent amendment of this Chapter adopted under Section 62.231, Wis. Stats., or of an environmental control facility in existence on May 7, 1982, related to that structure, is permitted under Section 62.231(5), Wis. Stats. Section 62.23(7)(h), Wis. Stats., applies to any environmental control facility that was not in existence on May 7, 1982, but was in existence on the effective date of this Chapter or amendment.
(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 the appropriate provisions of this Chapter.
(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 Chapter adopted under Sections 62.231 or 61.351, Wis. Stats., may be continued although such use does not conform with the provisions of this Chapter. 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, Wis. Stats.
(e) Uses which are nuisances under common law shall not be permitted to continue as nonconforming uses.