A. 
Applicability. If these standards conform to  § 62.23(7)(h), Wis. Stats., they shall apply to all modifications or additions to any nonconforming use or structure and to the use of any structure or premises which was lawful before the passage of this chapter or any amendment thereto.
B. 
Lawful use. The existing lawful use of a structure or its accessory use which is not in conformity with the provisions of this chapter may continue subject to the following conditions:
(1) 
No modifications or additions to a nonconforming use or structure shall be permitted unless they comply with this chapter. The words "modification" and "addition" include, but are not limited to, any alteration, addition, modification, structural repair, rebuilding or replacement of any such existing use, structure or accessory structure or use. Ordinary maintenance repairs are not considered an extension, modification or addition; these include painting, decorating, paneling and the replacement of doors, windows and other nonstructural components and the maintenance, repair or replacement of existing private sewage or water supply systems or connections to public utilities. Ordinary maintenance repairs do not include any costs associated with the repair of a damaged structure. The construction of a deck that does not exceed 200 square feet and that is adjacent to the exterior wall of a principal structure is not an extension, modification or addition. The roof of the structure may extend over a portion of the deck in order to provide safe ingress and egress to the principal structure.
(2) 
If a nonconforming use or the use of a nonconforming structure is discontinued for 12 consecutive months, it is no longer permitted and any future use of the property, and any structure or building thereon, shall conform to the applicable requirements of this chapter.
(3) 
The municipality shall keep a record which lists all nonconforming uses and nonconforming structures, their present equalized assessed value, the cost of all modifications or additions which have been permitted, and the percentage of the structure's total current value those modifications represent.
(4) 
No modification or addition to any nonconforming structure or any structure with a nonconforming use which over the life of the structure would equal or exceed 50% of its present equalized assessed value shall be allowed unless the entire structure is permanently changed to a conforming structure with a conforming use in compliance with the applicable requirements of this chapter. Contiguous dry land access must be provided for residential and commercial uses in compliance with § 468-27A. The costs of elevating a nonconforming building or a building with a nonconforming use to the flood protection elevation are excluded from the 50% provisions of this subsection.
(a) 
Except as provided in Subsection B(4)(b) below, if any nonconforming structure or any structure with a nonconforming use is destroyed or is substantially damaged, it cannot be replaced, reconstructed or rebuilt unless the use and the structure meet the current requirements of this chapter. A structure is considered substantially damaged if the total cost to restore the structure to its predamaged condition equals or exceeds 50% of the structure's present equalized assessed value.
(b) 
For nonconforming buildings that are damaged or destroyed by a non-flood disaster, the repair or reconstruction of any such nonconforming building may be permitted in order to restore it after the non-flood disaster, provided that the nonconforming building will meet all of the minimum requirements under applicable FEMA regulations (44 CFR Part 60), or the regulations promulgated thereunder.
(5) 
A nonconforming historic structure may be altered if the alteration will not preclude the structure's continued designation as a historic structure, the alteration will comply with § 468-23A, flood-resistant materials are used, and construction practices and floodproofing methods that comply with § 468-41 are used.
A. 
Modifications or additions.
(1) 
No modification or addition shall be allowed to any nonconforming structure or any structure with a nonconforming use in a floodway area, unless such modification or addition:
(a) 
Has been granted a permit or variance which meets all requirements of this chapter.
(b) 
Meets the requirements of § 468-31.
(c) 
Will not increase the obstruction to flood flows or regional flood height.
(2) 
Any addition to the existing structure shall be floodproofed, pursuant to § 468-41, by means other than the use of fill, to the flood protection elevation.
(3) 
If any part of the foundation below the flood protection elevation is enclosed, the following standards shall apply:
(a) 
The enclosed area shall be designed by a registered architect or engineer to allow for the efficient entry and exit of floodwaters without human intervention. A minimum of two openings must be provided with a minimum net area of at least one square inch for every one square foot of the enclosed area. The lowest part of the opening can be no more than 12 inches above the adjacent grade;
(b) 
The parts of the foundation located below the flood protection elevation must be constructed of flood-resistant materials;
(c) 
Mechanical and utility equipment must be elevated or floodproofed to or above the flood protection elevation; and
(d) 
The use must be limited to parking or limited storage.
B. 
No new on-site sewage disposal system, or addition to an existing on-site sewage disposal system, except where an addition has been ordered by a government agency to correct a hazard to public health, shall be allowed in a floodway area. Any replacement, repair or maintenance of an existing on-site sewage disposal system in a floodway area shall meet the applicable requirements of all municipal ordinances and Ch. SPS 383, Wis. Adm. Code.
C. 
No new well or modification to an existing well used to obtain potable water shall be allowed in a floodway area. Any replacement, repair or maintenance of an existing well in a floodway area shall meet the applicable requirements of all municipal ordinances and Chs. NR 811 and NR 812, Wis. Adm. Code.
A. 
No modification or addition shall be allowed to any nonconforming structure or any structure with a nonconforming use unless such modification or addition has been granted a permit or variance by the municipality, and the modification or addition shall be placed on fill or floodproofed to the flood protection elevation in compliance with the standards for that particular use in §§ 468-27 and 468-41, except where Subsection B below is applicable.
B. 
Where compliance with the provisions of Subsection A would result in unnecessary hardship and only where the structure will not be used for human habitation or be associated with a high flood damage potential, the Zoning Board of Appeals, using the procedures established in § 468-39, may grant a variance from those provisions of Subsection A for modifications or additions, using the criteria listed below. Modifications or additions which are protected to elevations lower than the flood protection elevation may be permitted if:
(1) 
No floor is allowed below the regional flood elevation for residential or commercial structures;
(2) 
Human lives are not endangered;
(3) 
Public facilities, such as water or sewer, will not be installed;
(4) 
Flood depths will not exceed two feet;
(5) 
Flood velocities will not exceed two feet per second; and
(6) 
The structure will not be used for storage of materials as described in § 468-27E.
C. 
If neither the provisions of Subsection A or B above can be met, one addition to an existing room in a nonconforming building or a building with a nonconforming use may be allowed in the flood-fringe, if the addition:
(1) 
Meets all other regulations and will be granted by permit or variance;
(2) 
Does not exceed 60 square feet in area; and
(3) 
In combination with other previous modifications or additions to the building, does not equal or exceed 50% of the present equalized assessed value of the building.
D. 
All new private sewage disposal systems, or addition to, replacement, repair or maintenance of a private sewage disposal system, shall meet all the applicable provisions of all local ordinances and Ch. SPS 383, Wis. Adm. Code.
E. 
All new wells, or addition to, replacement, repair or maintenance of a well, shall meet the applicable provisions of this chapter and Chs. NR 811 and NR 812, Wis. Adm. Code.
No modifications or additions shall be allowed to any nonconforming structure in a flood storage area unless the standards outlined in § 468-30C are met.