(A) Applicability.
(1) The standards in this section shall apply to all uses and buildings that do not conform to the provisions contained within a floodplain zoning ordinance or with Wisconsin Statutes § 815.3.300, and §§ NR 116.12-14, Wis. Adm. Code and 44 CFR 59-72. These standards 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. A party asserting the existence of a lawfully established nonconforming use or structure has the burden of proving that the use or structure was compliant with the floodplain zoning ordinance in effect at the time the use or structure was created.
(2) As permit applications are received for additions, modifications, or substantial improvements to nonconforming buildings in the floodplain, municipalities shall develop a list of those nonconforming buildings, their present equalized assessed value, and a list of the costs of those activities associated with changes to those buildings.
(B) 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) (a) 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. Maintenance is not considered a modification; this includes painting, decorating, paneling and other nonstructural components and the maintenance, repair or replacement of existing private sewage or water supply systems or connections to public utilities. Any
costs associated with the repair of a damaged structure are not considered maintenance.
(b) 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 § 15.3.033(A). The costs of elevating the lowest floor of a nonconforming building or a building with a nonconforming use to the flood protection elevation are excluded from the 50% provisions of this division (B)(4).
(5) No maintenance on a per event basis to any nonconforming structure or any structure with a nonconforming use, the cost of which 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 § 15.3.033(A). Maintenance to any nonconforming structure, which does not exceed 50% of its present equalized assessed value on a per event basis, does not count against the cumulative calculations over the life of the structure for substantial improvement calculations.
(6) If on a per event basis the total value of the work being done under divisions (B)(4) and (B)(5) above equals or exceeds 50% of the present equalized assessed value, the work shall not be permitted 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 § 15.3.033(A).
(7) Except as provided in division (B)(8) 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 ordinance requirements. A structure is considered substantially damaged if the total cost to restore the structure to its pre-damaged condition equals or exceeds 50% of the structure's present equalized assessed value.
(8) For nonconforming buildings that are substantially damaged or destroyed by a nonflood disaster, the repair or reconstruction of any such nonconforming building shall be permitted to restore it to the size and use in effect prior to the damage event, provided that the following minimum requirements are met, and all required permits have been granted prior to the start of construction:
(a) Residential structures:
1. Shall have the lowest floor, including basement, elevated to or above the base flood elevation using fill, pilings, columns, posts, or
perimeter walls. Perimeter walls must meet the requirements of § 15.3.065(B).
2. Shall be anchored to prevent flotation, collapse, or lateral movement of the structure resulting from hydrodynamic and hydrostatic loads, including the effects of buoyancy, and shall be constructed with methods and materials resistant to flood damage.
3. Shall be constructed with electrical, heating, ventilation, plumbing and air conditioning equipment and other service facilities that are designed and/or elevated so as to prevent water from entering or accumulating within the components during conditions of flooding.
4. In A zones, obtain, review, and utilize any flood data available from a federal, state or other source.
5. In AO zones with no elevations specified, shall have the lowest floor, including basement, meet the standards in § 15.3.044.
6. In AO zones, shall have adequate drainage paths around structures on slopes to guide floodwaters around and away from the structure.
(b) Nonresidential structures:
1. Shall meet the requirements of divisions (B)(8)(a)1. through 6. above.
2. Shall either have the lowest floor, including basement, elevated to or above the regional flood elevation; or, together with attendant utility and sanitary facilities, shall meet the standards in § 15.33.065(A) or (B).
3. In AO Zones with no elevations specified, shall have the lowest floor, including basement, meet the standards in § 15.3.044.
(C) A nonconforming historic structure may be altered if the alteration does not preclude the structure's continued designation as a historic structure, the alteration will comply with § 15.3.023(A), flood resistant materials are used, and construction practices and floodproofing methods that comply with § 15.3.065 are used. Repair or rehabilitation of historic structures shall be exempt from the development standards of § 15.3.051(B)(8)(a) if it is determined that the proposed repair or rehabilitation will not preclude the structure's continued designation as a historic structure and is the minimum necessary to preserve the historic character and design of the structure.
(D) Notwithstanding anything in this chapter to the contrary, modifications, additions, maintenance, and repairs to a nonconforming building shall not be prohibited based on cost and the building's nonconforming use shall be permitted to continue if:
(1) Any living quarters in the nonconforming building are elevated to be at or above the flood protection elevation.
(2) The lowest floor of the nonconforming building, including the basement, is elevated to or above the regional flood elevation.
(4) If the nonconforming building is in the floodway, the building is permanently changed to conform to the applicable requirements of §§ 15.3.023(A), 15.3.023(B)(2) through (B)(5), 15.3.023(C), 15.3.023(D), and 15.3.052. Any development that adds additional fill or creates an encroachment in the floodplain from beyond the original nonconforming structure's 3-D building envelope must determine the floodway in accordance with § 15.3.045. If the encroachment is in the floodway, it must meet the standards in § 15.3.023(D).
(6) Repair or reconstruction of nonconforming structures and substantial improvements of residential buildings in zones Al-30, AE, and AH must have the lowest floor (including basement) elevated to or above the base flood elevation.
(7) Repair or reconstruction of nonconforming structures and substantial improvements of nonresidential buildings in zones A1-30, AE, and AH must have the lowest floor (including basement) elevated to or above the base flood elevation, or (together with attendant utility and sanitary facilities) be designed so that below the base flood elevation the building is watertight with walls substantially impermeable to the passage of water and with structural components capable of resisting hydrostatic and hydrodynamic loads and effects of buoyancy:
(a) Where a non-residential structure is intended to be made watertight below the base flood elevation, a registered professional engineer or architect must develop and/or review structural design, specifications, and plans for the construction, and must certify that the design and methods of construction are in accordance with accepted standards of practice for meeting the provisions of division (D)(7) above.
(b) The community must maintain a record of such certification including the specific elevation to which each such structure is floodproofed.
(8) Fully enclosed areas below the lowest floor of repair or reconstruction of nonconforming structures and substantial improvements in zones A1-30, AE, and AH that are usable solely for parking of vehicles, building access, or storage, must be designed to adequately equalize hydrostatic forces on exterior walls by allowing for the entry and exit of floodwaters. Subsequent improvements to repaired or reconstructed nonconforming structures must not increase the degree of their nonconformity. Designs for meeting this requirement must either be certified by a registered professional engineer or architect, or meet the following criteria:
(a) A minimum of 2 openings into each enclosed area must be located below the base flood elevation and provide a total net area of not less than one square inch for every square foot of enclosed area.
(b) The bottom of all openings must be no higher than one foot above the adjacent grade.
(c) Openings may be equipped with screens, louvers, valves, or other coverings if they permit the automatic entry and exit of floodwaters.
(9) Manufactured homes that are placed or substantially improved within zones A1-30, AE, and AH outside of a manufactured home park or subdivision, in a new manufactured home park or subdivision, in an expansion to an existing manufactured home park or subdivision, or in an existing manufactured home park or subdivision on which a manufactured home has incurred substantial damage as a result of flood, must be elevated on a permanent foundation such that the lowest floor of the manufactured home is at or above the base flood elevation, and be securely anchored to an adequately anchored foundation system to resist flotation, collapse, and lateral movement;
(10) Manufactured homes that are placed or substantially improved within zones Al-30, AE, and AH on existing sites in an existing manufactured home park that is not undergoing expansion and on which a manufactured home has not incurred substantial damage as a result of flood must be elevated so that either the lowest floor of the manufactured home is at or above the base flood elevation, or the manufactured home chassis is supported by reinforced piers or other foundation elements of at least equivalent strength that are no less than 36 inches in height above grade, and be securely anchored to an adequately anchored foundation system to resist flotation, collapse, and lateral movement;
(11) Recreational vehicles placed on sites within zones A1-30, AH, and AE must either:
(a) Be on site for fewer than 180 consecutive days; or
(b) Be fully licensed and ready for highway use (a recreational vehicle is ready for highway use if it is on its wheels or jacking system, is attached to the site only by quick disconnect type utilities and security devices, and has no permanently attached additions); or
(c) Meet the elevation and anchoring requirements for manufactured homes in division (D)(9) above.
(12) In a regulatory floodway that has been delineated on the FIRM in zone A1-30 or AE, encroachments, including repair or reconstruction of nonconforming structures, substantial improvement, or other development (including fill) must be prohibited unless it has been demonstrated through hydrologic and hydraulic analyses performed in accordance with standard engineering practice that the proposed encroachment will not result in any increase in flood levels within the community during the occurrence of the base flood discharge. Subsequent improvements to repair or reconstructed nonconforming structures must not increase the degree of their nonconformity.
(13) In zone A, the community must obtain, review, and reasonably utilize any base flood elevation and floodway data available from a federal, state, or other source as criteria for requiring repair or reconstruction of nonconforming structures, substantial improvement, and other development to meet divisions (D)(6) through (12) (inclusive) above. Any development that adds additional fill or creates an encroachment in the floodplain from beyond the original nonconforming structure's 3-D building envelope must determine the floodway in accordance with § 15.3.045. If the encroachment is in the floodway, it must meet the standards in § 15.3.023(D). Subsequent improvements to repair or reconstructed nonconforming structures must not increase the degree of their nonconformity.
(14) In zones A1-30 or AE where a regulatory floodway has not been delineated on the FIRM, repair or reconstruction of nonconforming structures, substantial improvement, or any development that adds additional fill or creates an encroachment in the floodplain from beyond the original nonconforming structure’s 3-D building envelope must determine the floodway in accordance with § 15.3.045. If the encroachment is in the floodway, it must meet the standards in § 15.3.023(D). Subsequent improvements to repair or reconstructed nonconforming structures must not increase the degree of their nonconformity.
(15) In zone AO, repair or reconstruction of nonconforming structures and substantial improvements of residential structures must have the lowest floor (including basement) elevated above the highest adjacent grade at least as high as the depth number specified in feet on the FIRM (at least 2 feet if no depth number is specified). Subsequent improvements to repair or reconstructed nonconforming structures must not increase the degree of their nonconformity; or
(16) In zone AO, repair or reconstruction of nonconforming structures and substantial improvements of nonresidential structures must have the lowest floor (including basement) elevated above the highest adjacent grade at least as high as the depth number specified in feet on the FIRM (at least 2 feet if no depth number is specified), or (together with attendant utility and sanitary facilities) be structurally dry-floodproofed to that level according to the standard specified in division (D)(7) above. Subsequent improvements to repair or reconstructed nonconforming structures must not increase the degree of their nonconformity.
(Ord. 904, passed 5-2-06; Am. Ord. 1095, passed 1-16-24)