A. 
Nonconforming uses.
(1) 
These requirements shall take precedence over general zoning requirements for nonconforming uses in the Riverway District.
(2) 
A nonconforming use may not be expanded or enlarged.
(3) 
An increase in the volume, intensity or frequency of use is allowed if neither the land area nor the structure used for the nonconforming use is expanded or enlarged and if the owner provides a site plan and photographs of the site to the Zoning Administrator to be kept in a property file at the Land Management Department.
(4) 
A change from one nonconforming use to another nonconforming use is not allowed.
(5) 
If a nonconforming use is discontinued for a period of 12 consecutive months, any future use of buildings and premises shall conform to all of the requirements of the Pierce County Zoning Ordinance.[1]
[1]
Editor's Note: See Ch. 240, Zoning.
B. 
Nonconforming principal structures.
(1) 
These requirements shall take precedence over general zoning requirements for nonconforming structures in the Riverway District, except where those requirements are more restrictive, in which case the most restrictive requirements shall apply.
(2) 
Ordinary maintenance and repair of a nonconforming principal structure is allowed.
(3) 
Structural alteration, reconstruction and expansion of a nonconforming principal structure and replacement, improvement or structural alteration of the foundation is allowed by a land use permit if all of the applicable requirements in Subsection B(4) and (5) below are met.
(4) 
Reconstruction of nonconforming principal structures. Nonconforming principal structures located within the OHWM setback area, bluffline setback area or slope preservation zone may be structurally altered or reconstructed and foundations may be replaced, improved or structurally altered if all of the following requirements are met:
(a) 
The lot has an area of at least 7,000 square feet.
(b) 
The altered or reconstructed structure will be visually inconspicuous or will be rendered so through mitigation per Subsection E.
(c) 
The structure is altered or reconstructed in the same footprint as the preexisting structure.
(d) 
The reconstructed structure may not be any taller than the preexisting nonconforming structure, except that a flat roof may be replaced with a pitched roof and may not be taller than allowed per § 239-9D.
(e) 
The color of the structure complies with § 239-10A.
(f) 
The property owner submits a mitigation plan per Subsection E.
[1] 
If a permit is issued for the reconstruction, the mitigation plan shall be approved, or modified and approved, by the Zoning Administrator.
[2] 
The mitigation plan shall be incorporated into the permit, and the property owner shall be required to implement the mitigation plan as a permit condition.
(g) 
Private on-site wastewater treatment systems are brought into compliance with the requirements of Wisconsin Administrative Code Chapter Comm. 83 and the Pierce County Sanitary Ordinance.
(h) 
The foundation of the structure may not be replaced, improved or structurally altered unless all of the following standards are met:
[1] 
The foundation work is being done in conjunction with the reconstruction of the structure;
[2] 
The entire structure is entirely located more than 50 feet from the OHWM; and
[3] 
The entire structure is not located in a slope preservation zone.
(i) 
An erosion control plan and revegetation plan shall be submitted for approval, or modification and approval, to the Zoning Administrator prior to the issuance of a permit for structural alteration or reconstruction.
(j) 
No filling and grading activities are allowed during the alteration or reconstruction, except for the minimum necessary to accomplish the alteration or reconstruction in compliance with other provisions of this chapter, and as needed to upgrade a private on-site wastewater treatment system, to replace sewer or water laterals, or to install stormwater or erosion control measures.
(k) 
If the structure is located in a slope preservation zone, it may be reconstructed on the existing foundation only if WDNR stormwater technical standards applicable to steeper sloped areas are implemented to control erosion.
(5) 
Expansion of nonconforming principal structures.
(a) 
Nonconforming principal structures located in the OHWM setback area or bluffline setback area may be expanded and the preexisting foundation may be replaced, repaired or structurally altered in conjunction with the expansion if all of the applicable following requirements are met:
[1] 
Structures located wholly or partially within 50 feet of the OHWM may not be expanded.
[2] 
Structures located wholly or partially within a slope preservation zone may not be expanded.
[3] 
Structures entirely set back more than 50 feet from the OHWM but located wholly or partially less than 75 feet from the ordinary high-water mark may be expanded only if there is no compliant building location available on the lot.
[4] 
Structures entirely set back more than 75 feet from the ordinary high-water mark may be expanded regardless of whether a compliant building location exists elsewhere on the lot.
[5] 
The lot has an area of at least 7,000 square feet.
[6] 
The expanded structure will be visually inconspicuous or will be rendered so through mitigation.
[7] 
Any reconstructed portion of the nonconforming structure may only be reconstructed in the same footprint as the preexisting structure. Notwithstanding the definition of "reconstruction" in Wisconsin Administrative Code Section NR 118.03(36), the preexisting foundation of a structure that is more than 50 feet from the ordinary high-water mark and is not within a slope preservation zone may be replaced, repaired or structurally altered in conjunction with the expansion of the structure.
[8] 
For structures located wholly or partially within the OHWM setback area, the total footprint of the structure may not exceed 1,500 square feet.
[9] 
For structures located wholly or partially within the bluffline setback, but not within the OHWM setback area, the total footprint of the structure may not exceed 2,000 square feet, and the structure shall comply with all of the following requirements:
[a] 
The structure is set back at least 40 feet from the bluffline.
[b] 
The structure does not protrude above the bluffline as viewed from at or near the midline of the river or from 250 feet riverward from the OHWM, whichever is less.
[c] 
The structure is not located within the slope preservation zone.
[d] 
The structure uses earthtone building materials that are of a nonreflective nature, except that windows may be made of ordinary glass or nonreflective glass but may not be made of glass designed to reflect more light than ordinary window glass.
[e] 
The structure is visually inconspicuous.
[10] 
Expansion is on the side of the structure farthest from the river, or if landward expansion is not possible, the expansion is parallel to the OHWM or bluffline.
[11] 
The height of the altered or reconstructed structure complies with § 239-9D.
[12] 
The color of the structure complies with § 239-10A.
[13] 
The property owner submits a mitigation plan per Subsection E.
[a] 
If a permit is issued for the expansion, the mitigation plan shall be approved, or modified and approved, by the Zoning Administrator.
[b] 
The mitigation plan shall be incorporated into the permit, and the property owner shall be required to implement the mitigation plan as a permit condition.
[14] 
Private on-site wastewater treatment systems are brought into compliance with the requirements of Wisconsin Administrative Code Chapter Comm 83 and the Pierce County Sanitary Ordinance.
[15] 
Filling or grading is not allowed as part of the reconstruction or expansion except as necessary to reconstruct or build the expansion in compliance with other provisions of this chapter, upgrade a private on-site wastewater treatment system, replace sewer or water laterals, or install stormwater or erosion control measures.
[16] 
An erosion control plan and revegetation plan shall be submitted for approval, or modification and approval, to the Zoning Administrator prior to the issuance of a permit for the expansion.
(b) 
Expansion of nonconforming principal structures summarized.
Distance from OHWM
Less than 50 feet
50 to 75 feet
Greater than 75 feet
No expansion
Expansion only if no other compliant building location on lot
Expansion up to a total footprint of 1,500 square feet
C. 
Nonconforming accessory structures.
(1) 
Ordinary maintenance and repair of nonconforming accessory structures is allowed.
(2) 
Nonconforming accessory structures may not be structurally altered, reconstructed or expanded, except that garages and storage sheds may be structurally altered, reconstructed or expanded if all of the following requirements are met where applicable:
(a) 
The entire garage or storage shed is not located in a slope preservation zone.
(b) 
The entire garage or storage shed is set back more than 75 feet from the OHWM.
(c) 
The garage or storage shed is not used for human habitation.
(d) 
The total footprint of all nonconforming accessory structures, other than existing driveways, within 75 feet of the OHWM, within a slope preservation zone or within the bluffline setback area may not exceed 500 square feet.
(e) 
All parts of the garage or storage shed shall be finished in earthtone colors and materials that are nonreflective, except that windows may be made of ordinary window glass or nonreflective glass, but may not be made of glass designed to reflect more light than ordinary window glass.
(f) 
Mitigation measures are implemented and maintained per Subsection E.
(g) 
The structure is visually inconspicuous or will be rendered so through a mitigation plan per Subsection E.
D. 
Substandard lots. Lots of record in the Register of Deeds office on January 1, 1976, or on the date of the enactment of an amendment to this chapter that makes the lot substandard, which do not meet the requirements of this chapter may be allowed as building sites, provided that the following criteria are met:
(1) 
The lot is in separate ownership from abutting lands; or
(2) 
The lot by itself or in combination with an adjacent lot or lots under common ownership in an existing subdivision has at least one acre of net project area. Adjacent substandard lots in common ownership may only be sold or developed as separate lots if each of the lots has at least one acre of net project area.
(3) 
All structures that are proposed to be constructed or placed on the lot and the proposed use of the lot comply with the requirements of this chapter and any underlying zoning or sanitary code requirements.
E. 
Mitigation requirements.
(1) 
Expansion or reconstruction of nonconforming principal structures, and the expansion, reconstruction or structural alteration of nonconforming accessory structures, shall trigger mitigation requirements to offset the impacts of the proposed project.
(2) 
Mitigation measures shall be roughly proportional to the magnitude of the impacts of the proposed project on scenic resources, water quality, erosion potential and the protection of the shoreland area.
(3) 
Mitigation shall include, but is not limited to, the following:
(a) 
Planting trees and shrubs capable of screening the entire structure if existing vegetation is not sufficient to render the structure visually inconspicuous per §§ 239-7B and 239-10G. Additionally:
[1] 
All trees and shrubs shall be native to the area.
[2] 
All trees shall be at least two inches diameter at breast height (DBH) and planted no more than 12 feet apart and parallel to the river and the structures they screen. To allow for future growth, these trees may be planted at different locations and staggered between the structures and the river.
(b) 
The vegetation in the area within 50 feet of the OHWM shall be preserved or restored through planting of native vegetation per § 239-10G.
[1] 
Vegetation shall be established or maintained at densities that are adequate to protect water quality, habitat and the natural scenic beauty of the shoreland area.
[2] 
If a nonconforming structure is located in this area, the vegetation shall be planted surrounding the structure, although the owner may create a screened view of the river from the structure and may leave a fifteen-foot-wide mowed area around the structure to protect it from wildfire.
(c) 
Best management practices shall be followed to encourage stormwater infiltration and to limit erosion and runoff.
(d) 
An affidavit describing the approved mitigation plan shall be executed and recorded with the County Register of Deeds by the property owner within 14 days after approval of the mitigation plan. The affidavit shall alert all subsequent purchasers of the land of the requirements of the mitigation plan.