NR 115.05(1)(e)2m.c. c. An additional area of highly developed shoreline under subd. 2m. b., shall include at least 500 feet of shoreline and as of February 1, 2010, have either a majority of its lots developed with more than 30% impervious surface area as calculated under subd. 1m. or be located on a lake and served by a sewerage system as defined in s. NR 110.03 (30). To obtain approval from the department for an additional area, the county shall provide data to the department that establishes that the additional area meets the criteria under this subd. 2m. c.

NR 115.05(1)(e)3. 3. ‘Maximum impervious surface.’ A county may allow a property owner to exceed the impervious surface standard under subds. 2. and 2m. provided that all of the following requirements are met:

NR 115.05(1)(e)3.a. a. For lots or parcels described under subd. 1. that exceed the impervious surface standard under subd. 2. and are not located within a highly developed shoreline as defined in subd. 2m., a county may allow more than 15% impervious surface but not more than 30% impervious surface as calculated under subd. 1m on the lot or parcel.

NR 115.05(1)(e)3.b. b. For lots or parcels described under subd. 1. and located within an area defined by county ordinance as a highly developed shoreline under subd. 2m., a county may allow more than 30% impervious surface but not more than 40% impervious surface as calculated under subd. 1m on the lot or parcel for properties that have a residential land use, or more than 40% impervious surface but not more than 60% impervious surface as calculated under subd. 1m. for properties that have a commercial, industrial or business land use.

NR 115.05(1)(e)3.c. c. For lots or parcels described under subd. 1 that exceed the impervious surface standard under subds. 2. and 2m., but do not exceed the maximum impervious surface standard under subd. 3. a. or b., the county shall issue a permit that requires a mitigation plan approved by the county and implemented by the property owner by the date specified in the permit. The mitigation plan shall include enforceable obligations of the property owner to establish or maintain measures that the county determines adequate to offset the impacts of the impervious surface on water quality, near-shore aquatic habitat, upland wildlife habitat and natural scenic beauty. The mitigation measures shall be proportional to the amount and impacts of the impervious surface being permitted. The obligations of the property owner under the mitigation plan shall be evidenced by an instrument recorded in the office of the county register of deeds.

NR 115.05(1)(e)3m. 3m. ‘Treated impervious surfaces.’ A county may exclude from the calculation under subdivision 1m., any impervious surface where the property owner can show that runoff from the impervious surface is treated by devices such as stormwater ponds, constructed wetlands, infiltration basins, rain gardens, bioswales or other engineered systems, or that the runoff discharges to internally drained pervious area that retains the runoff on the parcel to allow infiltration into the soil.

NR 115.05 Note Note: A property owner may seek a variance to a dimensional standard of the county ordinance, for areas that exceed the maximum impervious surface standard in subd. 3. and do not meet the provisions in subd. 3m. A county board of adjustment must review the request pursuant to s. 59.694 (7) (c), Stats., and applicable case law.

NR 115.05 Note Note: Nothing in this paragraph shall be construed to supersede the setback provisions in par. (b). New structures must meet all setback provisions in the county shoreland ordinance unless the property owner obtains a variance from the County Board of Adjustment.

NR 115.05(1)(e)4. 4. ‘Existing impervious surfaces.’ For existing impervious surfaces that were lawfully placed when constructed but that do not comply with the standards in subds. 2. and 3., the property owner may do any of the following as long as the property owner does not increase the percentage of impervious surface that existed on the effective date of the county shoreland ordinance:

NR 115.05(1)(e)4.a. a. Maintain and repair all impervious surfaces.

NR 115.05(1)(e)4.b. b. Replace existing impervious surfaces with similar surfaces within the existing building envelope.

NR 115.05(1)(e)4.c. c. Relocate or modify existing impervious surfaces with similar or different impervious surfaces, provided that the relocation or modification meets the applicable setback requirements in par. (b).

NR 115.05 Note Note: For example this provision would allow an existing at-grade patio to be removed and replaced with a new building, if the new building meets the shoreland setback requirements.

NR 115.05 Note Note: Nothing in this paragraph shall be construed to supersede other provisions in county shoreland ordinances.

NR 115.05(1)(f) (f) Height. To protect and preserve wildlife habitat and natural scenic beauty, on or after February 1, 2010, a county may not permit any construction that results in a structure taller than 35 feet within 75 feet of the ordinary high-water mark of any navigable waters.

NR 115.05(1)(g) (g) Nonconforming structures and uses.

NR 115.05(1)(g)1. 1. ‘General rule for nonconforming uses.’ Pursuant to ss. 59.69 (10) and 59.692 (2) (a), Stats., an ordinance enacted under those provisions may not prohibit the continuation of the lawful use of a building, structure or property, that exists when an ordinance or ordinance amendment takes effect, which is not in conformity with the provisions of the ordinance or amendment.

NR 115.05(1)(g)2. 2. ‘Nonconforming use of temporary structure.’ The continuance of the nonconforming use of a temporary structure may be prohibited.

NR 115.05(1)(g)3. 3. ‘Discontinued nonconforming use.’ If a nonconforming use is discontinued for a period of 12 months, any future use of the building, structure or property shall conform to the ordinance.

NR 115.05(1)(g)4. 4. ‘Maintenance of nonconforming principal structure.’ An existing principal structure that was lawfully placed when constructed but that does not comply with the required building setback under par. (b) 1. may be maintained and repaired within its existing building envelope. Maintenance and repair also includes such activities as interior remodeling, exterior remodeling, and the replacement or enhancement of plumbing or electrical systems, insulation, windows, doors, siding, or roof within the existing building envelope.

NR 115.05(1)(g)5. 5. ‘Expansion of nonconforming principal structure within the setback.’ An existing principal structure that was lawfully placed when constructed but that does not comply with the required building setback under par. (b) 1. may be expanded laterally or vertically, provided that all of the following requirements are met:

NR 115.05(1)(g)5.a. a. The use of the structure has not been discontinued for a period of 12 months or more if a nonconforming use.

NR 115.05(1)(g)5.b. b. The existing principal structure is at least 35 feet from the ordinary high-water mark.

NR 115.05(1)(g)5.c. c. Vertical expansion is limited to the height allowed in s. NR 115.05 (1) (f) and lateral expansions are limited to a maximum of 200 square feet over the life of the structure. No portion of the expansion may be any closer to the ordinary high-water mark than the closest point of the existing principal structure.

NR 115.05(1)(g)5.d. d. The county shall issue a permit that requires a mitigation plan that shall be approved by the county and implemented by the property owner by the date specified in the permit. The mitigation plan shall include enforceable obligations of the property owner to establish or maintain measures that the county determines adequate to offset the impacts of the permitted expansion on water quality, near-shore aquatic habitat, upland wildlife habitat and natural scenic beauty. The mitigation measures shall be proportional to the amount and impacts of the expansion being permitted. The obligations of the property owner under the mitigation plan shall be evidenced by an instrument recorded in the office of the county register of deeds.

NR 115.05(1)(g)5.e. e. All other provisions of the shoreland ordinance shall be met.

NR 115.05 Note Note: Other provisions include requirements such as impervious surface limitations.

NR 115.05(1)(g)5m. 5m. ‘Expansion of nonconforming principal structure beyond setback.’ An existing principal structure that was lawfully placed when constructed but that does not comply with the required building setback under par. (b) 1., may be expanded horizontally, landward or vertically provided that the expanded area meets the building setback requirements in par. (b) 1., and that all other provisions of the shoreland ordinance are met. A mitigation plan is not required solely for expansion under this paragraph, but may be required under par. (e) 3.

NR 115.05(1)(g)6. 6. ‘Replacement or relocation of nonconforming principal structure.’ An existing principal structure that was lawfully placed when constructed but that does not comply with the required building setback under par. (b) 1. may be replaced or relocated on the property provided all of the following requirements are met: