Since we provided information to our members last summer about the State's proposal for new shoreland development rules known as NR115, there have been some adjustments. The adopted rules contain a new impervious surface standard that will not affect owners of existing homes and buildings, unless they propose major changes like remodeling or expansion.
The Wikipedia definition of an "impervious surface" is one where materials (as in new buildings or hard surfaces) seal the soil, eliminating rainwater infiltration which recharges natural groundwater. lt is estimated that impervious surface runoff is the primary source of pollution in 13% of rivers and 18% of lakes. Pollutants may include excess nutrients from fertilizers; pathogens from pet waste; gasoline and motor oil; and sediment from erosion at construction sites.
The new impervious surface rule applies to all shoreland within 300 ft. of a river and 1,000 ft. of the ordinary high water mark in a lake. Such surfaces cannot exceed 15% of the lot size without a permit showing a plan to control and manage water runoff.
ln the revised NR115 the 75-ft. setback still applies. Minimum lot size requirements have not changed. The old 50% rule limiting structural repairs and alterations has been repealed. The new rules do not impose spending limits on repairs to existing non-conforming residences located within 75 ft. of the water’s edge. If an existing house is at least 35 ft. back from the water, an owner can build a second story or otherwise add on vertically up to 35 ft. But if an owner wants to expand the physical footprint of a non-conforming structure, he or she will be required to offset the environmental impact by choosing among various mitigating options, such as limiting lawn mowing near water or putting in native vegetation.
Vilas County has two years to update its code and set specific mitigation requirements in its Shoreland Zoning Ordinance.