NR 151.242(3) (3) Delayed implementation. For municipalities that are regulated under subch. I of ch. NR 216 and for transportation facilities under the jurisdiction of the department of transportation for maintenance purposes that are located within municipalities regulated under subch. I of ch. NR 216, the highway reconstruction total suspended solids performance standard first applies January 1, 2017.

NR 151.242(4) (4) Maximum extent practicable. If the design cannot meet a total suspended solids reduction performance standard of sub. (1), Table 1., the storm water management plan shall include a written, site-specific explanation of why the total suspended solids reduction performance standard cannot be met and why the total suspended solids load will be reduced only to the maximum extent practicable. The department may not require any person to exceed the applicable total suspended solids reduction performance standard to meet the requirements of maximum extent practicable.

NR 151.242 Note Note: Pollutant loading models such as DETPOND, SLAMM, P8, or equivalent methodology may be used to evaluate the efficiency of the design in reducing total suspended solids. Information on how to access these models is available from the department’s storm water management program at dnr.wi.gov. Use the most recent version of the model and the rainfall files and other parameter files identified for Wisconsin users unless directed otherwise by the regulatory authority.

NR 151.242(5) (5) Off-site drainage. When designing BMPs, runoff draining to the BMP from off-site shall be taken into account in determining the treatment efficiency of the practice. Any impact on the efficiency shall be compensated for by increasing the size of the BMP accordingly.

NR 151.242 History History: CR 09-112: cr. Register December 2010 No. 660, eff. 1-1-11.

NR 151.243 NR 151.243 Peak discharge performance standard.

NR 151.243(1) (1) Requirement. By design, BMPs shall be employed to maintain or reduce the 1-year, 24-hour and the 2-year, 24-hour post-construction peak runoff discharge rates to the 1-year, 24-hour and the 2-year, 24-hour pre-development peak runoff discharge rates respectively, or to the maximum extent practicable. The runoff curve numbers in Table 2. shall be used to represent the actual pre-development condition.

- See PDF for table

NR 151.243 Note Note: Where the pre-development condition is a combination of woodland, grassland, or cropland, the runoff curve number should be pro-rated by area.

NR 151.243(2) (2) Exemptions. This section does not apply to the following:

NR 151.243(2)(a) (a) A transportation facility post-construction site where the discharge is directly into a lake over 5,000 acres or a stream or river segment draining more than 500 square miles.

NR 151.243(2)(b) (b) Except as provided under s. NR 151.241 (4), a transportation facility that is part of a redevelopment project.

NR 151.243(2)(c) (c) Except as provided under s. NR 151.241 (4), a highway reconstruction site.

NR 151.243 Note Note: The intent of s. NR 151.243 is to minimize streambank and shoreline erosion under bank-full conditions.

NR 151.243 History History: CR 09-112: cr. Register December 2010 No. 660, eff. 1-1-11.

NR 151.244 NR 151.244 Infiltration performance standard.

NR 151.244(1) (1) Requirement. Except as provided in sub. (2), the requirements are the same as those given in s. NR 151.124.

NR 151.244(2) (2) Exemptions. Except as provided under s. NR 151.241 (4), transportation facility highway reconstruction and new highways are not required to meet the performance standards of this section.

NR 151.244 History History: CR 09-112: cr. Register December 2010 No. 660, eff. 1-1-11; renumbering of (1), (2) made under s. 13.92 (4) (b) 1., Stats., Register December 2010 No. 660.

NR 151.245 NR 151.245 Protective areas performance standard.

NR 151.245(1) (1) Definition. In this section, “protective area” means an area of land that commences at the top of the channel of lakes, streams, and rivers, or at the delineated boundary of wetlands, and that is the greatest of the following widths, as measured horizontally from the top of the channel or delineated wetland boundary to the closest impervious surface. However, in this section, “protective area” does not include any area of land adjacent to any stream enclosed within a pipe or culvert, so that runoff cannot enter the enclosure at this location.

NR 151.245(1)(a) (a) For outstanding resource waters and exceptional resource waters, 75 feet.

NR 151.245(1)(b) (b) For perennial and intermittent streams identified on a U.S. geological survey 7.5-minute series topographic map, or a county soil survey map, whichever is more current, 50 feet.

NR 151.245(1)(c) (c) For lakes, 50 feet.

NR 151.245(1)(d) (d) For wetlands not subject to par. (e) or (f), 50 feet.

NR 151.245(1)(e) (e) For highly susceptible wetlands, 75 feet. Highly susceptible wetlands include the following types: calcareous fens, sedge meadows, open and coniferous bogs, low prairies, coniferous swamps, lowland hardwood swamps, and ephemeral ponds.

NR 151.245 Note Note: Information on wetland types, including ephemeral ponds, is available from the department at [phone].

NR 151.245(1)(f) (f) For less susceptible wetlands, 10 percent of the average wetland width, but no less than 10 feet nor more than 30 feet. Less susceptible wetlands include: degraded wetlands dominated by invasive species such as reed canary grass; cultivated hydric soils; and any gravel pits, or dredged material or fill material disposal sites that take on the attributes of a wetland.

NR 151.245(1)(g) (g) In pars. (d) to (f), determinations of the extent of the protective area adjacent to wetlands shall be made on the basis of the sensitivity and runoff susceptibility of the wetland in accordance with the standards and criteria in s. NR 103.03.