NR 151.241(4)(4) Maintenance of effort. For non-highway transportation facility redevelopment sites and highway reconstruction where the redevelopment or reconstruction will be replacing older development or highway that was subject to post-construction performance standards of this chapter in effect on or after October 1, 2004, the responsible party shall meet the total suspended solids reduction, peak flow control, infiltration, and protective areas standards applicable to the older development or highway, or meet the redevelopment or highway reconstruction standards of ss. NR 151.242 to 151.249, whichever are more stringent. NR 151.241 HistoryHistory: CR 09-112: cr. Register December 2010 No. 660, eff. 1-1-11. NR 151.242NR 151.242 Total suspended solids performance standard. NR 151.242(1)(1) Requirement. Except as provided in sub. (3), BMPs shall be designed, installed, and maintained to control total suspended solids carried in runoff from the transportation facility post-construction site. BMPs shall be designed in accordance with Table 1., or to the maximum extent practicable as provided in sub. (4). The design shall be based on an average annual rainfall, as compared to no runoff management controls. NR 151.242(2)(2) Non-highway transportation redevelopment and highway reconstruction. Except as provided in s. NR 151.241 (4), the non-highway transportation facility redevelopment and highway reconstruction total suspended solids reduction standard of Table 1. applies to non-highway transportation facility redevelopment and highway reconstruction. 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 NoteNote: 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 HistoryHistory: CR 09-112: cr. Register December 2010 No. 660, eff. 1-1-11. NR 151.243NR 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. NR 151.243 NoteNote: 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 NoteNote: The intent of s. NR 151.243 is to minimize streambank and shoreline erosion under bank-full conditions. NR 151.243 HistoryHistory: CR 09-112: cr. Register December 2010 No. 660, eff. 1-1-11. NR 151.244NR 151.244 Infiltration performance standard. 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 HistoryHistory: 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 151.245NR 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.