NR 320.06 NoteNote: Local zoning ordinances may place restrictions on activities located in mapped floodplains or in shoreland zones. The riparian is responsible for ensuring that their project is in compliance with any local zoning requirements as well as the provisions of this chapter.
NR 320.06(2)(c)7.7. Approach fill shall be a maximum of one foot deep at the bank and 0 feet at 15 feet landward of the bank. If depth of greater than one foot of approach fill is required or the approach must be located in a wetland, it shall be of an open ramp style that does not impede flow. Geotextile fabric shall be placed under approach fill to facilitate removal and reduce soil compaction. NR 320.06(2)(c)8.8. Accumulated brush, debris and other obstructions that are trapped in or underneath the structure shall be regularly removed to prevent upstream flooding and maintain structural integrity. NR 320.06(2)(c)9.9. The permittee shall submit a series of photographs to the department within one week of placing the structure on this site and within one week of stabilizing disturbed areas on the site after the removal of the structure. The photographs shall be taken from different vantage points and depict all work authorized by the permit. NR 320.06(2)(c)10.10. To stop the spread of invasive species and viruses from one navigable waterway to another navigable waterway, all equipment or portions of equipment used for constructing, operating, or maintaining the project, including tracked vehicles, barges, boats, silt or turbidity curtains, hoses, sheet piles, and pumps, shall be decontaminated for invasive species and viruses before and after use or prior to use within another navigable waterway. Decontamination activities shall be performed by taking actions specified in subd. 10. a. to c. or h. Decontamination shall include either subd. 10. d., e., f., g., or h. for any equipment, or portions of equipment, that is used in non-frozen navigable waters when the air temperature is above 19 degrees Fahrenheit at the time the decontamination procedures take place. NR 320.06(2)(c)10.a.a. Inspect all equipment used for constructing, operating, or maintaining the project and remove all plants and animals, and other mud, debris, etc. NR 320.06 NoteNote: This does not apply to water in closed engine cooling systems or water tanks, or containers of potable drinking water or other beverages meant for human consumption. If a tanker truck discharges water collected from navigable waters in upland areas, the tank does not require disinfection.
NR 320.06(2)(c)10.c.c. Dispose of plants and animals in the trash. An operator may not transfer plants or animals or water from one navigable waterway to another. NR 320.06(2)(c)10.d.d. Wash equipment at a temperature of not less than 212 degrees Fahrenheit water (steam clean). NR 320.06(2)(c)10.e.e. Wash equipment with soap and water or high pressure water of not less than 2000 pounds per square inch. NR 320.06 NoteNote: Additional drying techniques including drying through natural or mechanical means or changes in drying duration may be submitted to the department for review and approval.
NR 320.06(2)(c)10.g.g. Disinfect equipment with 200 parts per million (0.5 ounces per gallon) chlorine for not less than 10 minute contact time. Every effort should be made to keep the disinfection solution and rinse water out of surface waters. NR 320.06 NoteNote: Chlorine refers to either household bleach solution (5.25% chlorine) or granular chlorine (70% calcium hypochlorite)
NR 320.06(2)(c)10.h.h. Follow the most recent department approved disinfection protocols or department approved best management practices for infested waters. The department shall maintain on its website and make available at its offices a list of the most recent disinfection protocols or department approved best management practices for invasive species and viruses. NR 320.06 NoteNote: See the department’s website at dnr.wi.gov under the topic “Waterway and Wetlands”. Recommendations for additional disinfection or decontamination protocols or department approved best management practices may be submitted to the department for review and approval to be added to this list.
NR 320.06(2)(d)(d) Standards for placement of clear span bridges over navigable streams. NR 320.06(2)(d)1.1. The clear span bridge may only span a navigable stream that is less than 35 feet wide, measured from ordinary high water mark to ordinary high water mark. NR 320.06(2)(d)2.2. The clear span bridge may not be located on a wild river designated under ch. NR 302, or where similar federal, state or local regulations prohibit the construction. NR 320.06(2)(d)3.3. At least one end of the bridge structure shall be firmly anchored in a manner that the bridge will not be transported downstream during flood conditions. NR 320.06(2)(d)4.4. The bridge shall completely span the navigable stream from top of channel to top of channel with no support pilings in the stream. NR 320.06(2)(e)(e) Standards for culvert placement on navigable streams without a professionally engineered culvert design. NR 320.06(2)(e)3.3. Culvert placement and installation shall mimic the natural streambed and gradient above and below the culvert channel. Perched culverts are not in compliance with this condition. NR 320.06(2)(e)4.4. If flow conditions require the use of a multiple culvert arrangement, culverts shall be placed at varying elevations, one in the bed and the other at 4″ to 8″ higher, to facilitate base and low flows as well as larger rain or snowmelt events. NR 320.06(2)(e)5.5. Both ends of the culvert shall be installed so a minimum of 4″ and a maximum of 8″ for a round culvert and 6″ for a pipe arch culvert lies below the bed of the waterway. NR 320.06(2)(e)6.6. Culvert inlets may not be capped with screens, bars or any other means, with the exception of beaver control procedures, which prevent movement of fish or wildlife or collect debris. NR 320.06(2)(e)7.7. Culverts shall be designed to prevent washout. Culverts shall be long enough so road fill does not extend beyond the ends of the culvert. The culvert shall extend at least one foot beyond the fill. The channel shall be protected with variable-sized riprap extending horizontally at least 2 times the culvert diameter or height of arch culvert from the end of the culvert. Riprap placement shall include an adequate filter layer or filter fabric as illustrated in sub. (1) (c) 9. NR 320.06(2)(e)8.8. Clean fill material shall be firmly compacted around the culvert as illustrated in sub. (1) (c) 10. Multiple culvert crossings shall have a minimum of 2 feet clearance between adjacent culverts to allow adequate compaction of fill material. The culvert shall be designed or protected to prevent crushing. NR 320.06(2)(e)9.9. Dredging and deposition of sand, gravel or stone on the streambed may be associated with the placement of a culvert provided that the dredging is limited to the volume necessary to bury the culvert as required in this section and the deposit is limited to the area immediately underneath or within 2 feet of the culvert. NR 320.06(2)(e)10.10. Issuance of a general permit under this paragraph constitutes a waiver of the vertical clearance standards under s. NR 320.04. NR 320.06(2)(f)(f) Standards for culvert placement on navigable streams with a professionally engineered culvert design. NR 320.06(2)(f)2.2. The activity shall meet all the standards in par. (e) with the following exception: The required culvert area may not exceed 40 square feet as calculated in s. NR 320.07 (1). NR 320.06(2)(g)(g) Standards for placement of temporary in-stream crossings on navigable streams. NR 320.06(2)(g)1.1. The temporary in-stream crossing shall be used to provide temporary access to an area for forest management activities that are taken on forest land to establish, maintain or enhance a forest including planting trees, thinning and trimming trees, and harvesting timber and other forest products. NR 320.06(2)(g)2.2. The temporary in-stream crossing may only span a navigable stream that is less than 10 feet wide, measured from ordinary high water mark to ordinary high water mark. NR 320.06(2)(g)3.3. The temporary in-stream crossing may not be located on a wild river designated under ch. NR 302, or where similar federal, state or local regulations prohibit the construction. NR 320.06(2)(g)4.4. The temporary in-stream crossing shall consist of poles, small logs, or pipes placed side by side in the stream channel parallel to the stream flow. Geotextile fabric shall be placed under the poles, small logs, or pipes and under any associated approach fill. NR 320.06(2)(g)5.5. For trout streams identified under s. NR 1.02 (7) and navigable tributaries to those trout streams, the temporary in-stream crossing shall include a culvert with a minimum diameter of 12 inches. The culvert shall be placed on the streambed and may not obstruct fish passage. Poles, small logs, or pipes may be placed side by side parallel to stream flow over the culvert. Geotextile fabric shall be placed under the culvert, poles, small logs, or pipes and under any associated approach fill. NR 320.06(2)(g)6.6. The temporary in-stream crossing shall be placed and removed during frozen or low flow conditions. NR 320.06 NoteNote: Frozen conditions would exist when the stream is covered with ice thick enough to support vehicles and low flow conditions would exist when there is little or no water in the streambed.
NR 320.06(2)(g)7.7. The poles, small logs, or pipes shall be cabled, chained or banded together prior to installation to facilitate removal. NR 320.06(2)(g)8.8. The temporary in-stream crossing shall be removed after the project requiring temporary access is completed or 160 days after installation, whichever occurs first. NR 320.06 NoteNote: Removal of a temporary in-stream crossing must comply with the time periods specified in par. (b) 3.
NR 320.06(2)(g)9.9. The temporary in-stream crossing shall be installed and removed a single time, except for maintenance of the structure as authorized in par. (c) 8. NR 320.06(2)(g)10.10. Issuance of a general permit under this paragraph constitutes a waiver of the vertical clearance standards under s. NR 320.04. NR 320.06(2)(h)1.1. Activities that do not meet the standards in par. (c) and either par. (d), (e), (f), or (g), or a general permit issued by the department shall require an individual permit. NR 320.06(3)(a)2.2. If the department determines that a proposal submitted under this section has the potential to impact an endangered or threatened species in accordance with s. 29.604, Stats., the application shall be deemed incomplete. The department may not consider the application complete or issue an individual permit until the applicant submits documentation to demonstrate one of the following: NR 320.06(3)(a)2.a.a. The project avoids impacts to the endangered or threatened species in accordance with s. 29.604, Stats. NR 320.06(3)(a)3.3. If the applicant modifies the project plans to meet the requirements of subd. 2., the modified plans shall be submitted before the department may consider the application complete or issue an individual permit. NR 320.06(3)(b)(b) Applicable activities. Any bridge or culvert which is not exempt under sub. (1) and is not authorized by a general permit under sub. (2) requires authorization by an individual permit under s. 30.123 (8), Stats. Individual permits will be required for streams with required culvert areas in excess of 40 square feet. NR 320.06(3)(c)(c) Standards. Construction, placement or maintenance of a bridge or culvert that meets the standards in s. 30.123 (8) (c), Stats., may be authorized under an individual permit. NR 320.06 HistoryHistory: CR 04-084: cr. Register April 2005 No. 592, eff. 5-1-05; CR 06-038: am. (2) (b) and (c), r. and recr. (2) (d) and (e), renum. (2) (g) to be (2) (h) and am. (2) (h) 1., cr. (2) (g) Register January 2007 No. 613, eff. 2-1-07; CR 07-094: cr. (1) (c) 15., (d) 7. and (2) (c) 10. Register November 2008 No. 635, eff. 12-1-08; correction in (2) (b) made under s. 13.92 (4) (b) 7., Stats., Register May 2013 No. 689; CR 22-013: am. (1) (a), (2) (a) 1., (3) (a) 1. Register June 2023 No. 810, eff. 7-1-23. NR 320.07NR 320.07 Culvert area calculation, culvert sizing, and culvert length determination. Applicants shall use the following calculation and assessment methods: NR 320.07(1)(1) Calculation of required culvert area. To determine the required culvert area, 3 measurements shall be made: channel width of the stream in feet at the ordinary high water mark (W1), channel width of the stream in feet at the stream bottom (W2), and the height in feet of the high water above the stream bottom (H) (see diagram). These 3 measurements shall be made at each of 3 locations or transects along the stream: the location of the proposed crossing, 100 feet upstream from the crossing, and 100 feet downstream from the crossing. The individual measurements of W1, W2 and H shall be averaged to derive the final W1, W2 and H values. The required culvert area is then calculated with the following equation: Required Culvert area (square feet) = H x (W1 + W2)
NR 320.07(2)(2) Culvert sizing. Once the required culvert area has been determined, the applicant can identify the proper culvert size by reviewing the following tables. The minimum size culvert needed to pass flows must have an area that is as much or more than the required culvert area. For example, the recommended culvert size for a culvert area calculation of 8.50 square feet would be 42″. Table 1. Round culvert diameters and corresponding culvert area.
Culvert diameter (in.) Culvert area (sq. ft.)
18 1.80
24 3.10
30 4.90
36 7.10
42 9.60
48 12.60
54 15.90
60 19.60
66 23.80
NR 320.07 NoteNote: To find the area of any round culvert, use the following equation:
NR 320.07 NoteCulvert diameter (in.) divided by 2 = _____ divided by 12 = _____ (radius in ft.)
NR 320.07 NoteRadius x Radius x 3.14 = _________ (area of culvert in sq. ft.)
Table 2. Pipe arch dimensions and corresponding culvert area.
Pipe width or span (in.) Pipe height or rise (in.) Culvert area (sq. ft.)
43 27 6.4
50 31 8.7
58 36 11.4
65 40 14.3
72 44 17.6
