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
73 55 22.0
85 54 25.3
81 59 26
87 63 31
95 67 35
103 71 40
NR 320.07(3)(3) Culvert length determination. The proper culvert length is determined by the following calculation: NR 320.07 HistoryHistory: CR 04-084: cr. Register April 2005 No. 592, eff. 5-1-05. NR 320.08(1)(1) Noncompliance with the provisions of ss. 30.12, 30.123, 30.20 and 30.206, Stats., this chapter, or any conditions of an exemption, general permit or individual permit issued by the department, constitutes a violation and may result in a forfeiture. The department may seek abatement under s. 30.294, Stats., for any activity in violation of ss. 30.12, 30.123, 30.20 and 30.206, Stats. NR 320.08(2)(2) If the activity may be authorized by a general permit under s. 30.206, Stats., failure of an applicant to follow the procedural requirements may not, by itself, result in abatement of the activity. NR 320.08(3)(3) When an after-the-fact permit application has been filed with the department, the department shall follow the procedures in ch. NR 300 for violations. NR 320.08(4)(4) Any violation of these rules shall be treated as a violation of the statutes they interpret or are promulgated under. NR 320.08(5)(5) No person may place a bridge or culvert in or over a navigable waterway if the activity is not eligible for an exemption, authorized by a general permit or individual permit issued under this chapter, or otherwise authorized under this chapter. NR 320.08 HistoryHistory: CR 04-084: cr. Register April 2005 No. 592, eff. 5-1-05; CR 22-013: am. (3) Register June 2023 No. 810, eff. 7-1-23.
