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NR 320.05   Bridge enforcement for municipal highway bridges.
NR 320.06   Bridges and culverts.
NR 320.07   Culvert area calculation, culvert sizing, and culvert length determination.
NR 320.08   Enforcement.
Ch. NR 320 Note Note: Chapter NR 320 was revised by emergency rule effective April 19, 2004; Chapter NR 320 was repealed and recreated by emergency rule effective August 24, 2004; Chapter NR 320 as it existed on April 30, 2005, was repealed and a new chapter NR 320 was created Register April 2005 No. 592, effective May 1, 2005.
NR 320.01 NR 320.01 Purpose. The purpose of this chapter is to establish reasonable procedures and limitations for exempt activities, general permits and individual permits for placement of bridges and culverts in or over navigable waterways as regulated under s. 30.123, Stats., in order to protect the public rights and interest in the navigable, public waters of the state as defined in s. 30.10, Stats.
NR 320.01 History History: CR 04-084: cr. Register April 2005 No. 592, eff. 5-1-05.
NR 320.02 NR 320.02 Applicability.
NR 320.02(1)(1) Bridges and culverts placement. This chapter applies to construction, placement and maintenance of bridges and culverts in or over navigable waterways as regulated under s. 30.123, Stats. Any person that intends to construct, place or maintain a bridge or culvert in or over any navigable waterway shall comply with all applicable provisions of this chapter and any permit issued under this chapter.
NR 320.02 Note Note: A permit that is granted under this chapter does not constitute review or authorization of floodplain effects. Where bridge or culvert activities occur in a mapped floodplain, permits will be required from the local municipality. The permittee shall assume all responsibility and liability for any direct or indirect damage caused or resulting from the presence of the bridge or culvert.
NR 320.02(2) (2)Municipal highway bridges.
NR 320.02(2)(a)(a) Municipalities are not required to obtain a permit or approval pursuant to s. 30.10, 30.12 or 31.23, Stats., prior to constructing a municipal highway bridge. However, municipal highway bridges cannot obstruct navigation. All municipal highway bridges shall be constructed or reconstructed in accordance with standards developed under s. 84.01, Stats.
NR 320.02 Note Note: Municipal highway bridges must continue to meet local floodplain zoning requirements.
NR 320.02(3) (3)State highway bridges. Intrastate and interstate bridges constructed pursuant to ss. 84.11 and 84.12, Stats., are subject to the control and supervision over the navigable waters of the state conferred by law upon the department. State highway bridges constructed pursuant to ss. 84.11 and 84.12, Stats., will be reviewed and approved by the department in accordance with interdepartmental liaison procedures established by the department and the department of transportation for the purpose of minimizing adverse environmental impacts under the procedures established in s. 30.2022, Stats.
NR 320.02 History History: CR 04-084: cr. Register April 2005 No. 592, eff. 5-1-05.
NR 320.03 NR 320.03 Definitions.
NR 320.03(1)(1) “ Area of special natural resource interest" has the meaning in s. 30.01 (1am), Stats., and as identified by the department in s. NR 1.05.
NR 320.03 Note Note: “Area of special natural resource interest" means any of the following:
NR 320.03 Note(a) A state natural area designated or dedicated under ss. 23.27 to 23.29, Stats.
NR 320.03 Note(b) A surface water identified as a trout stream by the department under s. NR 1.02(7).
NR 320.03 Note (bm) A surface water identified as an outstanding or exceptional resource water under s. 281.15, Stats.
NR 320.03 Note (c) An area that possesses significant scientific value, as identified by the department in s. NR 1.05.
NR 320.03 Note Information and lists can be obtained by contacting the department, or found on the department's website at, under the topic “Waterway and Wetland Permits".
NR 320.03(2) (2) “Backwater" means the increase in the water surface elevation that results from a bridge and any associated road fills under average water flow conditions.
NR 320.03(3) (3) “Bridge" means any private or public structure except municipal highway bridges constructed in or over a navigable waterway to provide a walkway or roadway for pedestrians, animals or vehicles, and includes pipe arches and culverts.
NR 320.03(4) (4) “Channel" means a natural or artificial water course with defined bed and banks to confine and conduct the normal flow of water.
NR 320.03(5) (5) “Clearance" means the vertical distance between the inside top of a culvert or the bottom of the lowest member of the bridge span and the ordinary high water mark of the waterway.
NR 320.03(6) (6) “Clear span bridge" means a continuous span of which no portion of the bridge piling or other supporting structure may be located within the channel except for abutment protection.
NR 320.03(7) (7) “Department" means the department of natural resources.
NR 320.03(8) (8) “Highway" or “public highway" has the meaning in s. 340.01 (22), Stats.
NR 320.03(9) (9) “Maintain" means to repair, replace, own or possess all or a portion of a structure.
NR 320.03(10) (10) “Municipal highway bridge" means any city, town, village or county owned structure built in or over a navigable waterway for public highway purposes.
NR 320.03(11) (11) “Navigable waterway" means any body of water with a defined bed and bank, which is navigable under the laws of the state. In Wisconsin, a navigable body of water is capable of floating the lightest boat or skiff used for recreation or any other purpose on a regularly recurring basis.
NR 320.03 Note Note: This incorporates the definition at s. 30.01(4m), Stats., and current case law, which requires a watercourse to have a bed and banks, Hoyt v. City of Hudson, 27 Wis. 656 (1871), and requires a navigable waterway to float on a regularly recurring basis the lightest boat or skiff, DeGayner & Co., Inc. v. DNR, 70 Wis. 2d 936 (1975); Village of Menomonee Falls v. DNR, 140 Wis.2d 579 (Ct. App. 1987).
NR 320.03(12) (12) “Ordinary high water mark" or “OHWM" means the point on the bank or shore up to which the presence and action of water is so continuous as to leave a distinct mark either by erosion, destruction of terrestrial vegetation or other easily recognized characteristic.
NR 320.03(13) (13) “Perched culvert" means a culvert where the inlet or outlet elevation is higher than the streambed elevation, thereby effectively reducing or eliminating fish migration and fish passage.
NR 320.03(14) (14) “Professionally engineered" means designed by a person registered as a professional engineer under s. 443.04, Stats., and ch. A-E 4.
NR 320.03(15) (15) “Replacement" means a degree of structural changes to a bridge or culvert by which some or all of the bridge or culvert is being removed or recreated.
NR 320.03(16) (16) “Riprap" means a layer or layers of rock, including filter material, placed on the bed and bank of a navigable waterway to prevent erosion, scour or sloughing of the existing bank.
NR 320.03(17) (17) “Temporary in-stream crossing" means any private or public structure placed within the channel of a navigable stream for 160 days or less to provide a walkway or roadway for pedestrians, animals or vehicles.
NR 320.03 History History: CR 04-084: cr. Register April 2005 No. 592, eff. 5-1-05; CR 06-038: cr. (17) Register January 2007 No. 613, eff. 2-1-07.
NR 320.04 NR 320.04 Bridge and culvert clearance over navigable waterway.
NR 320.04(1)(1) New bridges or culverts or replacements of existing bridges and culverts spanning navigable waterways, shall, except as provided in this section, maintain a clearance of not less than 5 feet.
NR 320.04(2) (2) The department may require clearance of more than 5 feet when the waterway has been or is likely to be navigated when it is above its ordinary high water mark elevation or if it is used by watercraft or snowmobiles requiring greater clearance.
NR 320.04(3) (3) The department may allow less than 5 feet of navigation clearance when all of the following apply:
NR 320.04(3)(a) (a) The waterway is known to have little or no navigation or snowmobile use.
NR 320.04(3)(b) (b) The waterway is not anticipated to have navigational use by other than lightweight craft.
NR 320.04(3)(c) (c) The owner provides a portage over or around the bridge or culvert.
NR 320.04(3)(d) (d) The reduced clearance would not be detrimental to the public interest.
NR 320.04 History History: CR 04-084: cr. Register April 2005 No. 592, eff. 5-1-05; CR 06-038: r. (4) and (5) Register January 2007 No. 613, eff. 2-1-07.
NR 320.05 NR 320.05 Bridge enforcement for municipal highway bridges. Upon receipt of written complaint, the department shall investigate the construction or maintenance of any municipal highway bridge. In evaluating complaints, the department shall apply the principles in Capt. Soma Boat Line, Inc. v. City of Wisconsin Dells (56 Wis. 2d 838
NR 320.05(1973)(1973)) to determine what course of action it will follow in the case. The department shall apply the clearance standards in this chapter in determining whether a municipal highway bridge constitutes an obstruction to navigation.
NR 320.05 History History: CR 04-084: cr. Register April 2005 No. 592, eff. 5-1-05.
NR 320.06 NR 320.06 Bridges and culverts.
NR 320.06(1) (1) Exemptions.
NR 320.06(1)(a)(a) Procedures. Exemptions shall be processed according to the procedures in ch. NR 310.
NR 320.06(1)(b) (b) Applicable activities. A replacement of a culvert that meets all the standards in par. (c) shall be exempt under s. 30.123 (6) (e), Stats. A replacement of a previously permitted culvert that meets all the standards in par. (d) shall be exempt under s. 30.123 (6) (d), Stats.
NR 320.06 Note Note: Section 30.123 (6) (e), Stats., was repealed by 2015 Wis. Act 55.
NR 320.06 Note Note: Eligibility for an exemption or general permit does not automatically result in a federal permit or state water quality certification for fill in wetlands. Some projects involving minimal wetland fill may be eligible for authorization under a U.S. Army Corps of Engineers general permit which has already been granted state water quality certification or a general permit under s. 281.36 (3g) (b), Stats. (under development) All other projects affecting wetlands will require individual water quality certification including public notice as required by s. 401, Federal Clean Water Act, and s. 281.36 (3b) (b), Stats., and carried out under chs. NR 103 and 299. For further instructions, see the department's website at under the topic “Waterway and Wetland Permits."
NR 320.06(1)(c) (c) Standards to replace a culvert that does not exceed 24-inches in diameter.
NR 320.06(1)(c)1.1. The culvert may not be located in an area of special natural resource interest, in a public rights feature as described in s. NR 1.06, or in navigable tributaries to surface waters identified as trout streams by the department in s. NR 1.02 (7).
NR 320.06(1)(c)2. 2. The culvert may not exceed 24 inches in diameter, span or width.
NR 320.06(1)(c)3. 3. For a culvert replacement to be considered exempt, the culvert must be in place or documented to have been in place in the past 3 years.
NR 320.06 Note Note: The historical presence of a culvert that is no longer in place or was not in place in the past 3 years does not constitute a replacement.
NR 320.06(1)(c)4. 4. The replacement culvert shall be an in-kind replacement of a single culvert of the same cross-sectional area and of equal or shorter length of culvert that is being replaced.
NR 320.06(1)(c)5. 5. The required culvert area may not exceed 3 square feet as calculated in s. NR 320.07 (1), to ensure that a 24-inch culvert adequately passes stream flow and is not likely to create a ponded condition upstream.
NR 320.06(1)(c)6. 6. Culvert replacement 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 Note Note: A culvert which is part of a structure that functions as a dam requires an approval or permit under ch. 31, Stats.
NR 320.06(1)(c)7. 7. Both ends of the culvert shall be installed so 4 to 6 inches lies below the bed of the waterway.
NR 320.06(1)(c)8. 8. Culvert inlets may not be capped with screens, bars or any other means, with the exception of beaver control procedures, that prevents movement of fish or wildlife or collects debris. Culvert openings shall be inspected at least once a year for debris and any obstructions shall be removed.
NR 320.06(1)(c)9. 9. The culvert 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 be no longer than the sum of the width of the roadtop, the slide slopes, and additional one foot on each side as calculated in s. NR 320.07 (3). The culvert shall extend at least one foot beyond the fill. The channel shall be protected with 3 to 12 inch diameter variable sized riprap extending horizontally at least 2 times the culvert diameter from the end of the culvert. Riprap placement shall include an adequate filter layer or filter fabric.
NR 320.06 Note Note: Prefabricated culvert end sections may be a viable alternative to stabilization with rip rap.
NR 320.06(1)(c)10. 10. Clean fill material shall be firmly compacted around the culvert. The culvert shall be designed or protected to prevent crushing.
NR 320.06(1)(c)11. 11. Dredging under s. 30.20 (1g) (b) 1., Stats., and deposition of sand, gravel or stone on the stream bed under s. 30.12 (1g) (a), Stats., may be associated with the replacement of a culvert provided dredging is limited to the volume necessary to bury the culvert as required in subd. 5. and the deposit is limited to the area immediately underneath or within 2 feet of the culvert.
NR 320.06(1)(c)12. 12. Culvert replacement is prohibited from March 15 to June 1 annually to minimize adverse impacts on fish movement, fish spawning, egg incubation periods and high stream flows. Where emergency replacement is necessary to access an existing residence or agricultural lands, the culvert may be replaced during this time period if construction can be completed within 6 hours.
NR 320.06(1)(c)13. 13. Erosion control measures shall meet or exceed the technical standards for erosion control approved by the department under subch. V of ch. NR 151. Any area where topsoil is exposed during construction shall be immediately seeded and mulched or riprapped to stabilize disturbed areas and prevent soils from being eroded and washed into the waterway.
NR 320.06 Note Note: These standards can be found at the following website:
NR 320.06(1)(c)14. 14. Unless part of a permanent stormwater management system, all temporary erosion and sediment control practices shall be removed upon final site stabilization. Areas disturbed during construction or installation shall be restored.
NR 320.06(1)(c)15. 15. 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. 15. a. to c. or h. Decontamination shall include either subd. 15. 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(1)(c)15.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(1)(c)15.b. b. Drain all water from equipment used in navigable waters.
NR 320.06 Note Note: 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(1)(c)15.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(1)(c)15.d. d. Wash equipment at a temperature of not less than 212 degrees Fahrenheit water (steam clean).
NR 320.06(1)(c)15.e. e. Wash equipment with soap and water or high pressure water of not less than 2000 pounds per square inch.
NR 320.06(1)(c)15.f. f. Allow equipment to dry thoroughly for not less than 5 days.
Published under s. 35.93, Stats. Updated on the first day of each month. Entire code is always current. The Register date on each page is the date the chapter was last published.