Wisconsin Administrative Code
Department of Natural Resources
NR 300-399 - Environmental Protection - Water Regulation
Chapter NR 320 - Bridges And Culverts In Or Over Navigable Waterways
Section NR 320.03 - Definitions

(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.

Note: "Area of special natural resource interest" means any of the following:

(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.

(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.

(4) "Channel" means a natural or artificial water course with defined bed and banks to confine and conduct the normal flow of water.

(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.

(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.

(7) "Department" means the department of natural resources.

(8) "Highway" or "public highway" has the meaning in s. 340.01(22), Stats.

(9) "Maintain" means to repair, replace, own or possess all or a portion of a structure.

(10) "Municipal highway bridge" means any city, town, village or county owned structure built in or over a navigable waterway for public highway purposes.

(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.

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).

(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.

(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.

(14) "Professionally engineered" means designed by a person registered as a professional engineer under s. 443.04, Stats., and ch. A-E 4.

(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.

(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.

(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.