NR 116.03(13) (13) “Flood frequency” means the probability of a flood occurrence. A flood frequency is generally determined from statistical analyses. The frequency of a particular flood event is usually expressed as occurring, on the average, once in a specified number of years or as a percent (%) chance of occurring in any given year.

NR 116.03 Note Note: For example, a 100-year flood event is expected to occur, or be exceeded, on the average of once in every 100 years, or which has a 1% chance of occurring or being exceeded in any given year. Any particular flood event could, however, occur more frequently than once in any given year.

NR 116.03(14) (14) “Floodfringe” means that portion of the floodplain outside of the floodway, which is covered by flood water during the regional flood. The term, “floodfringe” is generally associated with standing water rather than flowing water.

NR 116.03(15) (15) “Flood of record” means the highest known flood, the elevation of which can be determined through the use of physical or photographic data.

NR 116.03(16) (16) “Floodplain” means that land which has been or may be covered by flood water during the regional flood. The floodplain includes the floodway, floodfringe, shallow depth flooding, flood storage and coastal floodplain areas.

NR 116.03(17) (17) “Floodplain island” means a natural geologic land formation within the floodplain that is surrounded, but not covered, by flood water during the regional flood.

NR 116.03(18) (18) “Floodplain management” means the full range of public policy and action for insuring wise use of floodplains. It includes everything from the collection and dissemination of flood data to the acquisition of floodplain lands and the enactment and administration of codes, ordinances and statutes for land use in the floodplain.

NR 116.03(19) (19) “Floodproofing” means any combination of structural provisions, changes or adjustments to properties and structures, water and sanitary facilities and contents of buildings subject to flooding, for the purpose of reducing or eliminating flood damage.

NR 116.03(20) (20) “Flood protection elevation” means an elevation 2 feet above the regional flood elevation.

NR 116.03(21) (21) “Flood storage” means those floodplain areas where storage of flood waters has been taken into account in reducing the regional flood discharge.

NR 116.03(22) (22) “Floodway” means the channel of a river or stream, and those portions of the floodplain adjoining the channel required to carry the regional flood discharge.

NR 116.03(23) (23) “Freeboard” means a flood protection elevation requirement designed as a safety factor which is usually expressed in terms of a specified number of feet above a calculated flood level. Freeboard compensates for the effects of many factors that contribute to flood heights greater than those calculated. These factors include, but are not limited to, ice jams, debris accumulation, wave action, obstruction of bridge openings and floodways, the effects of urbanization on the hydrology of the watershed, loss of flood storage areas due to development and aggradation of the river or stream bed.

NR 116.03(24) (24) “Habitable building” means any building, or portion thereof used for human habitation.

NR 116.03(25) (25) “High flood damage potential” means potential damage as a result of flooding that is associated with any danger to life or health or any significant economic loss to a structure or building and its contents.

NR 116.03(26) (26) “Human habitation” means a human residence or dwelling.

NR 116.03(27) (27) “Hydraulic floodway lines” means those lines that delineate those portions of floodplain including the channel which are required to convey the regional flood discharge without any increase in regional flood heights.

NR 116.03(28) (28) “Increase in regional flood height” means a calculated upward rise in the regional flood elevation, equal to or greater than 0.01 foot, resulting from a comparison of existing conditions and proposed conditions which is directly attributable to development in the floodplain but not attributable to manipulation of mathematical variables such as roughness factors, expansion and contraction coefficients and discharge.

NR 116.03(29) (29) “Levee” means a continuous dike or embankment of earth constructed to prevent flooding of certain areas of land.

NR 116.03(30) (30) “Littoral drift” means the movement of sedimentary material along the Lake Michigan or Lake Superior shoreline due to wave action and water currents.

NR 116.03(30m) (30m) “Mobile recreational vehicle” means a recreational vehicle that is carried, towed or self-propelled; is licensed for highway use, if registration is required; and is always capable of being driven or towed by a licensed vehicle.

NR 116.03(31) (31) “Municipality” or “municipal” means a county, city or village.

NR 116.03(32) (32) “NGVD” or “National Geodetic Vertical Datum” means elevations referenced to mean sea level datum, 1929 adjustment.

NR 116.03(33) (33) “Nonconforming building” means an existing lawful building which is not in conformity with the dimensional or structural requirements of the floodplain zoning ordinance for the area of the floodplain which it occupies.

NR 116.03(34) (34) “Nonconforming use” means an existing lawful use or accessory use of a structure, building or development which is not in conformity with the provisions of the floodplain zoning ordinance for the area of the floodplain which it occupies.

NR 116.03(35) (35) “Obstruction to flow” means any development which physically blocks the conveyance of flood waters such that this development by itself or in conjunction with any future similar development will cause an increase in regional flood height.

NR 116.03(36) (36) “Official floodway lines” means those lines which have been approved by the department, adopted by the municipality, and which are shown on the official floodplain zoning maps and used for regulatory purposes. The official floodway lines are established assuming that the area landward of the floodway lines will not be available to convey flood flows.

NR 116.03(37) (37) “Open space use” means a use which has a relatively low flood damage potential, such as uses associated with agriculture, recreation, parking, storage yards, or certain sand and gravel operations.

NR 116.03(38) (38) “Private sewage system” means a sewage treatment and disposal system serving a single structure with a septic tank and soil absorption field located on the same parcel as the structure. This term also means an alternative sewage system approved by the department of industry, labor and human relations including a substitute for the septic tank or soil absorption field, a holding tank, a system serving more than one structure or a system located on a different parcel than the structure.

NR 116.03(39) (39) “Public utilities” means those utilities which employ underground or overhead transmission lines such as electric, telephone and telegraph, and distribution and collection systems such as water, sanitary sewer and storm sewer.