For the purpose of this chapter, the following definitions shall apply unless the context clearly indicates or requires a different meaning.
100-YEAR FLOOD. One percent annual chance flood. See BASE FLOOD.
ACCESSORY USE OR STRUCTURE. A structure or use that is secondary but related to the primary structure or use permitted in these regulations (e.g., a picnic shelter would be accessory to a campground).
ACT. Montana Floodplain and Floodway Management Act, MCA §§ 76-5-101 through 76-5-406.
APPEAL. A request for a review of the Floodplain Administrator’s interpretation of any provisions of these regulations or a request for a variance.
APPLICANT. A person, or a person’s agent, who submits an application as required by these regulations.
AREA OF SHALLOW FLOODING. A designated AO, AH, AR/AO, AR/AH, or VO zone on the Flood Insurance Rate Map (FIRM) with a 1% or greater annual chance of flooding to an average depth of one to three feet where a clearly defined channel does not exist, where the path of flooding is unpredictable, and where velocity flow may be evident. Such flooding is characterized by ponding or sheet flow.
AREA OF SPECIAL FLOOD HAZARD. The land in a mapped or identified floodplain within a community subject to inundation by a 1% or greater chance of flooding in any given year (i.e., the 100- year floodplain).
ALTERATION. Any change or addition to an artificial obstruction that either increases its external dimensions or increases its potential flood hazard.
(ARM § 36.15.101(2))
APPURTENANT STRUCTURE. A structure in which the use is incidental or accessory to the use of a principal structure.
(44 C.F.R. § 59.1)
ARTIFICIAL OBSTRUCTION. Any obstruction which is not natural and includes any development, dam, diversion, wall, riprap, embankment, levee, dike, pile, abutment, projection, revetment, excavation, channel rectification, road, bridge, conduit, culvert, building, refuse, automobile body, fill, or other analogous structure or matter in, along, across, or projecting into any regulated flood hazard area that may impede, retard, or change the direction of the flow of water, either in itself or by catching or collecting debris carried by the water, or that is placed where the natural flow of the water would carry the same downstream to the damage or detriment of either life or property. See also DEVELOPMENT.
(ARM § 36.15.101(3)) (MCA § 76-5-103(1))
BASE FLOOD (FLOOD OF 100-YEAR FREQUENCY). A flood having a 1% chance of being equaled or exceeded in any given year.
(ARM § 36.15.101(4)) (44 C.F.R. § 59.1)
BASE FLOOD ELEVATION (BFE). The elevation above sea level of the base flood in relation to the National Geodic Vertical Datum of 1929 or the North American Vertical Datum of 1988 or unless otherwise specified.
(ARM § 36.15.101(5))
BASEMENT. Any area of a building, except a crawl space, as having its lowest floor below ground level on all sides.
(44 C.F.R. § 59.1) (NFIP Insurance Manual, Rev. April 2021)
BUILDING. A walled and roofed structure, including a gas or liquid storage tank that is principally above ground, as well as a manufactured home.
(44 C.F.R. § 59.1)
CHANNEL. The geographical area within either the natural or artificial banks of a watercourse or drain way.
(MCA § 76-5-103(2))
CRAWL SPACE. An enclosure that has its interior floor area no more than five feet below the top of the next highest floor. See ENCLOSURE and SUBGRADE CRAWLSPACE.
(NFIP Insurance Manual, Rev. April 2021)
DNRC. The state’s Department of Natural Resources and Conservation.
DESIGNATED FLOODWAY. A floodway whose limits have been designated and established by order of the Department of Natural Resources and Conservation, state, or Federal Emergency Management Agency.
DEVELOPMENT. Any human-made change to improved or unimproved real estate, including, but not limited to, buildings or other structures, mining, dredging, filling, grading, paving, excavation, or drilling operations or storage of equipment or materials. See also ARTIFICIAL OBSTRUCTION.
(44 C.F.R. § 59.1)
ELEVATED BUILDING. A building that has no basement and that has it lowest elevated floor raised above ground level by foundation walls, shear walls, posts, piers, pilings, or columns. A building on a crawlspace is considered an ELEVATED BUILDING.
(NFIP Insurance Manual, Rev. April 2021)
ENCLOSURE. That portion below the lowest elevated floor of an elevated building that is either partially or fully shut in by rigid walls including a crawlspace, subgrade crawlspace, stairwell, elevator, or a garage below or attached.
ENCROACHMENT. Activities or construction within the regulated flood hazard area, including fill, new construction, substantial improvements, and other development.
ENCROACHMENT ANALYSIS. A hydrologic and hydraulic analysis performed by an engineer to assess the effects of the proposed artificial obstruction or nonconforming use on base flood elevation, flood flows, and flood velocities.
ESTABLISH. To construct, place, insert, or excavate.
(ARM § 36.15.101(9)) (MCA § 76-5-103(7))
EXISTING ARTIFICIAL OBSTRUCTION or NONCONFORMING USE. An artificial obstruction or nonconforming use that was established before land use regulations were adopted pursuant to MCA § 76-5-301(1).
(MCA 76-5-404(3))
FEMA. Federal Emergency Management Agency.
FLOOD FRINGE. The identified portion of the floodplain of the regulated flood hazard area outside the limits of the floodway.
(ARM § 36.15.101(10))
FLOOD INSURANCE STUDY. The report in which FEMA has provided flood profiles, as well as the flood boundary/floodway map and the water surface profiles.
FLOOD OF 100-YEAR FREQUENCY (BASE FLOOD). A flood magnitude expected to recur on the average of once every 100-years or a flood magnitude that has a 1% chance of occurring in any given year.
(44 C.F.R. § 59.1) (MCA § 76-5-103(9))
FLOOD OF 100-YEAR PROOFING. Any combination of structural and non-structural additions, changes, or adjustments to structures which reduce or eliminate flood damage to real estate or improved real property, water and sanitary facilities, electrical, plumbing, HVAC systems, structures, and their contents. The term includes wet flood proofing, dry flood proofing, and elevation of structures.
(44 C.F.R. § 59.1)
FLOODPLAIN. The area of the regulated flood hazard area including and adjoining the watercourse or drainway that would be covered by the floodwater of a base flood. The area is partitioned into a flood fringe and floodway where specifically designated. See REGULATED FLOOD HAZARD AREA.
FLOODPLAIN ADMINISTRATOR. Community official or representative appointed to administer and implement the provisions of this chapter.
FLOODWAY. The identified portion of the floodplain of the regulated flood hazard area that is the channel and the area adjoining the channel that is reasonably required to carry the discharge of the base flood without cumulatively increasing the water surface by more than one-half foot.
(MCA §§ 76-5-103(5) and 76-5-103(11))
FREEBOARD. A factor of safety usually expressed in feet above a flood level for purposes of floodplain management. FREEBOARD tends to compensate for the many unknown factors that could contribute to flood heights greater than the height calculated for a selected size flood and floodway conditions, such as wave action, bridge openings, and the hydrological effect of urbanization of the watershed.
HIGHEST ADJACENT GRADE. The highest natural elevation of the ground surface prior to construction next to the proposed walls of a structure. Elevation certificates must also show the elevation of the highest grade adjacent to a proposed development for flood insurance purposes.
HVAC. Heating, ventilating, and air conditioning.
HYDRAULICS. The depth of water (elevation) in a drainage way, watercourse, river, or stream channel.
HYDROLOGY. The discharge in cubic feet per second (CFS) of water in a drainage way, watercourse, river, or stream channel.
LETTER OF MAP CHANGE (LOMC). An official response from FEMA that amends or revises the FEMA Special Flood Hazard Area and FEMA Flood Insurance Study for flood insurance purposes and/or flood risk hazard. FEMA LETTERS OF MAP CHANGE specific to an amendment or revision include.
(1) LETTER OF MAP AMENDMENT (LOMA). A letter of determination from FEMA issued in response to a request that a property or structure is not subject to the mandatory flood insurance requirement because it was inadvertently located in the effective FEMA special flood hazard area. The material submitted and response from FEMA may be considered by the Floodplain Administrator for determining if a property or structure is within the regulated flood hazard area and subject to these regulations.
(2) LETTER OF MAP REVISION BASED ON FILL (LOMR-F). A letter of approval from FEMA removing the mandatory requirement for flood insurance on property based on placement of fill or an addition. Placement of fill or an addition must be preceded by a permit pursuant to these regulations. Placement of fill does not remove the development from the regulated flood hazard area or these regulations.
(3) LETTER OF MAP REVISION (LOMR). An official FEMA amendment to the currently effective FEMA Flood Insurance Rate Map or FEMA Flood Boundary Map based on a physical change to the floodplain of the special flood hazard area. It is issued by FEMA and changes flood zones, delineations, and elevations on the FEMA Flood Insurance Rate Map or FEMA Flood Boundary Map and may amend the FEMA Flood Insurance Study. It must be preceded by an approved alteration of the designated floodplain from DNRC and subsequently an amendment to the regulated flood hazard area.
(4) CONDITIONAL LETTER OF MAP REVISION (CLOMR). A FEMA letter of approval for a proposed physical change that, when completed, would propose to change the flood zones, delineation, or elevations on the FEMA Flood Insurance Rate Map or FEMA Flood Boundary Map and may amend the FEMA Flood Insurance Study through a subsequent LOMR. The CLOMR may be considered in an evaluation by DNRC and the Floodplain Administrator during consideration of a proposed alteration to the regulated flood hazard area.
LEVEE. A human-made embankment, usually earthen, designed and constructed in accordance with the commonly accepted engineering practices to contain, control, or divert the flow of water to provide protection from temporary flooding. For a LEVEE structure to be reflected on the FEMA FIRMs as providing flood protection, the LEVEE structure must meet the requirements set forth in 44 C.F.R. § 65.10.
LOWEST FLOOR. Any floor of a building including a basement used for living purposes, storage, or recreation. This includes any floor that could be converted to such a use.
(ARM § 36.15.101(14)) (44 C.F.R. § 59.1)
MAINTENANCE. Customary and historical cleaning and removal of silt, branches, trees, stock, and other debris as well as minor repair or restoration of an existing structure or artificial obstruction to the size, shape, position, and height it had immediately prior to its deterioration.
MANUFACTURED HOME PARK OR SUBDIVISION. Includes the construction of facilities for servicing the manufactured home lots and, at a minimum, includes the installation of utilities, the construction of streets, and either final site grading or the pouring of concrete pads.
(44 C.F.R. § 59.1)
MANUFACTURED OR MOBILE HOME. A building that may be residential or non-residential, is transportable in one or more sections, built on a permanent chassis, and designed to be used with or without a permanent foundation when connected to the required utilities and includes park trailers, travel trailers, and other similar vehicles placed on a site for greater than 180 consecutive days.
(ARM § 36.15.101(15))
NATURAL OBSTRUCTION. Any rock, tree, gravel, or analogous natural matter that is an obstruction and has been located within the floodplain or floodway by a non-human cause.
NEW CONSTRUCTION. Structures for which the commencement of clearing, grading, filling, or excavating to prepare a site for construction occurs on or after the effective date of these regulations and includes any subsequent improvements to such structures.
(ARM § 36.15.101(20)) (44 C.F.R. § 59.1)
NEW MANUFACTURED HOME PARK OR SUBDIVISION. A MANUFACTURED HOME PARK OR SUBDIVISION for which the construction of facilities for servicing the lots on which the manufactured homes are to be affixed, includes, at a minimum, the installation of utilities, the construction of streets, and either final site grading or the pouring of concrete pads and is completed on or after the effective date of floodplain management regulations adopted by a community.
(44 C.F.R. § 59.1)
NON-CONFORMING STRUCTURE. Any structure that does not conform to the standards or permitting requirements established under these regulations. NON-CONFORMING STRUCTURES may be grandfathered under these regulations, but alternations or changes in use are not grandfathered.
NON-CONFORMING USE. A land use within a mapped or designated floodplain not in accordance with these regulations.
NON-RESIDENTIAL. Buildings including manufactured homes that are not residential, including commercial, agricultural, industrial buildings, and accessory buildings. See RESIDENTIAL.
OWNER. Any person who has dominion over, control of, or title to an artificial obstruction.
(MCA § 76-5-103(13))
PERSON. Includes any individual or group of individuals, corporation, partnership, association, or any other entity, including state and local governments and agencies.
(44 C.F.R. § 59.1)
RECREATIONAL VEHICLE. A park trailer, travel trailer, or other similar vehicle which is:
(1) Built on a single chassis;
(2) Four hundred square feet or less when measured at the largest horizontal projections;
(3) Designed to be self-propelled or permanently towable by a motorized vehicle; and
(4) Designed primarily for use as temporary living quarters for recreation, camping, travel, or seasonal use, not for use as a permanent dwelling.
(44 C.F.R. § 59.1)
REGULATED FLOOD HAZARD AREA. A floodplain whose limits have been designated pursuant to MCA Title 76, Chapter 5, part 2, and is determined to be the area adjoining the watercourse that would be covered by the floodwater of a base flood. The REGULATED FLOOD HAZARD AREA consists of the floodway and flood fringe where specifically designated.
(ARM § 36-15-101(11)) (MCA §§ 76-5-103(4) and 76-5-103(10))
RESIDENTIAL BUILDING. A dwelling or building for living purposes or place of assembly or permanent use by human beings and including any mixed use of residential and non-residential use. All other buildings are non-residential.
RIPRAP. Stone, rocks, concrete blocks, or analogous materials that are placed along the bed or banks of a watercourse or drainway for the purpose of preventing or alleviating erosion.
(ARM § 36.15.101(18))
SCOUR DEPTH. The maximum depth of streambed scour caused by erosive forces of the base flood.
SPECIAL FLOOD HAZARD AREA. Land area which has been specifically identified by the Federal Emergency Management Agency as the floodplain within a community subject to a 1% or greater chance of flooding in any given year. It is useful for the purposes of identifying flood hazards by local subdivisions of government for regulatory purposes as well as use by the National Flood Insurance Program for establishing risk zones and flood insurance premium rates. The FEMA flood hazard area zone designation or flood risk potential is as illustrated on FEMA’s Flood Hazard Boundary Map or Flood Insurance Rate Map.
STRUCTURE. Any artificial obstruction.
SUBGRADE CRAWLSPACE. A crawlspace foundation enclosure that has its interior floor no more than five feet below the top of the next higher floor and no more than two feet below the lowest adjacent grade on all sides. A foundation exceeding either dimension is a basement.
(NFIP Insurance Manual, Rev. April 2021)
SUBSTANTIAL DAMAGE. Damage of any origin sustained by a structure whereby the cost of restoring the structure to its before-damaged condition would exceed 50% of the market value of the structure before the damage occurred.
(44 C.F.R. § 59.1)
SUBSTANTIAL IMPROVEMENT. Any repair, reconstruction, or improvement of a structure where the cost equals or exceeds 50% of the market value of the structure either before the improvement or repair is started or if the structure has been damaged and is being restored, before the damage occurred.
(1) SUBSTANTIAL IMPROVEMENT is considered to occur when the first construction of any wall, ceiling, floor, or other structural part of the building commences.
(2) The term does not include:
(a) Any project for improvement of a structure to comply with existing state or local health, sanitary, or safety code specifications which are solely necessary to assure safe living conditions; or
(b) Any alteration of a structure listed on the national register of historic places or state inventory of historic places.
(ARM § 36.15.101(21)) (44 C.F.R. § 59.1)
SUITABLE FILL. Fill material which is stable, compacted, well graded, and pervious, not adversely affected by water and frost, devoid of trash or similar foreign matter, tree stumps or other organic material; and is fitting for the purpose of supporting the intended use and/or permanent structure.
(ARM § 36.15.101(22))
(ARM § 36.15.101(23))
VIOLATION. A finding and order pursuant to the regulations against the owner or responsible party of the failure of a structure or other development to be fully compliant with these regulations.
(44 C.F.R. § 59.1)
(Ord. 484, passed 5-20-2015)