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Glossary of Terms


APPURTENANT STRUCTURE shall mean a structure on the same parcel of property as the principal structure, the use of which is incidental to the use of the principal structure.

BASE FLOOD shall mean the flood having a one percent chance of being equaled or exceeded in magnitude in any given year. (Also knows as the 1% annual chance flood). This is the flooding event that is used to calculate flood risk for the National Flood Insurance Program (NFIP) and the Federal Emergency Management Agency (FEMA).

BASE FLOOD ELEVATION means the height (above sea-level) that flood waters will reach at a given location in the event of the Base (1% annual chance) flooding event.

BASEMENT shall mean any area of the building having its floor subgrade (below ground level) on all sides.

BENCH MARK means a permenant marker or monument of known elevation and horizontal location used for surveying.

BUILDING means a walled and roofed structure, other than a gas or liquid storage tank, that is principally above ground and affixed to a permanent site, including a manufactured (i.e.,mobile) home on a permanent foundation. (See STRUCTURE).

COMMUNITY means a political entity that has the authority to adopt and enforce floodplain ordinances for the area under its jurisdiction.

CONVEYANCE is a measure of the water carrying capacity of a stream reach.

CROSS SECTION (XSEC) means surveyed ground points along a line that shows the geometry of the floodplain and channel.

DEVELOPMENT means any man-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.

DRAINWAY shall mean a depression two feet or more below the land which serves to give direction to a current of water less than nine months of the year, and which has a bed and well-defined banks.(See WATERCOURSE)

EMERGENCY PROGRAM is typically the first phase under which a community participates in the NFIP. It is intended to provide a first layer amount of insurance at subsidized rates to all insurable structures in that community before the effective date of the initial Flood Insurance Rate Map (FIRM).

ENCROACHMENT is any man-made obstruction in the floodplain which displaces the natural passage of flood waters.

EXISTING CONSTRUCTION means (for the purposes of determining flood insurance rates) structures for which the "start of construction" commenced before the effective date of the FIRM or before January 1, 1975, for FIRM's effective before that date. "Existing construction" may also be referred to as "existing structures."

EXISTING MANUFACTURED HOME PARK OR SUB-DIVISION means 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 (including at a minimum, the installation of utilities, the construction of streets, and either final site grading or the pouring of concrete pads) is complete before the effective date of the floodplain management regulations adopted by a community.

EXPANSION OF EXISTING MANUFACTURED HOME PARK OR SUB-DIVISION means the preparation of additional sites by the construction of facilities for servicing the lots on which the manufactured homes are to be affixed (including the installation of utilities, the construction of streets, and either final site grading or the pouring of concrete pads).

FEDERAL EMERGENCY MANAGEMENT AGENCY (FEMA) is an independent federal agency established to respond to emergencies beyond the scope of local and state resources. FEMA administers the US Fire Administration, Office of Strategic Communication and the Federal Insurance Administration which includes the National Flood Insurance Program and the Federal Crime Insurance Program. FEMA operates through ten regional offices who work in partnership with various state and local agencies. FEMA's "Mission" is to provide leadership and support to reduce the loss of life and property and protect the nations institutions from all types of hazards through a comprehensive, risk-based, all-hazards emergency management program of mitigation, preparedness, response and recovery.

FLOOD means a general and temporary condition of partial or complete inundation of normally dry land areas from: (1) The overflow of inland or tidal waters. (2) The unusual and rapid accumulation of runoff of surface water from any source.

FLOOD BOUNDARY AND FLOODWAY MAP is a floodplain management map issued by FEMA that shows, based on detailed and approximate analyses, the boundaries of the 100-year and 500-year floodplains and the 100-year floodway.

FLOOD FRINGE means that portion of the 100-year floodplain outside the floodway in which total encroachment is permissible.

FLOOD HAZARD BOUNDARY MAP (FHBM) is the initial insurance map issued by FEMA that identifies approximate areas of 1% annual chance flood hazard in a community.

FLOOD INSURANCE RATE MAP (FIRM) is the insurance and floodplain management map issued by FEMA that identifies areas of 1% annual chance flood hazard in a community. In some areas, the map also shows base flood elevations and 500-year floodplain boundaries and occasionally, regulatory floodway boundaries.

FLOOD INSURANCE STUDY (FIS) is an engineering study performed by FEMA to identify flood hazard areas, flood insurance risk zones, and other flood data in a community.

FLOODPLAIN means any land area susceptible to inundation by floodwaters from any source.

FLOODPLAIN MANAGEMENT is the operation of an overall program of corrective and preventive measures for reducing flood damage, including but not limited to, emergency preparedness plans, flood control work, and floodplain management regulations.

FLOODPROOFING means 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, structures and their contents.

FLOODWAY means the channel of a river or watercourse and the adjacent land areas that must be reserved in order to discharge the 1% annual chance flood without cumulatively increasing the water surface elevation more than one foot. Floodways are only delineated in commuties where detailed hydraulic analyses have been completed.

GAGING STATION is a particular site on a stream, river, canal, lake or reservoir where systematic observations of gage height or discharge are collected.

HISTORIC STRUCTURE means any structure that is: (a) Listed individully in the National Register of Historic Places (a listing maintained by the Department of Interior) or preliminarily determined by the Secretary of the Interior as meeting the requirements for individual listing on the National Register; (b) Certified or preliminarily determined by the Secretary of the Interior as contributing to the historical significance of a registered historic district or a district preliminarily determined by the Secretary to qualify as a registered historic district; (c) Individually listed on a state inventory of historic places in states with historic preservation programs which have been approved by the Secretary of the Interior; or (d) Individually listed on a local inventory of historic places in communities with historic preservation programs that have been certified either: (1) By an approved state program as determined by the Secretary of the Interior or (2) Directly by the Secretary of the Interior in states without approved programs.

HYDRAULICS is a branch of engineering dealing primarily with the flow of water and the application of fluid mechanics principles.

HYDROLOGY is a science dealing with the properties, distribution and circulation of water on the surface, below the ground and in the atmosphere.

LETTER OF MAP AMENDMENT (LOMA) is the result of an administrative procedure in which the Federal Insurance Administrator reviews scientific or technical data submitted by the owner or lessee of property who believes the property has incorrectly been included in a designated special flood hazard area (SFHA). A LOMA amends the currently effective FEMA map and establishes that a property is not located in a SFHA.

LETTER OF MAP REVISION (LOMR) is an official revision to the currently effective FEMA map. It is used to change flood zones, floodplain and floodway delineations, flood elevations, and planimetric features. All requests for LOMRs must be made to FEMA through the chief executive officer of the community, since it is the community that must adopt any changes and revisions to the map.

LETTER OF MAP REVISION BASED ON FILL (LOMR-F) is an official revision to a currently effective FEMA map to remove a parcel of land from the floodplain by the placement of compacted fill to elevate the surface of the ground to or above the base flood elevation at that location. (See LETTER OF MAP REVISION)

LOWEST FLOOR shall mean the lowest floor of the lowest enclosed area (including basement). An unfinished or floodresistant enclosure, usable solely for parking of vehicles, building access or storage, in an area other than a basement area, is not considered a building's lowest floor, provided that such enclosure is not built so as to render the structure in violation of the applicable non-elevation design requirements of the State of Nebraska Minimum Standards for Floodplain Management.

MANDATORY PURCHASE means under the provisions of the Flood Disaster Protection Act of 1973, individuals, businesses, and others buying, building, or improving property located in identified areas of special flood hazards within participating communities are required to purchase flood insurance as a prerequisite for receiving any type of direct or indirect federal financial assistance (e.g., any loan, grant, guaranty, insurance, payment, subsidy, or disaster assistance) when the building or personal property is the subject of or security for such assistance.

MANUFACTURED HOME shall mean a structure, transportable in one or more sections, which is built on a permanent chasis and is designed for use with or without a permanent foundation when attached to the required utilities. The term "manufactured home" does not include a "RECREATIONAL VEHICLE."

MANUFACTURED HOME PARK OR SUBDIVISION shall mean a parcel (or contiguous parcels) of land divided into two or more manufactured home lots for rent or sale.

NATIONAL GEODETIC VERTICAL DATUM (NGVD) is the National standard reference datum for elevations, formerly referred to as Mean Sea Level (MSL) of 1929. NGVD is used as the reference datum on most FIRMs.

NATURAL GRADE means the grade unaffected by construction techniques such as fill, landscaping, or berming.

NEW CONSTRUCTION shall mean obstructions for which the "start of construction" commenced on or after the effective date of the floodplain management regulation adopted by a community and includes any subsequent improvements to such obstructions.

NON-RESIDENTIAL includes, but is not limited to: small business concerns, churches, schools, nursing homes, farm buildings (including grain bins and silos), poolhouses, clubhouses, recreational buildings, government buildings, mercantile structures, agricultural and industrial structures, warehouses, and hotels or motels with normal room rentals for less than 6 months' duration.

OBSTRUCTION shall mean any wall, wharf, embankment, levee, dike, pile, abutment, projection, excavation (including the alteration or relocation of a watercourse or drainway), channel rectification, bridge, conduit, culvert, building, stored equipment or material, wire, fence, rock, gravel, refuse, fill, or other analogous structure or matter which may impede, retard, or change the direction of flow of water, either in itself or by catching or collecting debris carried by such water, or that is placed where the natural flow of the water would carry such structure or matter downstream to the damage or detriment of either life or property. Dams designed to store or divert water are not obstructions if permission for the construction thereof is obtained from the Department of Water Resources pursuant to section 46-257.

OTHER RESIDENTIAL means hotels or motels where the normal occupancy of a guest is 6 months or more; a tourist home or rooming house which has more than 4 roomers. A residential building (excluding hotels and motels with normal room rentals for less than 6 months' duration and containing more than 4 dwelling units) is permitted incidental office, professional private school, or studio occupancy, provided that the total area of such occupancy is limited to less than 25 percent of the total floor area within the building.

100-YEAR DISCHARGE is the volume rate of streamflow (usually expressed in cubic feet per second) having a 100-year frequency of recurrence. This discharge magnitude is based on statistical analysis of stream flow records and analysis of rainfall and runoff characteristics in a particular watershed.

100-YEAR FLOOD (also called the Base Flood) is the flood having a one percent chance of being equalled or exceeded in magnitude in any given year. Contrary to popular belief, it is not a flood occurring once every 100 years.

100-YEAR FLOODPLAIN The area adjoining a river, stream, or watercourse covered by water in the event of a 100-year flood.

100-YEAR FREQUENCY means a recurrence interval averaging 100 years. It can also be stated as having a one percent probability of occuring in any given year.

OVERBANK; LEFT AND RIGHT is the floodplain which lies to the left and right, respectively, of the watercourse as one looks downstream.

PHYSICAL MAP REVISION is an official republication of a map to effect changes to flood insurance zones, floodplain delineations, flood elevations, floodways and planimetric features. These changes typically occur as a result of structural works or improvements, annexations resulting in additional flood hazard ares, or corrections of base flood elevations or flood insurance risk zones.

POST-FIRM CONSTRUCTION is construction or substantial improvement which started on or after the effective date of the initial Flood Insurance Rate Map (FIRM) of the community or after December 31, 1974, whichever is later.

PRE-FIRM CONSTRUCTION is construction or substantial improvement which started on or before December 31, 1974, or before the effective date of the initial Flood Insurance Rate Map (FIRM) of the community, whichever is later.

PRINCIPALLY ABOVE GROUND shall mean that at least 51 percent of the actual cash value of the structure is above ground.

PROBATION is a means of formally notifying participating communities of violations and deficiencies in the administration and enforcement of the local floodplain management regulations. A community is placed on probation for one year (may be extended) during which time a surcharge is applied to all NFIP policies issued on or after the Probation Surcharge effective date. Probation is terminated if deficiencies are corrected. If a community does not take remedial or corrective measures while on probation, it can be suspended.

REACH means a continuous segment of a watercourse.

RECREATIONAL VEHICLE shall mean a vehicle which is (i) built on a single chasis; (ii) 400 square feet or less when measured at the largest horizontal projections; (iii) designed to be self-propelled or permanently towable by a light duty truck; and (iv) designed primarily not for use as a permanent dwelling but as temporary living quarters for recreational, camping, travel, or seasonal use.

REGULAR PROGRAM is the phase of a community's participation in the NFIP where more comprehensive floodplain management requirements are imposed and higher amounts of insurance are available based upon risk zones and elevations determined in a flood insurance study. The Flood Insurance Rate Map is the map used in this phase of the NFIP.

REGULATORY FLOOD ELEVATION in Nebraska means the Base Flood Elevation plus one foot of freeboard which is required to meet the Minimum Standards for Floodplain Management in the State of Nebraska.

REPALCEMENT COST means the cost to replace property with the same kind of material and construction without deduction for depreciation.

ROUGHNESS COEFFICIENT (Manning's) is a measure of ground surface roughness used in flow equations.

SHEET FLOOD HAZARD is a type of flood hazard with flooding depths of 1 to 3 feet that occurs in areas of sloping land. The sheet flow hazard is represented by the zone designation AO on the Flood Insurance Rate Map (FIRM).

SPECIAL FLOOD HAZARD AREA is the darkly shaded area on the Flood Hazard Boundary Map (FHBM) or Flood Insurance Rate Map (FIRM) which identifies an area that has a one percent chance of being flooded in any given year (100-year floodplain). The FIRM identifies these shaded areas as FIRM Zones A, AO, AH, A1-A30, AE, A99, V, V1-30, and VE.

START OF CONSTRUCTION shall mean the date the building permit was issued, provided the actual start of construction, repair, reconstruction, rehabilitation, addition, placement, or other improvement was within 180 days of the permit date. "Start of construction" includes substantial improvements. The actual start means the first placement of permanent construction of a structure on a site, such as the pouring of slab or footings. the installation of piles, the construction of columns, or any work beyond the stage of excavation; or the placement of a manufactured home on a foundation. Permanent construction does not include land preparation, such as clearing, grading and filling; nor does it include the installation of streets and/or walkways; nor does it include excavation for a basement, footings, piers, or foundations or the erection of temporary forms; nor does it include the installation on the property of accessory buildings, such as garages or sheds not occupied as dwelling units or not part of the main structure. For a substantial improvement, the actual start of construction means the first alteration of any wall, ceiling, floor, or other structural part of a building, whether or not the alteration affects the external dimensions of the building.

STAGE is the elevation of surface water above a reference datum, that datum usually being near the stream bed.

STRUCTURE shall mean a walled and roofed building that is principally above ground, as well as a manufactured home, and a gas or liquid storage tank that is principally above ground.(See BUILDING)

SUBSTANTIAL DAMAGE shall mean a damage of any origin sustained by an obstruction whereby the cost of restorating the obstruction to its before-damage condition would equal or exceed 50 percent of the market value of the obstruction before the damage occurred.

SUBSTANTIAL IMPROVEMENT shall mean any reconstruction, rehabilitation, addition, or other improvement of an obstruction, the cost of which equal or exceed 50 percent of the market value of the obstruction before "start of construction" of the improvement. This includes obstructions which have incurred "substantial damage," regardless of the actual repair work performed. The term does not, however, include either (1) any project for improvement of a structure or other obstruction to correct existing violations of state or local health, sanitary, or safety code specifications which have been identified by the local code enforcement official and which are the minimum necessary to assure safe living conditions, or (2) any alteration of a "historic structure," provided that the alteration will not preclude the structure's continued designation as a "historic structure."

SURCHARGE means an increase in flood elevation due to destruction of the floodplain that reduces it's conveyance capacity.

SUSPENSION means the removal of a participating community from the National Flood Insurance Program (NFIP) because the community has not enacted and/or enforced the proper floodplain management regulations required for participation in the National Flood Insurance Program (NFIP).

VARIANCE is a grant of relief to a person from the requirements of Floodplain Management Standards which permits construction in a manner otherwise prohibited by ordinance where specific enforcement would result in unnecessary hardship. The granting of a variance does not remove the requirements for flood insurance which lending institutions will require if the structure is the collateral of a loan. Flood insurance rates will be much higher for structures built below the Base Flood Elevation.

VIOLATION means a failure of a structure or other development to be fully compliant with the community's floodplain management regulations.

WATERCOURSE shall mean any depression two feet or more below the surrounding land which serves to give direction to a current of water at least nine months of the year and which has a bed and well-defined banks. (See DRAINWAY)

WATERSHED (also called a Drainage Basin). It is that area of land which may contribute flow from runoff to a particular watercourse.

WATER SURFACE PROFILE (also referred to as Flood Elevation Profile) means a graph showing the relationship of water surface elevation to location, the latter generally expressed as a distance upstream from some reference point.

WETLANDS are transitional areas between open water and dry land. The water may not be on the surface at all times making it hard to recognize. Wetlands are generally extremely valuable and productive ecosystems.

WRITE YOUR OWN (WYO) PROGRAM is a cooperative undertaking of the insurance industry and the Federal Insurance Administration begun in October 1983. The WYO Program operates within the context of the NFIP and involves private insurance carriers who issue and service National Flood Insurance Program policies.

ZONE A (UNNUMBERED) are Special Flood Hazard Areas subject to inundation from the 100-Year flood. Because detailed hydraulic analyses have not been performed, no base flood elevations or depths are shown. Mandatory flood insurance purchase requirements apply.

ZONE AE and A1-30 are Special Flood Hazard Areas subject to inundation by the 100-Year flood determined in a Flood Insurance Study by detailed methods. Base flood elevations are shown within these zones. Mandatory flood insurance purchase requirements apply. (Zone AE is used on new and revised maps in place of Zones A1-30.)

ZONE AH are Special Flood Hazard Areas subject to inundation by 100-Year shallow flooding (usually areas of ponding) where average depths are between one and three feet. Base flood elevations derived from detailed hydraulic analyses are shown in this zone. Mandatory flood insurance purchase requirements apply.

ZONE AO are Special Flood Hazard Areas subject to inundation by 100-Year shallow flooding (usually sheet flow on sloping terrain) where average depths are between one and three feet. Average flood depths derived from detailed hydraulic analyses are shown within this zone. Mandatory flood insurance purchase requirements apply.

ZONE B, C, and X are areas that have been identified in the community flood insurance study as areas of moderate or minimal hazard from principal source flood in the area. However, buildings in these zones could be flooded by severe, concentrated rainfall coupled with inadequate local drainage systems. Flood Insurance is available in participating communities but is not required by regulation in these zones. (Zone X is used on new and revised maps in place of Zones B and C.)

ZONE D are unstudied areas where flood hazards are undetermined by flooding is possible. No mandatory flood insurance purchase requirements apply, but coverage is available in participating communities.

ACRONYMS


BFE- Base Flood Elevation

COE- Corps of Engineers (Same as USACE)

FBFM- Flood Boundary and Floodway Map

FEMA- Federal Emergency Management Agency

FHBM- Flood Hazard Boundary Map

FIA- Federal Insurance Administration

FIRM- Flood Insurance Rate Map

GIS- Geographic Information System

GPS- Global Positioning Systems

LOMA- Letter of Map Amendment

LOMR- Letter of Map Revision

NAVD '88- North America Vertical Datum 1988

NFIP- National Flood Insurance Program

NGVD '29- National Geodetic Vertical Datum 1929

NRD- Natural Resources District

SFHA- Special Flood Hazard Area

USACE- U. S. Army Corps of Engineers

USGS- U. S. Geological Society

WYO- Write Your Own

 

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