# A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
90-Day Appeal Period
Time period when community officials or individual property owners may submit formal objections to information shown on preliminary Flood Insurance Rate Map (FIRM) panels and/or Flood Insurance Study (FIS) Report to the Federal Emergency Management Agency (FEMA) and the Kentucky Division of Water (KDOW), through the local Floodplain Administrator.
1-percent annual chance floodplain
This is the boundary of the flood that has a 1-percent chance of being equaled or exceeded in any given year. Also known as the 100-year floodplain.
1-percent annual chance water-surface elevation
The height, in relation to the National Geodetic Vertical Datum of 1929 (or other datum, where specified), of the flood having a 1-percent chance of being equaled or exceeded in any given flood year (also known as the 100-year flood or the base flood).
100-year flood
The flood having a 1-percent chance of being equaled or exceeded in any given year; also known as the base flood. The 1-percent annual chance flood, which is the standard used by most Federal and state agencies, is used by the National Flood Insurance Program (NFIP) as the standard for floodplain management and to determine the need for flood insurance. A structure located within a special flood hazard area shown on an NFIP map has a 26 percent chance of suffering flood damage during the term of a 30-year mortgage.
100-year floodplain
This is the boundary of the flood that has a 1-percent chance of being equaled or exceeded in any given year. Officially termed the 1-percent annual chance floodplain.
500-year floodplain
This is the boundary of the flood that has a 0.2-percent chance of being equaled or exceeded in any given year. Officially termed the 0.2-percent annual chance floodplain.
A
Approximate Study
A flood hazard study that results in the delineation of floodplain boundaries for the 1-percent annual chance flood, but does not include the determination of BFEs or flood depths. Associated with Zone A on the FIRM.
B
Base Flood
The flood having a 1-percent chance of being equaled or exceeded in any given year; also known as the 100-year flood. The base flood, which is the standard used by most Federal and state agencies, is used by the National Flood Insurance Program (NFIP) as the standard for floodplain management and to determine the need for flood insurance. A structure located within a special flood hazard area shown on an NFIP map has a 26 percent chance of suffering flood damage during the term of a 30-year mortgage.
Base Flood Elevation (BFE)
The elevation of a flood having a 1-percent chance of being equaled or exceeded in any given year.
C
Channel Bank Stations
Points that identify the extreme limits of the natural stream channel. These stations are typically assigned at locations along a cross section where a relatively flat area exists outside of the channel.
Community Rating System (CRS)
Program that recognizes a community’s efforts beyond the minimum National Flood Insurance Program standards by reducing flood insurance premiums for the community’s property owners. Under the CRS, flood insurance premium rates are adjusted to reflect the reduced flood risk resulting from community activities that meet the three goals of the CRS: (1) reduce flood losses; (2) facilitate accurate insurance rating and (3) promote the awareness of flood insurance.
Compliance Period
The period that begins with the issuance of a Letter of Final Determination and ends when a new or revised FIRM becomes effective. During the compliance period, a community must enact and adopt new or revised Flood Damage Prevention Ordinances required for participation in the NFIP.
Cooperating Technical Partner (CTP) Program
The Kentucky Division of Water, FEMA, and numerous other Federal, State, and local agencies have entered into a CTP agreement that formalizes their contribution and commitment to floodplain mapping. Under the agreement, the State has assumed primary ownership of, and responsibility for, the National Flood Insurance Program Flood Insurance Rate Maps for all Kentucky communities. Benefits of this partnership include an opportunity to share resources, maximize limited funding, and take advantage of training and mentoring opportunities.
Cross Section
A line developed from topographic information across a floodplain at which a computation of flood flow has been made to establish a potential flood elevation. Cross sections are shown on the Flood Boundary Floodway Map, Flood Insurance Rate Map, and/or Flood Profiles of a Flood Insurance Study.
Cubic feet per second (cfs)
Typical units used to express the rate of flow of surface water in open channels. One cubic foot is approximately equal to 7.5 gallons per second.
D
Depth
Maximum depth of water in the cross section as measured below the water-surface elevation.
Detailed Study
A flood hazard study that, at a minimum, results in the delineation of the floodplain boundaries for the 1-percent-annual-chance (100-year) flood and the determination of base flood elevations (BFEs) or flood depths.
Digital Elevation Model
A DEM is a file with terrain elevations recorded for the intersection of a fine-grained grid and organized by quadrangle as the digital equivalent of the elevation data on a topographic base map.
Digital Orthophoto
Quadrangle (DOQ)
A DOQ is a digital image of an aerial photograph in which displacements caused by camera orientation and terrain have been removed. These products combine the image characteristics of a photograph with the geometric qualities of a map and can be used in numerous applications either alone or in combination with other digital data.
Digital Flood Insurance Rate Map (DFIRM)
A Flood Insurance Rate Map (FIRM) that has been prepared as a digital product, which may involve converting an existing manually produced FIRM to digital format, or creating a product from new digital data sources using a Geographic Information System environment. The DFIRM product allows for the creation of interactive, multi-hazard digital maps. Linkages are built into an associated database to allow users options to access the engineering backup material used to develop the DFIRM, such as hydrologic and hydraulic models, Flood Profiles, data tables, Digital Elevation Models, and structure-specific data, such as digital elevation certificates and digital photographs of bridges and culverts.
Discharge
The volume of water that passes a given location within a given period of time. Usually expressed in cubic feet per second (cfs).
E
Effective Date
Date of which the Flood Insurance Study Report and Flood
Insurance Rate Map become the official documents for flood insurance rating and floodplain management purposes.
F
Federal Emergency Management Agency (FEMA)
The Federal Emergency Management Agency - a former independent agency that became part of the Department of Homeland Security in March 2003 - is tasked with responding to, planning for, recovering from and mitigating against disasters. The agency's mission is: to lead America to prepare for, prevent, respond to and recover from disasters with a vision of "A Nation Prepared."
Flood (also Flooding)
A general and temporary condition of partial or complete inundation of normally dry land areas. For flood insurance claim purposes, two or more structures must be inundated before flood damage will be covered.
Flood Boundary and Floodway Map (FBFM)
The floodplain management map issued by FEMA that depicts, based on detailed flood hazard analysis, the boundaries of the 1-percent annual chance and the 0.2% annual chance floodplains and, when appropriate, the regulatory floodway. The FBFM does not show flood insurance risk zones or BFEs.
Flood Data Table (FDT)
The Floodway Data Table is found in the Flood Insurance Study for a community and gives details regarding the floodway at cross sections of studied flooding sources in the community. The information provided includes: cross section, distance, floodway width, section area of floodway, mean velocity in the floodway, floodway surcharge and the base flood water surface elevations for the regulatory floodway, with and without floodway scenarios.
Flood Elevation and Detemination Docket (FEDD)
A file maintained during the Post Preliminary Processing
Phase that included all correspondence between the CTP and the community concerning a flood study including letters, meeting minutes, relevant publications (e.g. newspaper notices), Letters of Final Determination, and a copy of the FIRM and FBFM.
Flood Hazard Boundary Map (FHBM)
The initial insurance map issued by FEMA that identifies, based on approximate analysis, the areas of the 1-percent annual chance flood hazard within a community.
Flood Insurance Rate Map (FIRM)
The insurance and floodplain management map produced by FEMA that identifies, based on detailed or approximate analyses, the areas subject to flooding during a 1-percent-annual-chance (100-year) flood event in a community. Flood insurance risk zones, which are used to compute actuarial flood insurance rates, also are shown. In areas studied by detailed analyses, the FIRM shows BFEs to reflect the elevations of the 1-percent-annual-chance flood. For many communities, when detailed analyses are preformed, the FIRM also may show areas inundated by 0.2-percent-annual-chance (500-year) flood and regulatory floodway areas.
Flood Insurance Study (FIS)
The examination, evaluation, and determination of flood hazards performed for a community. This report contains the information found during the study of the community's flooding sources including study methodology, source data, discharges, water surface elevations, flood profiles, and references.
Flood Insurance Study (FIS) Report
A comprehensive document describing a FIS that typically includes a description of the hydrologic and hydraulic analyses, profiles, and tables. This information is used by local and regional planners to further promote sound land use and floodplain development.
Flood Profile
A cross-sectional drawing showing the contiguous cross sections along a stream, with ground elevations and potential flood elevations plotted.
Floodplain Management
The operation of a program of corrective and preventative measures for mitigating flood damage, including, but not limited to, emergency preparedness plans, flood-control works, and floodplain management regulations.
Floodway
Channel of a stream plus any adjacent floodplain areas that must be kept free of encroachment so that the 100-year flood discharge can be conveyed without increasing the elevation of the 100-year flood by more than a specified amount (1 foot in most states).
Freeboard
An additional amount of height above a flood elevation used as a factor of safety (e.g., 1 foot above the base flood elevation) in determining the level at which a structure’s lowest floor must be elevated or floodproofed to be in accordance with State or community floodplain management regulations.
G
Geographic Information System (GIS)
A GIS is a system of computer hardware, software, and procedures designed to support the capture, management, manipulation, analysis, modeling, and display of spatially referenced data for solving complex planning and management problems.
Grandfathering
An exemption based on circumstances previously existing. Under the National Flood Insurance Program, buildings located in Emergency Program communities and Pre-Flood Insurance Rate Map (Pre-FIRM) buildings in the Regular Program are eligible for subsidized flood insurance rates. Post-Flood Insurance Rate Map (Post-FIRM) buildings in the Regular Program built in compliance with the floodplain management regulations in effect at the start of construction will continue to have favorable rate treatment even though higher Base (1% annual chance) Flood Elevations or more restrictive risk zone designations result from Flood Insurance Rate Map revisions.
H
HEC-RAS
A hydraulic model designed to perform one-dimensional hydraulic calculations for a full network of natural and constructed channels.
L
Letter of Final Determination (LFD)
The letter in which FEMA announces its final determination regarding the flood hazard information presented on a new or revised FIRM, FIS, and FBFM for a particular community. In the LFD, FEMA begins the compliance period and establishes the effective date for the new or revised FIRM.
Letter of Map Amendment (LOMA)
An official determination by FEMA that a property has been inadvertently included in a Special Flood Hazard Area (SFHA) as shown on an effective FIRM and is not subject to inundation by the 1-percent-annual-chance flood. Generally, the property is located on natural high ground at or above the BFE or on fill placed prior to the effective date of the first FIRM map designating the property as within an SFHA.
Letter of Map Change (LOMC)
A term used to inclusively define a FEMA letter related to a Flood Insurance Rate Map or Flood Hazard Boundary Map using one or more of the following processes: Letter of Map Amendment (LOMA), Letter of Map Revision (LOMR), Letter of Map Revision based on Fill (LOMR-F) as well as Conditional Letter of Map Revision (CLOMR) and Conditional Letter of Map Revision based on Fill (CLOMR-F).
Letter of Map Revision (LOMR)
A letter issued by FEMA to revise the FIRM and/or FIS report for a community to change BFEs, floodplain and floodway boundary delineations, and coastal hazard areas.
Light Detection and Ranging (LIDAR)
LIDAR refers to an instrument that measures distance to a reflecting object by emitting timed pulses of laser light and measuring the time between emission and reception of reflected pulses. The measured time interval is converted to distance. Airborne LIDAR systems incorporate laser scanners that emit up to 50,000 pulses per second and track the origin and orientation of each pulse through the use of airborne GPS and inertial measurement units so that 3-D coordinates of thousands of points on the ground can be accurately mapped each second of flight. To obtain bare-earth elevations, the LIDAR data are postprocessed to remove elevations on rooftops and dense vegetation not penetrated by the laser light.
Limited Detail Study
The method of Special Flood Hazard Area (SFHA) identification that can be used if a Triangular Irregular Network (TIN) of Light Radar Detection and Ranging (LIDAR) data (or other digital elevation data) with break lines is available. Cross Sections and road data are obtained from these data. Openings of structures and Manning's "n" values may be estimated with limited field inspections. No new field survey is taken. A GIS-based tool may be used to create cross section and structure data for the HEC-RAS program to determine the 1-percent-annual-chance water-surface-elevations. Because the 1-percent-annual-chance water-surface elevations are determined using approximate hydrologic and hydraulic methods with topographic and structural data, BFEs will not be shown on the FIRM, but will be provided to the community and may be used as 'best available data' for floodplain management regulatory purposes.
M
Map Repository
The location where a community's flood maps are kept; usually the local zoning and planning office.
N
National Flood Insurance Program (NFIP)
Federal insurance program under which flood-prone areas are identified and flood insurance is made available to residents of participating communities that agree to adopt and enforce floodplain management ordinances to reduce future flood damage.
O
Orthophotograph
Aerial photographs that have been rectified to produce an accurate image of the Earth by removing tilt and relief displacements that occurred when the photo was taken. An orthophotograph has the same scale throughout and can be used as a base map for the DFIRM.
P
Preliminary DFIRM and FIS
A preliminary Flood Insurance Study Report and Flood Insurance Rate Map are issued to a community for review before finalization. Notice of where the public can review the
preliminary Flood Insurance Study Report and Flood insurance Rate Map is published in a local newspaper.
R
Redelineation
This method of Special Flood Hazard Area (SFHA) identification can only be used for previously studied streams. Using this method, the SFHA boundary is redefined using the effective water surface elevations superimposed on updated topography. No changes are made to the currently effective model. This case involves situations for which new topographic data exists for a study reach or entire county. The new topographic data is more recent and of higher quality than the topographic data originally used in the effective study. When the original hydraulic model is not available digitally but the model is correct, the effective FEMA profile forms the basis of the redelineation. The appropriate vertical datum conversion is applied, and the revised flood boundaries are mapped on the new topographic source. In this case, the BFEs will be republished on the DFIRM. The deliverable will be digital flood boundaries that match best available topographic data, recreated flood profiles, and floodway data tables meeting FEMA's Guidelines and Specifications for Flood Hazard Mapping Partners.
Scoping
Determining what areas are floodprone and need to have flood hazard data developed, what methods will be used to generate these data, and how the data will be presented on a Flood Insurance Rate Map. A comprehensive scoping phase may entail:
• Researching and inventorying available elevation, flood hazard, and digital base map data that may be useful for preparing updated digital Flood Insurance Rate Map panels;
• Assessing existing flood hazard data (e.g., flood elevation profiles, floodplain boundaries, floodways, coastal hazard zones) on effective Flood Insurance Rate Maps for accuracy;
• Outreach to, and input from, counties and communities regarding their needs for updated Flood Insurance Rate Maps;
• Identifying data that need to be developed or acquired, such as digital base maps, digital elevation models, or field surveys of stream channels, and hydraulic structures;
• Determining the proposed scales and paneling scheme for digital Flood Insurance Rate Map production; and
• Developing a schedule for completion of updated flood hazard data and digital Flood Insurance Rate Map production.
Special Flood Hazard Area (SFHA)
The area delineated on a National Flood Insurance Program map as being subject to inundation by the base flood. SFHAs are determined using statistical analyses of records of riverflow, storm tides, and rainfall; information obtained through consultation with a community; floodplain topographic surveys; and hydrologic and hydraulic analyses.