A
Accessory Structure	A structure that is on the same parcel of property as the principal structure to be insured and the use of which is incidental to the use of the principal structure.
Actuarial Rates	Those rates established by the Administrator pursuant to individual community studies and investigations which are undertaken to provide flood insurance in accordance with Section 1307 of the National Flood Disaster Protection Act of 1973 and the accepted actuarial principles. These also include provisions for operating costs and allowances.
Administrator	Federal Insurance Administrator
Agency	Federal Emergency Management Agency (FEMA)
Agricultural Commodities	Agricultural products and livestock.
Agricultural Structure	Any structure used exclusively in connection with the production, harvesting, storage, drying, or raising of agricultural commodities.
Alluvial Fan Flooding	An area of sedimentary deposit located a topographic break such as the base of a mountain front, escarpment, or valley side, that is composed of streamflow and/or debris flow sediments and which has the shape of a fan, either fully or partially extended.
Appeal	A request for review of the Floodplain Administrators interpretation of any provision of this ordinanace or a request for a variance.
Approximate Study	Approximate studies are produced for areas with little existing or planned development. Rather than conducting a detailed riverine study in these areas, it is more cost effective to use existing information including soil data maps, high water profiles, aerial photographs of previous floods, and topographic maps to determine an approximate floodplain boundary.
Appurtenant Structure	A structure that is on the same parcel of property as the principal structure to be insured and the use of which is incidental to the use of the principal structure.
Area of Special Flood Hazard	The land in the floodplain within a community subject to a one percent or greater chance of flooding in any given year.
B
Base Flood	The flood having a one percent chance of being equaled or exceeded in any given year.
Base Flood Elevation	The water surface elevation of the 1% annual chance flood measured in feet.
Basement	Any area of the structure having its floor subgrade (below ground level) on all sides.
Benchmarks	Monuments on the ground that show the elevation of the spot above sea level.
Building	For floodplain management purposes, a walled and roofed building, including a gas or liquid storage tank, that is principally above ground, as well as a manufactured home. "Building" for insurance purposes, means a walled and roofed building, other than a gas or liquid storage tank, that is principally above ground and affixed to a permanent site, as well as a manufactured home on a permanent foundation. For the latter purpose, the term includes a building while in the course of construction, alteration or repair, but does not include building materials or supplies intended for use in such construction, alteration or repair, unless such materials or supplies are within an enclosed building on the premises.
C
Channel	Channels are topographically defined features that carry water through and out of a drainage basin. Smaller channels called tributaries carry the water to the larger channels, and to the lowest body of water in the drainage basin known as the main channel.
Chief Elected Official	The official of the community who is charged with the authority to implement and administer laws, ordinances, and regulations for that community.
Chief Executive Officer	The official of the community who is charged with the authority to implement and administer laws, ordinances, and regulations for that community.
CLOMA	Conditional Letter of Map Amendment filed with FEMA.
CLOMR	Conditional Letter of Map Revision. A statement from FEMA that if a project is constructed as planned, a Letter of Map Revision can be issued later.
Community	Any State or area or political subdivision thereof, which has authority to adopt and enforce floodplain management regulations for the areas within its jurisdiction.
Community Coordination	Meetings held during the Scoping and Post Preliminary Phases of the Map Modernization Program to inform Community officials about the map changes, the program and to seek input for improvements.
Community Rating System (CRS)	The NFIP Community Rating System is a voluntary incentive program that recognizes and encourages community floodplain management activities that exceed the minimum NFIP requirements.
Condensation	Cooler temperatures in the atmosphere cause condensation of the water vapor into clouds.
Contour	A line of equal elevation on a topographic map.
Cooperating Technical Partner (CTP)	The Cooperating Technical Partners (CTP) Program is an innovative approach to creating partnerships between FEMA and participating NFIP communities, regional agencies, and State agencies that have the interest and capability to become more active participants in the FEMA Flood Hazard Mapping Program.
Cross Section	A cross section is an illustration of the shape and elevation of a stream channel and floodplain shown at a right angle to the flow of the stream. Cross sections are surveyed at representative points along a stream channel, and at locations where structures such as bridges and culverts or areas of rough ground may affect the flow of water.
D
Datum	A common vertical elevation reference point, usually in relation to sea level.
DBMS	Database Management System
Detailed Study	Flood hazard mapping studies that are done using hydrologic and hydraulic methods that produce base flood elevation, floodways and other pertinent flood data.
Development	Any man-made change to improved or unimproved real estate, including but not limited to buildings or other structures, levees, levee systems, mining, dredging, filling, grading, paving, excavation or drilling operations, or storage of equipment or materials.
DFIRM	Digital Flood Insurance Rate Map. This is the legal map supported by digital data used by FEMA to determine the hazard risk for flooding for an area.
Dike	A dike is an embankment to confine or control water, and/or soil.
Discharge	The amount of water that passes a point in a given period of time. Rate of discharge is usually measured in cubic feet per second.
Drainage Basin	A drainage basin, also known as a watershed, is an area of land that drains into a body of water, such as a lake or stream. All the precipitation and runoff is collected by channels in the drainage basin.
E
Elevated Building	For insurance purposes, a non-basement building which has its lowest elevated floor raised above ground level by foundation walls, shear walls, posts, piers, pilings, or columns.
Eligible Community	A community for which the Administrator has authorized the sale of flood insurance under the National Flood Insurance Program (NFIP).
Encroachment review	An analysis to determine if a project will increase flood heights or cause increased flooding downstream.
ESRI	Environmental Systems Research Institute
Evaporation	Water from the oceans becomes water vapor through the process of evaporation
Existing Construction	For the purposes of determining rates, structures for which the "start of construction" commenced before the effective date of the FIRM or before January 1, 1975, for FIRMS effective before that date. "Existing construction" may also be referred to as "existing structures".
Existing 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 (including, at a minimum, the installation of utilities, the construction of streets, and either final site grading or the pouring of concrete pads) is completed before the effective date of the floodplain management regulations adopted by a community.
Expansion to an Existing Manufactured Home Park	The preparation of addiitional 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).
F
Fair Market Value	An estimate of what is fair, economic, just and equitable value under normal local market conditions.
FBFM	Flood Boundary Floodway Map. An official map of a community, on which FEMA has delineated the regulatory floodway. Recent Flood Insurance Studies show the floodway on the FIRM and do not include an FBFM.
FEMA	Federal Emergency Management Agency. Most of the National Flood Insurance Program field work and community coordination are done by the 10 FEMA Regional Offices.
FHBM	Flood Hazard Boundary Map. An official map of a community published by FEMA that delineates the approximate boundary of the floodplain. An FHBM is generally the initial map provided the community and is eventually superseded by a FIRM.
FIA	Federal Insurance Administration. FIA was the part of the Federal Emergency Management Agency that administered the National Flood Insurance Program. This is now the responsibility of FEMA's Mitigation Division.
FIRM Panel	Flood Insurance Rate Map. An official map of a community, on which FEMA has delineated both the Special Flood Hazard Areas and the risk premium zones applicable to the community.
FIRM Panel Locator Diagram	Graphic showing where the FIRM is located in reference to the County and other FIRMs within that county.
Flash Floods	A particular type of overbank flooding that most often occurs in areas with a steep terrain. They are characterized by rapidly moving and quick-rising waters. They may be caused by intense rainfall, ice jam, or collapse of a dam or other man-made structure.
Flood	A flood is an overflow of a body of water caused by excessive rainfall or other input of water. Floods occur naturally as part of the hydrologic or water cycle.
Flood	A general and temporary condition of partial or complete innundation of normally dry land areas from (1) the over flow of inland and/or (2) the unusual and rapid accumulation or runoff of surface waters from any source.
Flood Boundary and Floodway Map (FBFM)	An official map of a community on which the Administrator has delineated both special flood hazard areas and the designated regulatory floodway.
Flood Control	The Flood Control Act of 1936 established federal interest in controlling floods on the nation's navigable waters and their tributaries. Under the Act, $310 million was authorized for carrying out flood control projects, with the U.S. Army Corps of Engineers receiving major responsibilities for mainstem and downstream projects. The Soil Conservation Service was later assigned responsibility for flood protection on upstream watersheds. In addition, the Bureau of Reclamation and the Tennessee Valley Authority are involved in the construction of flood damage reduction structures. The Tennessee Valley Authority has played a role in flood control since its creation in 1933; two of its statutory purposes are to improve navigation in the Tennessee River and to control destructive flood waters in the Tennessee River and Mississippi River Basin.
Flood Elevation Determination	A determination by the Administrator of the water surface elevations of the base flood, that is, the flood level that has a one percent or greater chance of occurence in any given year.
Flood Elevation Study	An examination, evaluation and determination of flood hazards.
Flood Fringe	The area outside the floodway encroachment lines, but still subject to inundation by the regulatory flood.
Flood Hazard Boundary Map (FHBM)	An official map of a community, issued by the Administrator, where the boundaries of the flood areas having special flood hazards have been designated as (unnumbered or numbered) A zones.
Flood Hazard Boundary Map (FHBM)	Flood Hazard Map based upon approximate data to identify, in general, the special flood hazard areas within a community.
Flood Insurance Rate Map (FIRM)	An official map of a community, on which the Administrator has delineated both the special flood hazard areas and the risk premium zones applicable to the community.
Flood Insurance Study (FIS)	An examination, evaluation and determination of flood hazards and, if appropriate, corresponding water surface elevations.
Flood Risk Zones	Flood hazard areas identified on the FIRM are identified as a Special Flood Hazard Area (SFHA). SFHA are defined as the area that will be inundated by the flood event having a 1%-annual-chance of being equaled or exceeded in any given year. SFHAs are labeled as Zone A, Zone AO, Zone AH, Zones A1-A30, Zone AE, Zone A99, Zone AR, Zone AR/AE, Zone AR/AO, Zone AR/A1-A30, Zone AR/A, Zone V, Zone VE, and Zones V1-V30.
Flood-prone Area	Any land area susceptible to be inundated by water from any source (see "flooding").
Flooding	A general and temporary condition of partial or complete innundation of normally dry land areas from (1) the over flow of inland and/or (2) the unusual and rapid accumulation or runoff of surface waters from any source.
Floodplain	Any land area susceptible to being inundated by water from any source ( see "flooding").
Floodplain Management	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 works, and floodplain management regulations.
Floodplain Management Regulations	Zoning ordinances, subdivision regulations, building codes, health regulations, special purpose ordinances (such as floodplain and grading ordinances) and other applications of police power. Ther term describes such state or local regulations, in any combination thereof, that provide standards for the purpose of flood damage prevention.
Floodproofing	Any combinations of structural and nonstructural additions, changes, or adjustments to structures that reduce or eliminate flood damage to real estate or improved real property, water and sanitary facilities, or structures and their contents.
Floodwalls	A floodwall is a wall, usually built of reinforced concrete, to confine stream flow to prevent flooding.
Floodway	The channel of a river or other watercourse and the adjacent land areas that must be reserved in order to discharge the base flood without cumulatively increasing the water surface elevation more than one foot.
Floodway Encroachment Lines	The lines marking the limits of floodways on Federal, State and local floodplain maps.
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 bridge openings and the hydrological effect of urbanization of the watershed.
Functionally Dependent Use	A use that cannot perform its intended purpose unless it is located or carried out in close proximity to water. This term includes only docking facilities and facilities that are necessary for the loading and unloading of cargo or passengers, but does not include long-term storage or related manufacturing facilities.
G
GIS	Geographic Information Systems
GUI	Graphical User Interface
H
Hazard Mitigation Strategies	Hazard mitigation strategies are defined as “all actions that can be taken to reduce property damage and the threat to life and public health from flooding.”
High Flow Diversions	High flow diversions intercept flood waters upstream of a damage-prone or constricted area and convey them around it through an artificial channel or a designated flow-way. Diversions may either completely reroute a stream or collect and transport only excessive or potentially damaging flows.
Highest Adjacent Grade	The highest natural elevation of the ground surface prior to construction next to the proposed walls of a structure.
Historic Structure	Any structure that is (a) listed individually in the National Register of Historic Places (a listing maintained by the Department of Interior) or 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; (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.
Hurricane	A hurricane is a storm, originating in the tropics, that circulates around a center of low pressure. Hurricanes carry high winds, heavy rain, tornadoes, and they cause storm surges. A hurricane is a type of tropical cyclone. Tropical cyclones are categorized based on their wind speeds and hurricanes have the highest winds speeds. Tropical cyclones with lower wind speeds are called tropical depressions and tropical storms
Hydraulic Analysis	Hydraulic analyses for flood studies focus on determining the water surface elevations in a stream channel and on the floodplain during a flood event. Hydraulic studies are produced for each cross section, and serve as the primary source of data for developing floodplain maps.
Hydrodynamic Forces	Hydrodynamic force is the force of moving water.
Hydrologic Analysis	In a riverine flood study, hydrologic analyses are conducted to estimate the volume and peak discharge of water that will reach and flow in a stream during a flood event. Engineers use computer models to estimate the magnitude of these parameters that will result in a flood event.
Hydrologic Cycle	The hydrologic cycle endlessly circulates water through the environment through the processes of evaporation, condensation, precipitation, runoff, and infiltration.
Hydrostatic Forces	Standing water as well as moving water can cause damage to a structure. Hydrostatic force is the weight of the standing water, which exerts equal downward and lateral (sideways) pressure on a structure. Most walls cannot withstand a lot of lateral pressure. Three feet of standing water is enough to collapse the walls of a typical frame house. Basement walls and floors are also very susceptible to hydrostatic pressure damage. The combined downward pressures from standing water and uplift from the saturated earth beneath the basement can cause the basement floor and walls to collapse and break.
I
Infiltration	Basement walls and floors are also very susceptible to hydrostatic pressure damage. The combined downward pressures from standing water and uplift from the saturated earth beneath the basement can cause the basement floor and walls to collapse and break.
J
K
L
Levee	A levee is a dike or embankment, generally constructed close to the banks of a stream, lake or other body of water, intended to protect the landslide from inundation or to confine the streamflow to its regular channel.
Levee-protected Areas	Another urban drainage problem occurs in areas protected by levees. Since the protected areas are in a natural floodplain and do not have an outlet to drain, they must be pumped dry. Sometimes the capacity of the pumps is exceeded and shallow floodwaters remain in the area protect by the levee until the pumps can catch up.
Leverage	The more resources a local community or the State can contribute towards a DFIRM project via funding or in-kind support, the further the FEMA dollars will go in producing new, revised, or updated mapping to address outstanding mapping needs. Identifying Leverage is an Important Role of the CTP. Possible leverage sources include Local base map data, Local funding of improved topographic data, Surveying and field reconnaissance work, Local appropriations of funds, Securing state grants, and GIS services.
LIDAR	Airborne Light Detection and Ranging (LIDAR) is an increasingly popular way to gather data to create digital elevation models and digital terrain maps. LIDAR systems are airborne laser systems flown aboard rotary or fixed-wing aircraft and are used to acquire x, y and z coordinates of manmade and naturally occurring terrain and terrain features.
Limited Detailed Study	Like a detailed study, a Limited Detail Study will also provide the 1-percent and 0.2 percent annual-chance floodplain, but this will be typically be based on fewer surveyed cross sections than the detailed study. The limited detail study will still map and publish a BFE, but will not typically have a regulatory floodway.
LOMA	A LOMA is issued for amendments to the flood map that only affects an isolated area or building.
LOMC	A LOMC is issued for only a portion of a parcel or may state that only a specifically described portion is removed from the SFHA.
LOMR	A LOMR is issued for restudies, limited map maintenance projects, and revisions.
LOMR-F	A LOMR-F refers to a LOMR based on new fill in the floodplain.
Lowest Floor	The lowest floor of the lowest enclosed areas, including basement. An unfinished or flood-resistant enclosure, usable solely for parking or vehicles, building access, or storage, in an area other than a basement area, is not considered a buildings lowest floor, provided that such enclosure is not built so as to render the structure in violation of the acceptable floodproofing design requirements of the ordinance.
M
Manufactured Home	A structure, transportable in one or more sections, that is built on a permanent chassis and is designed for use with or without permanent foundation when attached to the required utilities. The term "manufactured home" does not include a "recreational vehicle".
Manufactured Home Park or Subdivision	A parcel (or contiguous parcels) of land divided into two or more manufactured home lots for rent or sale.
Map	The Flood Hazard Boundary Map (FHBM), Flood Insurance Rate Map (FIRM), or the Flood Boundary and Floodway Map (FBFM) for a community issued by the Federal Emergency Management Agency (FEMA).
Map Effective Date	The date in the title block shows the map’s most recent revision. As changes occur within a community that result in changes to flood elevations or floodplain delineations, FEMA republishes only the Map Index and the changed map panels. Any revised panels are given a new map revision date and a new suffix letter. Once the panels are issued to the community, the date on the panel is referred to as the effective date. Some communities have map panels with different effective dates. The Map Index lists the current effective date for the most recently revised panel of a FIRM or of the FIRM itself, if all panels were revised. With each revision comes a new panel suffix.
Map Index	The Map Index shows the community’s boundaries, highlighting prominent features such as major highways, railroads, and streams. In many cases, a community is too large, geographically, to be shown on one map and is divided into map panels. The map index shows how the community is displayed on the various map panels.
Map Legend	The legend is the map key that identifies the symbols on the Flood Map and provides information to assist users, including explanations of the various flood risk zone designations. The legend includes the Map Scale, North Arrow, Types of Flood Risk Zones, and Effective Dates, as well as Types of Horizontal Reference Grids, and Types of Bench Marks.
Map Maintenance	Map Maintenance deals with the processes and procedures FEMA plans to follow in order to keep the DFIRMs up-to-date in the future. Benefits of the DFIRMs are that maps will be easier to maintain, update and improve upon in the future.
Map North Direction	An arrow pointing north is shown on all maps, including the map index. For FIRMs, the north direction arrow is located near the map scale. The north direction on the maps may be “turned” to maximize the mapped area that can be shown on a panel and to minimize the number of panels. To ensure correct orientation and accurate use of the FIRM, it is very important to pay attention to the direction of the north arrow on the panel.
Map Revision	A map revision is issued for other cases, including Scientifically based challenges to the flood elevations; To incorporate new data effective after the construction of a flood control project; To reflect fill placed in the floodplain after the flood study currently in effect was completed; To change the floodplain or floodway boundaries; or, To include new flood data.
Map Scales	The map scale is provided on each panel. Different scales may be used for a single community with more than one panel, depending on the size of the mapped area and the base map that is used.
Mapping Activity Statement (MAS)	A key component of the Cooperative Agreement package. It defines the activities that will be accomplished, the entities responsible for accomplishing those activities, how the activities will be funded, and the nature of the working relationship between FEMA and its Partners.
Mapping Information Platform (MIP)	The MIP is an important part of the Map Modernization Process and has many different functions. Study Contractors upload deliverables to the MIP as each step in the MAS is completed. This part of the MIP not available for public use, and is accessible to project mapping partners only via login/password. The status of DFIRM projects can be tracked as they are being developed so that the CTP, FEMA, the mapping contractor can be aware of work tasks, responsibilities and ensuing deadlines. Access to flood hazard mapping and data is provided via the web both as preliminary data becomes available and after map adoption as required to determine insurance rates.
Mapping Needs Assessment	This is a report designed to aid in prioritizing county mapping projects and is made up of areas that need updated study and mapping because the current information is inaccurate or not detailed enough or that require new mapping because flood hazards have not been identified to date. They also include changes and updates needed to reflect changes in jurisdiction, roads, etc.
Mapping Needs Update Support System (MNUSS)	A computerized database system used by FEMA and its mapping partners to compile information and manage the mapping needs assessment process.
Market Value	An estimate of what is fair, economic, just and equitable value under normal local market conditions.
Mean Sea Level	For purposes of the National Flood Insurance Program (NFIP), the National Geodetic Vertical Datum (NGVD) of 1929 or other datum, to which base flood elevations shown on a communitys Flood Insurance Rate Map (FIRM) are referenced.
Mid Course Adjustment	FEMA performed a mid-program evaluation. As a result, FEMA is implementing changes to emphasize on the quality of the modernized maps over production of a large number of maps.
Mudflow	Mudflow is a condition where there is a river, flow, or inundation of liquid mud down a hillside usually as a result of a dual condition of loss of brush cover, and the subsequent accumulation of water on the ground preceded by a period of unusually heavy or sustained rain.
Multi-Year Flood Hazard Identification Plan (MHIP)	The Multi-Year Flood Hazard Identification Plan (MHIP) details FEMA's ongoing 5-year plan for providing updated digital flood hazard data and maps for areas with flood risk. This nationwide plan reflects input and information provided by each state’s Map Modernization Business Case Plan as well as each FEMA Regional office’s plan. The MHIP provides detailed information about projected flood map production sequencing and projected funding allocations at the county level. Actual funding levels for county flood map updates are determined as FEMA Regional Offices examine their annual funding allocations and as countywide flood mapping projects are scoped and projects are further defined.
N
National Flood Insurance Program (NFIP)	The NFIP is a cooperative program between the Federal government and the communities that participate in the program. Federal, state, and local governments and private insurance companies have certain roles and responsibilities. It has three inter-related, mutually-supportive components of the NFIP: Mapping – establishes where flood risks are; Insurance – insures those at risk of flooding; and Regulations – protects from mapped flood hazards and prevents flooding from worsening.
New Construction	For the purposes of determining insurance rates, structures for which the "start of construction" commenced on or after the effective date of an initial FIRM or after December 31, 1974, whichever is later, and includes any subsequent improvements to such structures. For floodplain management purposes, "new construction" means structures for which the "start of construction" commenced on or after the effective date of the floodplain management regulations adopted by a community and includes any subsequent improvements made to such structures.
New Manufactured Home Park or Subdivision	A manufactured home park or subdivision for which the construction of facilities for servicing the lot 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 completed on or after the effective date of floodplain management regulations adopted by the community.
NIFP	The National Flood Insurance Program (NFIP)
Nor’easters	A nor’easter is a large non-tropical, or “extratropical” storm whose winds come from the northeast and that forms around an area of low pressure. Nor’easters affect the northeastern United States and Canadian Atlantic coastal regions. Like tropical cyclones, they carry heavy precipitation (rain and/or snow) that can cause flooding.
Note to Users	The reference area on a map that provides detailed information that the user should be made aware.
O
Overbank Flooding	Overbank flooding is a general term for flooding that occurs when the amount of water in a channel exceeds its capacity and flows out onto the floodplain. The characteristics of an overbank flood vary with the terrain and size of the drainage basin. In a flat area, people may know hours or even days ahead of time that flooding will occur.
P
Participating Community	A community for which the Administrator has authorized the sale of flood insurance under the National Flood Insurance Program (NFIP).
Person	Any individual or group of individuals, corporation, partnership, association, or any other entity, including Federal, State, and local governments and agencies.
Photogammetric Mapping	Involves obtaining accurate measurements of the land (e.g., topography) based on photographs taken from the air.
Political Boundary Lines	State, county and city limit boundary lines.
Ponding	Ponding occurs when runoff collects in depressions and cannot drain out. Runoff in temporary ponds remains until it infiltrates into the soil, evaporates, or is pumped out.
Post Preliminary Processing	Post Preliminary Processing consists of finalizing the DFIRM and FIS report after the Preliminary copies of the DFIRM and FIS report have been issued to community officials and the public for review and comment. Upon receipt of the preliminary FIS Report and DFIRM, communities are given an initial 30-day community comment period. Generally FEMA will require an actual Community Coordination Meeting to be held as part of this process. It provides due process to the citizens of the county and allows for an appeals and protest period. It further provides time for the community to adopt the new floodplains in their ordinances. The entire process may take up to 1 year to complete.
Precipitation	Air currents move the clouds around the globe. The cloud particles collide, grow, and become precipitation. Some precipitation falls as snow and can accumulate as ice caps and glaciers, which can store frozen water for thousands of years
Preliminary DFIRM	Post Preliminary Processing consists of finalizing the DFIRM and FIS report after the Preliminary copies of the DFIRM and FIS report have been issued to community officials and the public for review and comment. Upon receipt of the preliminary FIS Report and DFIRM, communities are given an initial 30-day community comment period. Generally FEMA will require an actual Community Coordination Meeting to be held as part of this process.
Principally Above Ground	At least 51% of the actual cash value of the structure, less land value, is above ground.
Profile	A flood profile is created by plotting the flood water elevations that were determined at each cross section during the hydraulic study on a graph, and connecting the points. The x-axis of a flood profile shows the distance along a stream (known as stationing), and progresses upstream from left to right. The y-axis shows the water surface elevation. A flood profile can be used to determine the flood elevation at any point along a stream.
Q
Quality Assurance/Quality Control (QA/QC)	Quality Control steps are built into the DFIRM production process. This ensures that the modeling, analysis, data and deliverables required in many of the key data collection, analysis and mapping steps are correct and meet all of FEMA’s guidelines and specifications.
R
Recreational Vehicle	A vehicle which is (a) built on a single chassis; (b) 400 square feet or less when measured at the largest horizontal projections; (c) designed to be self-propelled or permamently towable by a light-duty truck and (d) designed not for use as a permanent dwelling but as temporary living quarters for recreational, camping, travel, or seasonal use.
Redelineation	Redelineation occurs if no new modeling is completed, but better topographic data is available for a mapped area (better than what was available when the original mapping was completed). In these areas, the existing data can be redelineated onto the better topographic data to produce more accurate floodplain boundaries between cross sections.
Regulatory Floodway	The channel of a river or other watercourse and the adjacent land areas that must be reserved in order to discharge the base flood without cumulatively increasing the water surface elevation more than one foot.
Remedy A Violation	To bring the structure or other development into compliance with Federal, State, or local floodplain management regulations; or, if this is not possible, to reduce the impacts of its noncompliance.
Repetitive Loss	Flood-related damages sustained by a structure on two separate occasions during a 10-year period for which the cost of repairs at the time of each such flood event, equals or exceeds twenty-five percent of the market value of the structure before the damage occurred.
Risk Premium Rates	Those rates established by the Administrator pursuant to individual community studies and investigations which are undertaken to provide flood insurance in accordance with Section 1307 of the National Flood Disaster Protection Act of 1973 and the accepted actuarial principles. "Risk premium rates" include provisions for operating costs and allowances.
Runoff	Most precipitation falls back into the oceans or onto land, where due to gravity, the precipitation flows over the ground as surface runoff. A portion of runoff enters rivers in valleys in the landscape, with streamflow moving water towards the oceans. Runoff and ground-water seepage accumulate and are stored as freshwater in lakes
S
Scoping	The assessment of community mapping needs (flood data update, map maintenance, and/or digital conversion) completed during the Mapping Needs Assessment Process. During Project Scoping, all aspects of the project are considered and planned for, and a tailored scope of work for FEMA’s mapping partners is developed. Project Scoping ends when activities for Map Production (which includes engineering analysis, floodplain mapping, DFIRM production, and legal due process) have been assigned to the Project Team members.
Sediment	Floodwaters carry debris, sediment, oil, farm and lawn chemicals, and, if a waste water treatment plant is upstream, untreated sewage. When floodwaters inundate structures and soak into materials, they leave sediment and contaminants behind. Even when a flooded house dries out, it is far from clean. Some items such as carpet and mattresses may not be worth drying out and cleaning.
SEMA	State Emergency Management Agency
Shaded Zone X	Areas of 0.2% annual chance flood; areas of 1% annual chance flood with average depths of less than 1 foot or with drainage areas less than 1 square mile; and areas protected by levees from 1% annual chance flood.
Shallow Flooding	Shallow flooding is non-riverine, non-coastal flooding. It occurs where there are few or inadequate channels so that water cannot drain away easily. Shallow flooding problems can be categorized as sheet flow, ponding or urban drainage problems.
Sheet Flow	Sheet flow is floodwater that spreads out over a large area that does not have defined channels at a nearly uniform depth
Soaking	Structures and other property are often damaged during a flood by soaking in water. Soaking may cause materials to change composition or shape. Wood warps, dry wall swells and cracks, and electrical appliances are often damaged beyond repair when soaked with water.
Special Flood Hazard Area (SFHA)	The land in the floodplain within a community subject to a one percent or greater chance of flooding in any given year.
Special Hazard Area	An area having special flood hazards and shown on an FHBM, FIRM or FBFM as zones (unnumbered or numbered) A and AE.
Start of Construction	Includes substantial-improvements, and means the date the building permit was issued, provided the actual start of construction, repair, reconstruction, rehabilitation, addition placement, or other improvements were within 180 days of the permit date. The actual start means either the first placement of permanent construction of a structure on a site, such as the pouring of slabs or footings, the installation of piles, the construction of columns, any work beyond the stage of excavation, or the replacement of a manufactured home on a foundation. Permanent construction does not include land preparation, such as clearing, grading and filling, the installation of streets and/or walkways, excavation for a basement, footings, piers, foundations, the erections of temporary forms, nor installation on the property of accessory structures, 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 that alteration affects the external dimensions of the building.
State Coordinating Agency	That agency of the state government, or other office designated by the governor of the state or by state statute at the request of the Administrator to assist in the implementation of the National Flood Insurance Program (NFIP) in that state.
Storm Surge	A storm surge is water that is pushed to shore by persistent high winds and changes in air pressure. In a large water body, a storm surge can raise the water level by several feet, causing severe inland flooding
Stormwater Management	Stormwater management is the removal of water that falls directly onto a property as opposed to flood water that flows onto the property from upstream sources or an ocean surge. Stormwater management involves both modifying the quantity as well as the quality of stormwater during a rain or flood event.
Stream Names	River or creek names.
Structure	For floodplain management purposes, a walled roofed building, including a gas or liquid storage tank, that is principally above ground, as well as a manufactured home. "Structure" for insurance purposes, means a walled and roofed building, other than a gas or liquid storage tank, that is principally above ground and affixed to a permanent site, as well as a manufactured home on a permanent foundation. For the latter purpose, the term includes a building while in the course of construction, alteration or repair, but does not include building material or supplies intended for use in such construction, alteration or repair, unless such materials or supplies are within an enclosed building on the premises.
Substantial Damage	Damage of any origin sustained by a structure whereby the cost of restoring the structure to its before damaged condition would equal or exceed 50% of the market value of the structure before the damage occurred. The term includes Repetitive Loss buildings. For the purposes of this definition, "repair" is considered to occur when the first repair or reconstruction of any wall, ceiling, floor, or other structural part of the building commences. The term does not apply to: (a) Any project for improvement of a building required to comply with existing health, sanitary, or safety code specifications which have been identified by the Code Enforcement Official and which are solely necessary to assure safe living conditions, or (b) Any alteration of a "historic structure" provided that the alteration will not preclude the structures continued designation as a "historic structure", or (c) Any improvement to a building.
Substantial Improvement	Any combination of reconstruction, alteration, or improvement to a building, taking place during the life of the building, in which the cumulative percentage or improvement equals or exceeds fifty percent of the current market value of the building. For the purposes of this definition, an improvement occurs when the first alteration to any wall, ceiling, floor, or other structural part of the building commences, whether or not that alteration affects the external dimensions of the building. This term includes structures, which have incurred "repetitive loss" or "substantial damage", regardless of the actual repair work done. This term does not apply to: (a) Any project for improvement of a building required to comply with existing health, sanitary, or safety code specifications which have been identified by the Code Enforcement Official and which are solely necessary to assure safe living conditions, or (b) Any alteration of a "historic structure" provided that the alteration will not preclude the structures continued designation as a "historic structure", or (c) Any building that has been damaged from any source or is categorized as repetitive loss.
Substantially improved existing manufactured	Where the repair, reconstruction, rehabilitation or improvement of the streets, utilities and pads equals or exceeds 50% of the value of the streets, utilities and pads before the repair, reconstruction or improvement commenced.
Summary of Map Actions (SOMA)	A Summary of Map Actions (SOMA) letter explains how the new DFIRM information will impact any existing Letters of Map Changes (LOMCs) on record at FEMA. This letter must be included with the transmittal letter and draft DFIRM products.
T
Title Block	The reference area on a FIRM panel that provides the title of the map, the map number, status of effectiveness, north arrow, scale, date and location of the map.
Transportation Lines	Roads, highways, interstates and railroad lines.
U
Unshaded Zone X	Areas of 0.2% annual chance flood.
Urban Drainage	Urban drainage systems are made up of ditches, storm sewers, detention ponds, and other facilities that are constructed to collect runoff from developed areas and carry it to a receiving stream, lake, or ocean.
V
Variance	A grant of relief by the community from the terms of a floodplain management regulation. Flood insurance requirements remain in place for any varied use of structure and cannot be varied by the community.
Violation	The failure of a structure or other development to be fully compliant with the communitys floodplain management regulations. A structure or other development without the elevation certificate, other certifications, or other evidence of compliance required by this ordinance is presumed to be in violation until such time as that documentation is provided.
W
Water Surface Elevation	The height, in relation to the National Geodetic Vertical Datum (NGVD) of 1929 (or other datum where specified) of those floods of various magnitudes and frequencies in the floodplain.
X
Y
Z
Zone A	Special Flood Hazard Area (SFHA) with no base flood elevations determined. Also called Approximate Zones.
Zone AE	Special Flood Hazard Area (SFHA) with base flood elevations determined.