FEMA Flood Zone Designations

Transcription

1 Note: SFHA "Special Flood Hazard Area" FEMA Flood Zone Designations Zone VE Zone A Zone AE Zone X Zone X500 UNDES along coasts subject to inundation by the 100-year flood with additional hazards due to velocity (wave action). Base flood elevations derived from detailed hydraulic analyses are shown within these zones. Mandatory flood insurance purchase requirements apply. subject to inundation by the 100-year flood. Because detailed hydraulic analyses have not been performed, no base flood elevation or depths are shown. Mandatory flood insurance purchase requirements apply. 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. These areas have been identified in the community flood insurance study as areas of moderate or minimal hazard from the principal source of flood in the area. However, buildings in these zones could be flooded by severe, concentrated rainfall coupled with inadequate local drainage systems. Local stormwater drainage systems are not normally considered in the community's FIS. The failure of a local drainage system creates areas of high flood risk within these rate zones. Flood insurance is available in participating communities, but is not required by regulation in these zones. The same description as Zone X, however, this area falls between the 100 and 500-year flood zone. Undescribed. No information available. What do the different flood zones mean? The following table gives an explanation for the flood zone designations used by FEMA: Annual Probability of Flooding of 1% or greater A AE or A1-A30 Subject to 100-year flood. Base flood elevation undetermined. Both AE and A1-A30 represent areas subject to 100-year flood with base flood elevation determined.

2 AH AO AOVEL A99 AR V VE or V1-V30 Subject to 100-year shallow flooding (usually areas of ponding) with average depth of 1-3 feet. Base flood elevation determined. Subject to 100-year shallow flooding (usually sheet flow on sloping terrain) with average depth of 1-3 feet. Base flood elevation undetermined. Alluvial fan subject to 100-year shallow flooding (usually sheet flow on sloping terrain) for which average flood depths and velocities have been determined. Average flood depth of 1-3 feet. Subject to 100-year flood, with federal flood protection system (levee/dam) under construction. Base flood elevation undetermined. Previously accredited flood protection system has been decertified and is in the process of being restored to provide a 100-year or greater level of flood protection. Subject to 100-year flood and additional velocity hazard (wave action). Base flood elevation undetermined. Both VE and V1-V30 represent areas subject to 100-year flood and additional velocity hazard (wave action). Base flood elevation determined. In SFHA Areas in a "Special Flood Hazard Area" (or 100-year flood plain). Subject to 1% annual chance flooding. No distinctions have been made between the different flood hazard zones that may be included within the SFHA. Flood Prone Area An area designated as a "Flood Prone Area" on a map prepared by USGS and the Federal Insurance Administration. This area has been delineated based on available information on past floods. This is an area inundated by 1% annual chance flooding for which no base flood elevations have been determined. Annual Probability of Flooding of 0.2% - 1% B or X500 Both B and X500 represent areas between the limits of the 100-year and 500-year flood; or certain areas subject to 100-year flood with average depths less than 1 foot or where the contributing drainage area is less than 1 square mile; or areas protected by levees from the 100-year flood. Annual Probability of Flooding of Less than 0.2% C or X Both C and X represent areas outside the 500-year flood plain with less than 0.2% annual probability of flooding. Annual Probability of Flooding of Less than 1%

3 No SFHA Areas outside a "Special Flood Hazard Area" (or 100-year flood plain). Can include areas inundated by 0.2% annual chance flooding; areas inundated by 1% annual chance flooding with average depths of less than 1 foot or with drainage areas less than 1 square mile; areas protected by levees from 1% annual chance flooding; or areas outside the 1% and 0.2% annual chance floodplains. Undetermined D Unstudied areas. Flood hazards are undetermined. What do the different flood zones mean? The following table gives an explanation for the flood zone designations used by Transamerica : Zone Zone Name Description Error (Missing data) 100 Area in SFHA 100IC A A99 AE 100-year Flood Discharge Contained in Channel Zone A Zone A99 Zone AE Error (Missing data). This is an area inundated by 100-year flooding for which BFEs or velocity may have been determined. No distinctions are made between the different flood hazard zones that may be included within the SFHA. An area where the 100-year flooding is contained within the channel banks and the channel is too narrow to show to scale. An arbitrary channel width of 3 meters is shown., for which no This is an area to be protected from the 100-year flood by a Federal flood protection system under construction., for which

4 AH ANI AO AR B BE BX C CE CX D FW Zone AH Area Not Included Zone O Zone AR Zone B Zone BE Zone BX Zone C Zone CE Zone CX Zone D Floodway (usually an area of ponding), for which BFEs have been determined; flood depths range from 1 to 3 feet. An area that is located within a community or county that is not mapped on any published FIRM. (usually sheet flow on sloping terrain), for which average depths have been determined; flood depths range from 1 to 3 feet. An area inundated by flooding, for which BFEs or average depths have been determined. An area inundated by 500-year flooding; an area inundated by 100-year flooding with average depths of less than 1 foot or with drainage areas less than 1 square mile; or an area protected by levees from 100- year flooding. An area inundated by 500-year flooding; an area inundated by 100-year flooding with average depths of less than 1 foot or with drainage areas less than 1 square mile; or an area protected by levees from 100- year flooding. An area inundated by 500-year flooding; an area inundated by 100-year flooding with average depths of less than 1 foot or with drainage areas less than 1 square mile; or an area protected by levees from 100- year flooding. An area that is determined to be outside the 100- and 500-year floodplains. An area that is determined to be outside the 100- and 500-year floodplains. An area that is determined to be outside the 100- and 500-year floodplains. An area of undetermined but possible flood hazards. An area that includes the channel of a river or other watercourse (Usually adjacent to

5 FWIC IN NM OUT UNDES V VE X X5 Floodway Contained in Channel Area In SFHA Area Not Mapped Area Not Mapped Area of Undesignated Flood Hazard Zone V Zone VE Zone X Zone X (500- year) Zone AE). An area where the floodway is contained within the channel banks and the channel is too narrow to show to scale. An arbitrary channel width of 3 meters is shown. BFEs are not shown in this area, although they may be reflected on the corresponding profile This is an area inundated by 100-year flooding for which BFEs or velocity may have been determined. No distinctions are made between the different flood hazard zones that may be included within the SFHA. An area that is located within a community or county that is not mapped on any published FIRM. An area designated as outside a "Special Flood Hazard Area" (or SFHA) on a FIRM. This is an area inundated by 500- year flooding; an area inundated by 100- year flooding with average depths of less than 1 foot or with drainage areas less than 1 square mile A body of open water, such as a pond, lake ocean, etc., located within a community's jurisdictional limits that have no defined flood hazard. with velocity hazard (wave action); BFEs have been determined. An area that is determined to be outside the 100- and 500-year floodplains. An area inundated by 500-year flooding; an area inundated by 100-year flooding with average depths of less than 1 foot or with drainage areas less than 1 square mile; or an area protected by levees from 100- year flooding. X500 Zone X (500- An area inundated by 500-year flooding;

6 X500IC A1 A2 A3 A4 A5 A6 A7 A8 A9 A10 A11 A12 A13 A14 A15 year) 500-year Flood Discharge Contained in Channel Zone A1 Zone A2 Zone A3 Zone A4 Zone A5 Zone A6 Zone A7 Zone A8 Zone A9 Zone A10 Zone A11 Zone A12 Zone A13 Zone A14 Zone A15 an area inundated by 100-year flooding with average depths of less than 1 foot or with drainage areas less than 1 square mile; or an area protected by levees from 100- year flooding. An area where the 500-year flooding is contained within the channel banks and the channel is too narrow to show to scale. An arbitrary channel width of 3 meters is shown. A16 Zone A16

7 A17 A18 A19 A20 A21 A22 A23 A24 A25 A26 A27 A28 A29 A30 V0 V1 V2 V3 Zone A17 Zone A18 Zone A19 Zone A20 Zone A21 Zone A22 Zone A23 Zone A24 Zone A25 Zone A26 Zone A27 Zone A28 Zone A29 Zone A30 Zone V0 Zone V1 Zone V2 Zone V3

8 V4 V5 V6 V7 V8 V9 V10 V11 V12 V13 V14 V15 V16 V17 Zone V4 Zone V5 Zone V6 Zone V7 Zone V8 Zone V9 Zone V10 Zone V11 Zone V12 Zone V13 Zone V14 Zone V15 Zone V16 Zone V17

9 V18 V19 V20 V21 V22 V23 V24 V25 V26 V27 V28 V29 V30 Z Zone V18 Zone V19 Zone V20 Zone V21 Zone V22 Zone V23 Zone V24 Zone V25 Zone V26 Zone V27 Zone V28 Zone V29 Zone V30 Area of Unknown Flood An area of Data Discrepancy or an Unclaimed Area. Internal TFHC

10 N AR/A Hazard Area Not Mapped Zone AR/A AR/AE Zone AR/AE AR/AE Zone AR/AH designation. An area that is located within a community or county that is not mapped on any published FIRM (Usually a community not participating in NFIP). Internal TFHC designation. An area inundated by flooding, for which BFEs or average depths have not been determined. An area inundated by flooding, for which BFEs or average depths have been determined. An area inundated by flooding, for which BFEs or average depths have been determined.