The National Flood Hazard Layer (NFHL) is a geospatial database that contains current effective flood hazard data. FEMA provides the flood hazard data to support the National Flood Insurance Program. You can use the information to better understand your level of flood risk and type of flooding. The simplest way for you to access the flood hazard data, including the NFHL, is through FEMAs Map Service Center (MSC).If you want to explore the current digital effective flood hazard data in a map, the best tool to use is the NFHL Viewer. From the NFHL Viewer, you may view, download, and print flood maps for your location.The NFHL is made from effective flood maps and Letters of Map Change (LOMC) delivered to communities. NFHL digital data covers over 90 percent of the U.S. population. New and revised data is being added continuously. If you need information for areas not covered by the NFHL data, there may be other FEMA Flood Hazard Products and Services which provide coverage for those areas.A list of the types of data available in the NFHL and information about other ways to access the NFHL may be found in the NFHL GIS Services User Guide.If you need more information about individual tables in the NFHL, the FIRM Database Technical Reference, found at FEMA’s Technical References, includes those details.For step-by-step instructions on how to read a flood map, you may view the How to Read a Flood Insurance Rate Map Tutorial.For more information, please visit the FEMA Flood Map Service Center.

This resource describes a dataset of gridded depth at horizontal resolution of 3 meters, published November 15, 2017, downloaded from FEMA [1] and hosted in this archive at the University of Texas Advanced Computing Center (TACC) [2].. The raster dataset is contained within an Esri ArcGIS geodatabase. This product utilized Triangulated Irregular Network (TIN) interpolation, four quality assurance measures (identifying dips, spikes, duplication, and inaccurate/unrealistic measurements). High Water Marks were obtained from the Harris County Flood Control District (HCFCD), US Geological Survey (USGS), and other inspection data. Elevation data comprised a mosaic of 3 meter resampled elevations from 1M & 3M LiDAR, and IFSAR data. One section of the IfSAR data was found to be erroneous, and replaced with a blended 10 meter section. [This description was in correspondence January 22, 2018, from Mark English, GeoSpatial Risk Analyst, FEMA Region VIII, Mitigation Division.]

A preliminary version of these depths dated September 10, 2017 can be viewed in a FEMA web map [3]. This web map shows a forecasted depth grid, based on National Weather Service (NWS) Advanced Hydrologic Prediction Service (AHPS) forecasted water levels.

See FEMA's Natural Hazard Risk Assessment Program (NHRAP) ftp site [4] for additional HWM-based depth grids and inundation polygons: - Harris County AOIs and Inundation Boundaries [5] - Harris County Depth Grids [6] - Aransas, Nueces, and San Patricio Coastal Depth Grids and Boundaries [7] FEMA notes on these Modeled Preliminary Observations: o Based on observed Water Levels at stream gauges interpolated along rivers, downsampled to 5m resolution DEM o Depth grids updated with new observed peak crest as they become available o Will include High Water Mark information as it becomes available o Extents validated with remote sensing o Use for determining damage levels on specific structures

See also FEMA's journal of mitigation planning and actions related to Harvey [8].

References and related links: [1] FEMA_Depths_3m_v3.zip (39 gb ftp download) [https://data.femadata.com/Region8/Mitigation/Data_Share/] [2] TACC 39gb wget or ftp download [https://web.corral.tacc.utexas.edu/nfiedata/Harvey/flood_data/FEMA_Harvey_Depths_3m.gdb.zip] [3] FEMA map viewer for Hurricane Harvey resources (flood depths is bottom selection in layers list) [https://fema.maps.arcgis.com/apps/webappviewer/index.html?id=50f21538c7bf4e08b9faab430bc237c9] [4] FEMA NHRAP ftp [https://data.femadata.com/FIMA/NHRAP/Harvey/] [5] [https://data.femadata.com/FIMA/NHRAP/Harvey/Harris_AOIandBoundaries.zip] [6] [https://data.femadata.com/FIMA/NHRAP/Harvey/Harris_Mosaic_dgft.zip] [7] [https://data.femadata.com/FIMA/NHRAP/Harvey/Rockport_DG_unclipped.zip] [8] Hurricane Harvey Mitigation Portfolio - FEMA map journal [https://fema.maps.arcgis.com/apps/MapJournal/index.html?appid=70204cf2762d45409553fd9642700b7f]

FP_DFIRM shows areas in Pima County prone to 100-year and shallow 100-year flood events. ZONES A, AE, AH, AO # and AO - ALLUVIAL FAN # comprise the extent of the 100-year floodplain. The tailing numbers in the ZONE AO strings indicate flood depth in feet.ZONE D shows areas that have not been mapped by FEMA (primarily federal and tribal lands). Zone X shows areas that have been mapped but are outside of the 500-year floodplain.ZONE X -SHALLOW 100-YEAR shows the extent of the shallow 100-year floodplain, the 500 year floodplain and Areas protected by levee. The layer FP_ZONEX provides subclassifications for these areas.Note, FP_LOMX can be used to augment FP_DFIRM for large-scale mapping.Also note, FP_DFIRM should be used in conjunction with FP_SS for the floodprone land brochure mailings sent out by PCRFCD on an annual basis.For general FIRM information: See more information.This layer is maintained by Pima County. Click here to visit Pima County's Open Data site. Click here to visit Pima County's GIS Library metadata. PurposeThis layer was developed to show Flood Hazard Zones in Pima County, Arizona.Dataset ClassificationLevel 0 - OpenKnown UsesThis layer is not in any known applications.Known Errors A composite of FEMA maps with different scales and years.ContactPima County - GISdata@pima.govUpdate FrequencyAs Needed

Normally, any FIRM that has associated flood profiles has cross sections. The S_XS table contains information about cross section lines. These lines usually represent the locations of channel surveys performed for input into the hydraulic model used to calculate flood elevations. Sometimes cross sections are interpolated between surveyed cross sections using high accuracy elevation data. Depending on the zone designation (Zone AE, Zone A, etc.), these locations may be shown on Flood Profiles in the FIS report and can be used to cross reference the Flood Profiles to the planimetric depiction of the flood hazards. This information is used in the Floodway Data Tables in the FIS report, as well as on the FIRM panels.Flood hazard and supporting data are developed using specifications for horizontal control consistent with 1:12,000–scale mapping. If you plan to display maps from the National Flood Hazard Layer with other map data for official purposes, ensure that the other information meets FEMA’s standards for map accuracy.The minimum horizontal positional accuracy for base map hydrographic and transportation features used with the NFHL is the NSSDA radial accuracy of 38 feet. USGS imagery and map services that meet this standard can be found by visiting the Knowledge Sharing Site (KSS) for Base Map Standards (420). Other base map standards can be found athttps://riskmapportal.msc.fema.gov/kss/MapChanges/default.aspx. You will need a username and password to access this information.The NFHL data are from FEMA’s Flood Insurance Rate Map (FIRM) databases. New data are added continually. The NFHL also contains map changes to FIRM data made by Letters of Map Revision (LOMRs).The NFHL is stored in North American Datum of 1983, Geodetic Reference System 80 coordinate system, though many of the NFHL GIS web services support the Web Mercator Sphere projection commonly used in web mapping applications.

[Metadata] Tropical storms, hurricanes, and tsunamis create waves that flood low-lying coastal areas. The National Flood Insurance Program (NFIP) produces flood insurance rate maps (FIRMs) that depict flood risk zones referred to as Special Flood Hazard Areas (SFHA) based modeling 1%-annual-chance flood event also referred to as a 100-year flood. The purpose of the FIRM is twofold: (1) to provide the basis for application of regulatory standards and (2) to provide the basis for insurance rating.SFHAs identify areas at risk from infrequent but severe storm-induced wave events and riverine flood events that are based upon historical record. By law (44 Code of Federal Regulations [CFR] 60.3), FEMA can only map flood risk that will be utilized for land use regulation or insurance rating based on historical data, therefore, future conditions with sea level rise and other impacts of climate change are not considered in FIRMs. It is important to note that FEMA can produce Flood Insurance Rate Maps that include future condition floodplains, but these would be considered “awareness” zones and not to be used for regulatory of insurance rating purposes.The State of Hawai‘i 2018 Hazard Mitigation Plan incorporated the results of modeling and an assessment of vulnerability to coastal flooding from storm-induced wave events with sea level rise (Tetra Tech Inc., 2018). The 1% annual-chance-coastal flood zone with sea level rise (1%CFZ) was modeled to estimate coastal flood extents and wave heights for wave-generating events with sea level rise. Modeling was conducted by Sobis Inc. under State of Hawaiʻi Department of Land and Natural Resources Contract No: 64064. The 1%CFZ with 3.2 feet of sea level rise was utilized to assess vulnerability to coastal event-based flooding in mid to - late century.The 1%CFZ with sea level rise would greatly expand the impacts from a 100-year flood event meaning that more coastal land area will be exposed to damaging waves. For example, over 120 critical infrastructure facilities in the City and County of Honolulu, including water, waste, and wastewater systems and communication and energy facilities would be impacted in the 1%CFZ with 3.2 feet of sea level rise (Tetra Tech Inc., 2018). This is double the number of facilities in the SFHA which includes the impacts of riverine flooding.A simplified version of the Wave Height Analysis for Flood Insurance Studies (WHAFIS) extension (FEMA, 2019b) included in Hazus-MH, was used to create the 1% annual chance coastal floodplain. Hazus is a nationally applicable standardized methodology that contains models for estimating potential losses from earthquakes, floods, tsunamis, and hurricanes (FEMA, 2019a). The current 1%-annual-chance stillwater elevations were collected using the most current flood insurance studies (FIS) for each island conducted by FEMA (FEMA, 2004, 2010, 2014, 2015). The FIS calculates the 1%-annual-chance stillwater elevation, wave setup, and wave run-up (called maximum wave crest) at regularly-spaced transects around the islands based on historical data. Modeling for the 1%CFZ used the NOAA 3-meter digital elevation model (DEM) which incorporates LiDAR data sets collected between 2003 and 2007 from NOAA, FEMA, the State of Hawaiʻi Emergency Management Agency, and the USACE (NOAA National Centers for Environmental Information, 2017).Before Hazus was run for future conditions, it was run for the current conditions and compared to the FEMA regulatory floodplain to determine model accuracy. This also helped determine the stillwater elevation for the large gaps between some transects in the FIS. Hazus was run at 0.5-foot stillwater level intervals and the results were compared to the existing Flood Insurance Rate Map (FIRM). The interval of 0.5-feet was chosen as a small enough step to result in a near approximation of the FIRM while not being too impractically narrow to require the testing of dozens of input elevations. The elevation which matched up best was used as the current base flood elevation.Key steps in modeling the projected 1%CFZ with sea level rise include: (1) generating a contiguous (no gaps along the shoreline) and present-day 1%-annual-chance stillwater elevation based on the most recent FIS, (2) elevating the present-day 1%-annual-chance stillwater elevation by adding projected sea level rise heights, and (3) modeling the projected 1%-annual-chance coastal flood with sea level rise in HAZUS using the 1%-annual-chance wave setup and run-up from the FIS. The 1%CFZ extent and depth was generated using the HAZUS 3.2 coastal flood risk assessment model, 3-meter DEM, the FIS for each island, and the IPCC AR5 upper sea level projection for RCP 8.5 scenario for 0.6 feet, 1.0 feet, 2.0 feet, and 3.2 feet of sea level rise above MHHW (IPCC, 2014). The HAZUS output includes the estimated spatial extent of coastal flooding as well as an estimated flood depth map grid for the four sea level rise projections.Using the current floodplain generated with Hazus, the projected 1%-annual-chance stillwater elevation was generated using the four sea level rise projections. This stillwater elevation with sea level rise was used as a basis for modeling. The projected 1%-annual coastal flood with sea level rise was modeled in Hazus using the current 1%-annual-chance wave setup and run-up from the FIS and the projected 1%-annual-chance stillwater elevation with sea level rise. Statewide GIS Program staff extracted individual island layers for ease of downloading. A statewide layer is also available as a REST service, and is available for download from the Statewide GIS geoportal at https://geoportal.hawaii.gov/, or at the Program's legacy download site at https://planning.hawaii.gov/gis/download-gis-data-expanded/#009. For additional information, please refer to summary metadata at https://files.hawaii.gov/dbedt/op/gis/data/coastal_flood_zones_summary.pdf or contact Hawaii Statewide GIS Program, Office of Planning and Sustainable Development, State of Hawaii; PO Box 2359, Honolulu, Hi. 96804; (808) 587-2846; email: gis@hawaii.gov.

The National Flood Hazard Layer (NFHL) is a compilation of GIS data that comprises a nationwide digital Flood Insurance Rate Map. The GIS data and services are designed to provide the user with the ability to determine the flood zone, base flood elevation, and floodway status for a particular location. It also has information about the NFIP communities, map panels, cross sections, hydraulic structures, Coastal Barrier Resource System, and base maps such as road, stream, and public land survey data. Through flood studies, FEMA produces Flood Insurance Study Reports, FIRM Panels, and FIRM Databases. FIRM Databases that become effective are incorporated into the NFHL. Updates to the NFHL are issued through Letters of Map Revision (LOMRs) and Letters of Map Amendment (LOMAs). Continuously updated, the NFHL serves as a Digital Flood Insurance Rate Map representing the current effective flood data for those communities where maps have been digitized. NFHL data can be viewed with widely available GIS software, including freely available programs that work with GIS shapefiles. For more information on the NFHL, see the online resources referenced herein. Using base maps: The minimum horizontal positional accuracy for base map hydrographic and transportation features used with the NFHL is the NSSDA radial accuracy of 38 feet. Letter of Map Amendment (LOMA) point locations are approximate. The location of the LOMA is referenced in the legal description of the letter itself. LOMA points can be viewed in the NFHL Interactive Map on the FEMA GeoPlatform.

[Metadata] Tropical storms, hurricanes, and tsunamis create waves that flood low-lying coastal areas. The National Flood Insurance Program (NFIP) produces flood insurance rate maps (FIRMs) that depict flood risk zones referred to as Special Flood Hazard Areas (SFHA) based modeling 1%-annual-chance flood event also referred to as a 100-year flood. The purpose of the FIRM is twofold: (1) to provide the basis for application of regulatory standards and (2) to provide the basis for insurance rating.SFHAs identify areas at risk from infrequent but severe storm-induced wave events and riverine flood events that are based upon historical record. By law (44 Code of Federal Regulations [CFR] 60.3), FEMA can only map flood risk that will be utilized for land use regulation or insurance rating based on historical data, therefore, future conditions with sea level rise and other impacts of climate change are not considered in FIRMs. It is important to note that FEMA can produce Flood Insurance Rate Maps that include future condition floodplains, but these would be considered “awareness” zones and not to be used for regulatory of insurance rating purposes.The State of Hawai‘i 2018 Hazard Mitigation Plan incorporated the results of modeling and an assessment of vulnerability to coastal flooding from storm-induced wave events with sea level rise (Tetra Tech Inc., 2018). The 1% annual-chance-coastal flood zone with sea level rise (1%CFZ) was modeled to estimate coastal flood extents and wave heights for wave-generating events with sea level rise. Modeling was conducted by Sobis Inc. under State of Hawaiʻi Department of Land and Natural Resources Contract No: 64064. The 1%CFZ with 3.2 feet of sea level rise was utilized to assess vulnerability to coastal event-based flooding in mid to - late century.The 1%CFZ with sea level rise would greatly expand the impacts from a 100-year flood event meaning that more coastal land area will be exposed to damaging waves. For example, over 120 critical infrastructure facilities in the City and County of Honolulu, including water, waste, and wastewater systems and communication and energy facilities would be impacted in the 1%CFZ with 3.2 feet of sea level rise (Tetra Tech Inc., 2018). This is double the number of facilities in the SFHA which includes the impacts of riverine flooding.A simplified version of the Wave Height Analysis for Flood Insurance Studies (WHAFIS) extension (FEMA, 2019b) included in Hazus-MH, was used to create the 1% annual chance coastal floodplain. Hazus is a nationally applicable standardized methodology that contains models for estimating potential losses from earthquakes, floods, tsunamis, and hurricanes (FEMA, 2019a). The current 1%-annual-chance stillwater elevations were collected using the most current flood insurance studies (FIS) for each island conducted by FEMA (FEMA, 2004, 2010, 2014, 2015). The FIS calculates the 1%-annual-chance stillwater elevation, wave setup, and wave run-up (called maximum wave crest) at regularly-spaced transects around the islands based on historical data. Modeling for the 1%CFZ used the NOAA 3-meter digital elevation model (DEM) which incorporates LiDAR data sets collected between 2003 and 2007 from NOAA, FEMA, the State of Hawaiʻi Emergency Management Agency, and the USACE (NOAA National Centers for Environmental Information, 2017).Before Hazus was run for future conditions, it was run for the current conditions and compared to the FEMA regulatory floodplain to determine model accuracy. This also helped determine the stillwater elevation for the large gaps between some transects in the FIS. Hazus was run at 0.5-foot stillwater level intervals and the results were compared to the existing Flood Insurance Rate Map (FIRM). The interval of 0.5-feet was chosen as a small enough step to result in a near approximation of the FIRM while not being too impractically narrow to require the testing of dozens of input elevations. The elevation which matched up best was used as the current base flood elevation.Key steps in modeling the projected 1%CFZ with sea level rise include: (1) generating a contiguous (no gaps along the shoreline) and present-day 1%-annual-chance stillwater elevation based on the most recent FIS, (2) elevating the present-day 1%-annual-chance stillwater elevation by adding projected sea level rise heights, and (3) modeling the projected 1%-annual-chance coastal flood with sea level rise in HAZUS using the 1%-annual-chance wave setup and run-up from the FIS. The 1%CFZ extent and depth was generated using the HAZUS 3.2 coastal flood risk assessment model, 3-meter DEM, the FIS for each island, and the IPCC AR5 upper sea level projection for RCP 8.5 scenario for 0.6 feet, 1.0 feet, 2.0 feet, and 3.2 feet of sea level rise above MHHW (IPCC, 2014). The HAZUS output includes the estimated spatial extent of coastal flooding as well as an estimated flood depth map grid for the four sea level rise projections.Using the current floodplain generated with Hazus, the projected 1%-annual-chance stillwater elevation was generated using the four sea level rise projections. This stillwater elevation with sea level rise was used as a basis for modeling. The projected 1%-annual coastal flood with sea level rise was modeled in Hazus using the current 1%-annual-chance wave setup and run-up from the FIS and the projected 1%-annual-chance stillwater elevation with sea level rise. Statewide GIS Program staff extracted individual island layers for ease of downloading. A statewide layer is also available as a REST service, and is available for download from the Statewide GIS geoportal at https://geoportal.hawaii.gov/, or at the Program's legacy download site at https://planning.hawaii.gov/gis/download-gis-data-expanded/#009. For additional information, please refer to summary metadata at https://files.hawaii.gov/dbedt/op/gis/data/coastal_flood_zones_summary.pdf or contact Hawaii Statewide GIS Program, Office of Planning and Sustainable Development, State of Hawaii; PO Box 2359, Honolulu, Hi. 96804; (808) 587-2846; email: gis@hawaii.gov.

fp_bfe displays the flood hazard elevation contours that indicate the water surface elevation resulting from a flood that has a 1% chance of equaling or exceeding that level in any given year (100-year flood). See more information.This layer is maintained by Pima County. Click here to visit Pima County's Open Data site. Click here to visit Pima County's GIS Library metadata. PurposeThis layer was developed to show FEMA flood zone cross sections in Pima County, Arizona.Dataset ClassificationLevel 0 - OpenKnown UsesThis layer is not in any known applications.Known Errors Unlettered FEMA Cross-sections are identified with a -99 value in the CS_ALPHA field. Unlettered cross-sections are not displayed on MapGuide.12/2013: While this layer is maintained as a Shapefile, the coverage format is still required for certain nightly processing. See Steve Whitney. - FEMA floodplain data extraction processContactPima County - GISdata@pima.govUpdate FrequencyAs Needed

This is a dataset download, not a document. The Open button will start the download.This data layer is an element of the Oregon GIS Framework. This feature dataset contains the following feature classes: 1. FEMA Flood Insurance Study base flood elevation (BFE) lines: The FEMA_BFE feature class is a compilation of FEMA Flood Insurance Study base flood elevation (BFE) lines for the state of Oregon. The FEMA Flood Insurance Study base flood elevation (BFE) lines were derived from Digital Flood Insurance Rate Maps and georeferenced paper Flood Insurance Rate Maps. 2. FEMA Flood Insurance Study inundation zones: The FEMA_FLD_HAZ_AR feature class is a compilation of FEMA Flood Insurance Study inundation zones for the state of Oregon. The FEMA Flood Insurance Study inundation zones were derived from Digital Flood Insurance Rate Maps and georeferenced paper Flood Insurance Rate Maps. 3. FEMA Letter of Map Change (LOMC) Locations: The FEMA_LOMC feature class is a compilation of FEMA Letter of Map Change (LOMC) Locations for the state of Oregon. The FEMA Letter of Map Change (LOMC) Locations were downloaded from the FEMA Map Service Center Website. The LOMC points were precisely located using county-level assessor data, orthoimagery, and lidar hillshades. 4. FEMA Flood Insurance Study profile baselines: The FEMA_PROFIL_BASLN feature class is a compilation of FEMA Flood Insurance Study profile baselines for the state of Oregon. The FEMA Flood Insurance Study profile baselines were derived from Digital Flood Insurance Rate Maps and paper Flood Insurance Rate Maps. 5. FEMA Flood Insurance Study cross section (XS) lines: The FEMA_XS feature class is a compilation of FEMA Flood Insurance Study cross section (XS) lines for the state of Oregon. The FEMA Flood Insurance Study cross section (XS) lines were derived from Digital Flood Insurance Rate Maps and paper Flood Insurance Rate Maps. See feature class metadata for detailed information about each feature class.

Esri ArcGIS Online (AGOL) Imagery Layer for accessing the Maryland Coast Smart - Climate Ready Action Boundary (CRAB) Coastal - Flood Depth Grid data product.Maryland Coast Smart - Climate Ready Action Boundary (CRAB) Coastal - Flood Depth Grid consists of a flood depth grid image service depicting the Climate Ready Action Boundary (CRAB) for the coastal areas throughout the State of MarylandThe Maryland Coast Smart - Climate Ready Action Boundary (CRAB) Coastal - Flood Depth Grid raster layer was created using a GIS spatial analysis model, unique for each county in the State of Maryland. Coastal counties follow an analysis methodology that incorporates FEMA Stillwater wave action as it is understood from the FEMA identified VE zones. A Water Surface Elevation (WSE) and Still Water Elevation (SWEL) rasters are used as the baseline to identify existing water depths within each county. For all flood zones that are not classified as VE the WSE three feet was added to reflect a three-foot rise in the base flood elevations. For those WSEs falling within a FEMA floodplain identified V Zone, six feet was added (three feet for the increase in flood elevations for the CS-CRAB, and 3 feet to compensate for the minimum of 3 foot wave action typically mapped by FEMA) / wave heights greater than 3 feet were reduced to the 3 foot minimum for consistency across the shoreline. The newly calculated WSE plus three datasets were then converted to points and merged. Next, an Inverse Distance Weighted (IDW) Interpolation was used to compute the proportional weighted values between the WSE point locations based on proximity. The DEM for each county is then subtracted from the new IDW raster in order to show precise water locations as they relate to the land elevation, producing a freeboard depth grid representing the depth of flood waters above the existing ground elevation given a 3 foot increase in water level. A course resolution QAQC was applied to remove “islands” of data associated with DEM inaccuracies and other elevation anomalies. The analysis was run at a 1 ft x 1 ft raster resolution. The DEM accuracy for each county varies based what is currently available. Here the breakdown of DEM accuracy for each county used in this project: Anne Arundel County DEM year is 2017 and horizontal resolution is 1ft. Baltimore County DEM year is 2015 and horizontal resolution is 2.5ft. Baltimore City DEM year is 2015 and horizontal resolution is 0.7m. Calvert County DEM year is 2017 and horizontal resolution is 1ft. Caroline County DEM year is 2013 and horizontal resolution is 3.125ft. Cecil county DEM year is 2013 and horizontal resolution is 0.6m. Charles County DEM year is 2014 and horizontal resolution is 0.9m. Dorchester County DEM year is 2013 and horizontal resolution is 0.9m. Harford County DEM is 2013 and horizontal accuracy is 1.5m. Kent County DEM year is 2015 and horizontal resolution is 0.7m. Prince George’s County DEM year is 2014 and horizontal resolution is 0.7m. Queen Anne’s County DEM year is 2013 and horizontal resolution is 0.6m. Somerset County DEM year is 2012 and horizontal accuracy is 1m. St Mary’s County DEM year is 2014 and Horizontal accuracy is 0.9m. Talbot County DEM year is 2015 and Horizontal accuracy is 0.7m. Wicomico County DEM year is 2012 and horizontal accuracy is 1m. Worchester County DEM year is 2011 and horizontal accuracy is 1m.The Maryland Coast Smart - Climate Ready Action Boundary (CRAB) Coastal - Flood Depth Grid data was created by the Maryland Environmental Service (MES) in partnership with the Maryland Department of Environment (MDE) and the Maryland Coast Smart Council, under the guidance of the Maryland Department of Natural Resource (DNR).For additional information, contact MDOT SHA OIT Enterprise Information Services:Email: GIS@mdot.maryland.gov

The Federal Emergency Managment Agency and the MNDNR produce Digital Flood Insurance Rate Maps (DFIRM) for selected counties in the state. These maps are often referred to as FEMA Floodplain maps.

A DFIRM is the offical digital map of a community on which FEMA has delineated the special flood hazard areas, i.e., the floodplain areas where flood insurance is required for loans and where communities will administer floodplain regulations. (Note: Communities may regulate additional flood prone areas that are not on the FIRM).

Here are some of the feature classes included in the MNDNR's publication of the DFIRM Dataset:

FEMA DFIRM Base Flood Elevations
The Base Flood Elevation (BFE) table is required for any digital data where BFE lines will be shown on the corresponding Flood Insurance Rate Map (FIRM). Normally, if there are any riverine AE zones, BFE lines are required. The BFE table contains information about the BFEs within a study area. A spatial file with locational information also corresponds with this data table. BFE lines indicate the rounded whole-foot water-surface elevation of the 1-percent-annual-chance flood. The spatial elements representing BFE features are lines extending from Special Flood Hazard Area (SFHA) boundary to SFHA boundary. The BFE lines will have no visible gaps or overshoots between the SFHA boundary and the end of the BFE line at the publication scale of the DFIRM. However, the ends of the BFE lines are not necessarily snapped precisely to the SFHA boundary. Each BFE is represented by a single line. While BFE lines are depicted as wavy lines on the hardcopy FIRM, they should be primarily straight lines in the spatial data, although they may bend consistent with procedures described in Volume 1 of these Guidelines.

FEMA DFIRM Flood Hazard Zones
FEMA flood hazard delineations are used by FEMA to designate the SFHA and for insurance rating purposes. These data are the flood hazard areas that are or will be depicted on the FIRM.

FEMA DFIRM Panel Scheme Polygons
This layer contains information about the FIRM panel areas. The spatial entities representing FIRM panels are polygons. The polygon for the FIRM panel corresponds to the panel neatlines. As a result, the panels are generally rectangular. In situations where a portion of a panel lies outside of the jurisdiction being mapped, the user must refer to the S_POL_AR table to determine the portion of the panel area where the DFIRM database shows the effective flood hazard data for the mapped jurisdiction.

FEMA DFIRM Cross Sections
FEMA Cross Sections are required for any Digital Flood Insurance Rate Map database where cross sections are shown on the FIRM. Normally any FIRM that has associated flood profiles has cross sections. The corresponding attribute table contains information about cross section lines. A spatial file with locational information also corresponds with this data table. These lines represent the locations of channel surveys performed for input into the hydraulic model used to calculate flood elevations. These locations are also shown on the Flood Profiles in the Flood Insurance Study (FIS) report and can be used to cross reference the Flood Profiles to the planimetric depiction of the flood hazards. All cross sections for which a spatial location is available should be included in this table. The spatial elements representing cross sections are lines generally extending from outside the floodplain, across the entire floodplain and out the other side. Each cross section should be represented by a single line feature without the hexagons shown on each end on the hardcopy map. The location and shape of the lines should depict as accurately as possible the position of the cross section used. This is a modified Standard DFIRM Database table that includes Standard DFIRM Database items and Enhanced Database items. All items after SOURCE_CIT are Enhanced. The Enhanced DFIRM Database must contain all modeled cross sections, whether they are printed on the FIRM or not.

Extensive information regarding the source data can be found in these two documents:
FEMA DFIRM Doc Appendix L Part A.pdf
FEMA DFIRM Doc Appendix L Part B.pdf

Geospatial data about Erie County, New York FEMA Base Flood Elevation. Export to CAD, GIS, PDF, CSV and access via API.

This layer shows the flood zones as defined by FEMA.

© FEMA This layer is a component of FEMA 100 Year Flood Zones.

This map document contains the 100 year flood zones as defined by FEMA for Kerr County, Texas.

© City of Kerrville, Texas, FEMA

Purpose: This is a web map used for a situational awareness viewer. Click on links below for more information, this is just a summary of the layers in this map as of 09/14/2018.Live Data Live Feed - Storm Reports (NOAA) - This map contains continuously updated U.S. tornado reports, wind storm reports and hail storm reports. You can click on each to receive information about the specific location and read a short description about the issue. Live Feed - Observed Weather (NOAA METAR) - Current wind and weather conditions at all METAR stations.Live Feed: Open Shelters (FEMA / Red Cross National Shelter System) - his web service displays data from the FEMA National Shelter System database. The FEMA NSS database is synchronized every morning with the American Red Cross shelter database. After this daily refresh, FEMA GIS connects every 20 minutes to the FEMA NSS database looking for any shelter updates that occur throughout the day in the the FEMA NSS.Live Feed: Active Hurricanes - Hurricane tracks and positions provide information on where the storm has been, where is it going, where it is currently located and the category as defined by wind speed. This data is provided by NOAA National Hurricane Center (NHC).Live Feed Action Level Stream Gauges (USGS) - This map service shows those gauges from the Live Stream Gauge layer that are currently flooding. It only includes those gauges where flood stages have been defined by the contributing agencies. Action stage represents the river depth at which the agency begins preparing for a flood and taking mitigative action.Live Feed: USA Short-Term Weather Warnings - This layer presents continuously updated US weather warnings. You can click on each to receive information about the specific location and read a short description about the issue. Each layer is updated every minute with data provided by NOAA’s National Weather Service - http://www.nws.noaa.gov/regsci/gis/shapefiles/.Live Feed: Power Outages - Current power outage data reported by the EARSS system.Live Feed: Radar (NOAA) - Quality Controlled 1km x 1km CONUS Radar Base Reflectivity. This data is provided by Mutil-Radar-Multi-Sensor (MRMS) algorithm.Flood Prediction / Simulation (Created on 09/13 by Pacific Northwest National Laboratory RIFT Model) - Pacific Northwest National Laboratory RIFT Model: The simulations, based on NOAA weather forecasts, are used to improve understanding of the storm and its potential flood impacts. The simulations were created with PNNL's Rapid Inundation Flood Tool, a two-dimensional hydrodynamic computer model.Base Data - FEMA National Flood Hazard Layer - The National Flood Hazard Layer (NFHL) dataset represents the current effective flood data for the country, where maps have been modernized. It is a compilation of effective Flood Insurance Rate Map (FIRM) databases and Letters of Map Change (LOMCs). The NFHL is updated as studies go effective. For more information, visit FEMA's Map Service Center (MSC). Base Data - Storm Surge Scenarios (NOAA) - This mapping service displays near worst case storm surge flooding (inundation) scenarios for the Gulf and Atlantic coasts. This map service was derived from an experimental storm surge data product developed by the National Hurricane Center (NHC).

This layer was developed by the Research & Analytics Division of the Atlanta Regional Commission and represents the 100-year and 500-year floodplain data as delineated on Flood Insurance Rate Maps (FIRMs) published by FEMA. Features captured from the paper FIRMs include floodplain boundaries, political boundaries, FIRM panel areas, and USGS 7.5-minute quadrangle boundaries. Potential applications of this "Q3" flood data include floodplain management, hazards analysis and risk assessment. In addition, the risk zones serve to establish premium rates for flood insurance offered through the National Flood Insurance Program. For more information, go to https://msc.fema.gov.Attributes:FIPS Standard 5-digit State and County FIPS codes. Definition source is from Federal Information Processing Standard (FIPS), National Institute of Standards & Technology (NIST); first 2 digits for state, last 3 digits for county.COMMUNITY Identifies a county, city, or other community responsible for flood plain management. Numeric value assigned by FEMA,(0..9999).FIRM_PANEL Eleven-digit alpha-numeric code identifies portion of community covered or not covered by a FIRM panel. Code comprises a unique alpha-numeric sequence based on FIPS and FEMA Community and Panel identification.QUAD USGS 7.5-minute quadrangle identifier.ZONE Flood hazard zone designation. Multiple Codes refer to "Q3 Flood Data Specifications" VALUES DESCRIPTION V An area inundated by 100-year flooding with velocity hazard (wave action); no Base Flood Elevation (BFEs) have been determined. VE An area inundated by 100-year flooding with velocity hazard (wave action); BFEs have been determined. A An area inundated by 100-year flooding, for which no BFEs have been determined. AE An area inundated by 100-year flooding, for which BFEs have been determined. AO An area inundated by 100-year flooding (usually sheet flow on sloping terrain), for which average depths have been determined; flood depths range from 1 to 3 feet. AOVEL An alluvial fan inundated by 100-year flooding (usually sheet flow on sloping terrain), for which average flood depths and velocities have been determined; flood depths range from 1 to 3 feet. AH An area inundated by 100-year flooding (usually an area of ponding), for which BFEs have been determined; flood depths range from 1 to 3 feet. A99 An area inundated by 100-year flooding, for which no BFEs have been determined. This is an area to be protected from the 100-year flood by a Federal flood protection system under construction. D An area of undetermined but possible flood hazards. AR An area inundated by flooding, for which BFEs or average depths have been determined. This is an area that was previously, and will again, be protected from the 100-year flood by a Federal flood protection system whose restoration is Federally funded and underway. X500 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 the 100-year flooding. X An area that is determined to be outside the 100- and 500-year floodplains. 100IC 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. BFEs are not shown in this area, although they may be reflected on the corresponding profile. 500IC 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. FWIC 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. FPQ 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 100-year flooding for which no BFEs have been determined.FLOODWAY Channel, river or watercourse reserved for flood discharge. Multiple Codes refer to "Q3 Flood Data Specifications".COBRA Undeveloped Coastal Barrier Area. Multiple Codes refer to "Q3 Flood Data Specifications".SFHA In/Out of flood zone designation, determined from data topology. VALUES DESCRIPTION IN An area designated as within a "Special Flood Hazard Area" (or SFHA) on a FIRM. This is an area inundated by 100-year flooding for which no BFEs or velocity may have been determined. No distinctions are made between the different flood hazard zones that may be included within the SFHA. These may include Zones A, AE, AO, AH, A99, AR, V, or VE. OUT 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; an area protected by levees from 100-year flooding; or an area that is determined to be outside the 100- and 500-year floodplains. No distinctions are made between these different conditions. These may include both shaded and unshaded areas of Zone X. ANI An area that is located within a community or county that is not mapped on any published FIRM. UNDES A body of open water, such as a pond, lake ocean, etc., located within a community's jurisdictional limits, that has no defined flood hazard.SYMBOL Polygon shade symbols for graphic output, based on polygon codes. Multiple Codes refer to "Q3 Flood Data Specifications"PANEL_TYP Type of FIRM panel represented. Multiple Codes refer to "Q3 Flood Data Specifications".ST_FIPS State FIPS codeCO_FIPS County FIPS codeSource: Federal Emergency Management Agency (FEMA), Atlanta Regional CommissionDate: 1998

[Metadata] Tropical storms, hurricanes, and tsunamis create waves that flood low-lying coastal areas. The National Flood Insurance Program (NFIP) produces flood insurance rate maps (FIRMs) that depict flood risk zones referred to as Special Flood Hazard Areas (SFHA) based modeling 1%-annual-chance flood event also referred to as a 100-year flood. The purpose of the FIRM is twofold: (1) to provide the basis for application of regulatory standards and (2) to provide the basis for insurance rating.SFHAs identify areas at risk from infrequent but severe storm-induced wave events and riverine flood events that are based upon historical record. By law (44 Code of Federal Regulations [CFR] 60.3), FEMA can only map flood risk that will be utilized for land use regulation or insurance rating based on historical data, therefore, future conditions with sea level rise and other impacts of climate change are not considered in FIRMs. It is important to note that FEMA can produce Flood Insurance Rate Maps that include future condition floodplains, but these would be considered “awareness” zones and not to be used for regulatory of insurance rating purposes.The State of Hawai‘i 2018 Hazard Mitigation Plan incorporated the results of modeling and an assessment of vulnerability to coastal flooding from storm-induced wave events with sea level rise (Tetra Tech Inc., 2018). The 1% annual-chance-coastal flood zone with sea level rise (1%CFZ) was modeled to estimate coastal flood extents and wave heights for wave-generating events with sea level rise. Modeling was conducted by Sobis Inc. under State of Hawaiʻi Department of Land and Natural Resources Contract No: 64064. The 1%CFZ with 3.2 feet of sea level rise was utilized to assess vulnerability to coastal event-based flooding in mid to - late century.The 1%CFZ with sea level rise would greatly expand the impacts from a 100-year flood event meaning that more coastal land area will be exposed to damaging waves. For example, over 120 critical infrastructure facilities in the City and County of Honolulu, including water, waste, and wastewater systems and communication and energy facilities would be impacted in the 1%CFZ with 3.2 feet of sea level rise (Tetra Tech Inc., 2018). This is double the number of facilities in the SFHA which includes the impacts of riverine flooding.A simplified version of the Wave Height Analysis for Flood Insurance Studies (WHAFIS) extension (FEMA, 2019b) included in Hazus-MH, was used to create the 1% annual chance coastal floodplain. Hazus is a nationally applicable standardized methodology that contains models for estimating potential losses from earthquakes, floods, tsunamis, and hurricanes (FEMA, 2019a). The current 1%-annual-chance stillwater elevations were collected using the most current flood insurance studies (FIS) for each island conducted by FEMA (FEMA, 2004, 2010, 2014, 2015). The FIS calculates the 1%-annual-chance stillwater elevation, wave setup, and wave run-up (called maximum wave crest) at regularly-spaced transects around the islands based on historical data. Modeling for the 1%CFZ used the NOAA 3-meter digital elevation model (DEM) which incorporates LiDAR data sets collected between 2003 and 2007 from NOAA, FEMA, the State of Hawaiʻi Emergency Management Agency, and the USACE (NOAA National Centers for Environmental Information, 2017).Before Hazus was run for future conditions, it was run for the current conditions and compared to the FEMA regulatory floodplain to determine model accuracy. This also helped determine the stillwater elevation for the large gaps between some transects in the FIS. Hazus was run at 0.5-foot stillwater level intervals and the results were compared to the existing Flood Insurance Rate Map (FIRM). The interval of 0.5-feet was chosen as a small enough step to result in a near approximation of the FIRM while not being too impractically narrow to require the testing of dozens of input elevations. The elevation which matched up best was used as the current base flood elevation.Key steps in modeling the projected 1%CFZ with sea level rise include: (1) generating a contiguous (no gaps along the shoreline) and present-day 1%-annual-chance stillwater elevation based on the most recent FIS, (2) elevating the present-day 1%-annual-chance stillwater elevation by adding projected sea level rise heights, and (3) modeling the projected 1%-annual-chance coastal flood with sea level rise in HAZUS using the 1%-annual-chance wave setup and run-up from the FIS. The 1%CFZ extent and depth was generated using the HAZUS 3.2 coastal flood risk assessment model, 3-meter DEM, the FIS for each island, and the IPCC AR5 upper sea level projection for RCP 8.5 scenario for 0.6 feet, 1.0 feet, 2.0 feet, and 3.2 feet of sea level rise above MHHW (IPCC, 2014). The HAZUS output includes the estimated spatial extent of coastal flooding as well as an estimated flood depth map grid for the four sea level rise projections.Using the current floodplain generated with Hazus, the projected 1%-annual-chance stillwater elevation was generated using the four sea level rise projections. This stillwater elevation with sea level rise was used as a basis for modeling. The projected 1%-annual coastal flood with sea level rise was modeled in Hazus using the current 1%-annual-chance wave setup and run-up from the FIS and the projected 1%-annual-chance stillwater elevation with sea level rise. Statewide GIS Program staff extracted individual island layers for ease of downloading. A statewide layer is also available as a REST service, and is available for download from the Statewide GIS geoportal at https://geoportal.hawaii.gov/, or at the Program's legacy download site at https://planning.hawaii.gov/gis/download-gis-data-expanded/#009. For additional information, please refer to summary metadata at https://files.hawaii.gov/dbedt/op/gis/data/coastal_flood_zones_summary.pdf or contact Hawaii Statewide GIS Program, Office of Planning and Sustainable Development, State of Hawaii; PO Box 2359, Honolulu, Hi. 96804; (808) 587-2846; email: gis@hawaii.gov.

This layer includes only building footprints where final elevation certificates are available, with elevations reported in the vertical datum provided on the elevation certificate (NAVD 1988 or NGVD 1929).Elevation certificates were collected from the following 10 localities: (1)Chesapeake, (2)Franklin, (3)Hampton, (4)James City County, (5)Newport News, (6)Norfolk, (7)Portsmouth, (8)Southampton County, (9)Virginia Beach, and (10)York County. All elevation certificate information was entered by HRPDC staff. Localities included in the current inventory were able to provide digital elevation certificate copies. This inventory is not complete for the region, and elevation certificates will continue to be added to the database when available. Building footprints are courtesy of VGIN map service and locality GIS departments. Building attributes and parcels are courtesy of the Hampton Roads Regional Parcels layer and locality GIS departments. Current flood zones are courtesy of the FEMA National Flood Hazard Layer, with base flood elevations reported in NAVD 1988 where available. Created 2/8/2019

Polygon boundaries of FEMA's 100 Year FloodplainData Development:FEMA updated this layer in 2007 and the Philadelphia City Planning Commission received it in 2009.

© Pauline Loughlin Philadelphia City Planning Commission

This layer is sourced from gis.phila.gov.

This layer includes only building footprints where final elevation certificates are available, with all elevations reported in NAVD 1988. Where necessary, conversions from NGVD 1929 to NAVD 1988 were completed using the VERTCON v2.1 program (NOAA NGS, 2018). Elevation certificates were collected from the following 10 localities: (1)Chesapeake, (2)Franklin, (3)Hampton, (4)James City County, (5)Newport News, (6)Norfolk, (7)Portsmouth, (8)Southampton County, (9)Virginia Beach, and (10)York County. All elevation certificate information was entered by HRPDC staff. Localities included in the current inventory were able to provide digital elevation certificate copies. This inventory is not complete for the region, and elevation certificates will continue to be added to the database when available. Building footprints are courtesy of VGIN map service and locality GIS departments. Building attributes and parcels are courtesy of the Hampton Roads Regional Parcels layer and locality GIS departments. Current flood zones are courtesy of the FEMA National Flood Hazard Layer, with base flood elevations reported in NAVD 1988 where available. Created 2/8/2019