This dataset comes from the FEMA S_Fld_Haz_Ar table. The S_Fld_Haz_Ar table contains information about the flood hazards within the flood risk project area. A spatial file with location information also corresponds with this data table. These zones are used by FEMA to designate the SFHA and for insurance rating purposes. These data are the regulatory flood zones designated by FEMA. A spatial file with location information also corresponds with this data table.This information is needed for the following tables in the FIS report: Flooding Sources Included in this FIS report, and Summary of Hydrologic and Hydraulic Analyses.The spatial elements representing the flood zones are polygons. The entire area of the jurisdiction(s) mapped by the FIRM should have a corresponding flood zone polygon. There is one polygon for each contiguous flood zone designated.FEMA Regulatory Floodway are flood zone polygons marked as a regulatory floodway.FEMA 100 year are flood zone polygons where there is a 1% Annual Chance, also known as the 100 year.FEMA 500 year are flood zone polygons where there is a 0.2% Annual Chance, also known as the 500 year.FEMA minimal flood hazard zone polygons.This map is not intended for insurance rating purposes and is for information only. This map is a representation and approximation of the relative location of geographic information, land marks and physical addresses. The map may not be 100% accurate in locating your address. The floodplains shown on this mapping tool are those delineated on the Federal Emergency Management Agency’s (FEMA) Digital Flood Insurance Rate Map (DFIRM or floodplain map) for Montgomery County. This map is not an official FEMA Digital Flood Insurance Rate Map. The effective DFIRMs are produced, maintained, and published by FEMA and not by Montgomery County. Official determinations are provided by FEMA.

Geospatial data about Montgomery County, Texas Flood Plain Area. Export to CAD, GIS, PDF, CSV and access via API.

Montgomery County, Tx floodplain viewer showing the National Flood Hazard Layer that is revised by FEMA. Description from FEMA: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.

The National Flood Hazard Layer (NFHL) data incorporates all Flood Insurance Rate Map (FIRM) databases published by the Federal Emergency Management Agency (FEMA), and any Letters Of Map Revision (LOMRs) that have been issued against those databases since their publication date. It is updated on a monthly basis. The FIRM Database is the digital, geospatial version of the flood hazard information shown on the published paper FIRMs. The FIRM Database depicts flood risk information and supporting data used to develop the risk data. The primary risk classifications used are the 1-percent-annual-chance flood event, the 0.2-percent-annual-chance flood event, and areas of minimal flood risk. The FIRM Database is derived from Flood Insurance Studies (FISs), previously published FIRMs, flood hazard analyses performed in support of the FISs and FIRMs, and new mapping data, where available. The FISs and FIRMs are published by FEMA. The NFHL is available as State or US Territory data sets. Each State or Territory data set consists of all FIRM Databases and corresponding LOMRs available on the publication date of the data set. The specification for the horizontal control of FIRM Databases is consistent with those required for mapping at a scale of 1:12,000. This file is georeferenced to the Earth's surface using the Geographic Coordinate System (GCS) and North American Dataum of 1983 (NSRS-2007).

This data is hosted at, and may be downloaded or accessed from PASDA, the Pennsylvania Spatial Data Access Geospatial Data Clearinghouse http://www.pasda.psu.edu/uci/DataSummary.aspx?dataset=2292

After the federal government passed the Clean Water Act in 1972, MNCPPC contracted a series of floodplain studies throughout Montgomery County from the early seventies through the late eighties. These studies used the same rainfall assumptions used today in the FEMA DFIRM floodplain maps. The difference is that the MNCPPC floodplain studies include both an existing conditions analysis but also the ultimate zoning buildout floodplain analysis. This GIS layer represents the ultimate buildout floodplain analysis. As such, this floodplain is generally the most conservative for any area of the County. DPS is in charge of maintaining this layer as it's starting point from which subsequent floodplain amendments are lodged. Various cross sections of this floodplain GIS layer are tagged to a scanned analysis document which can be viewed from the popup. Aside from some of these later floodplain amendments, this original MNCPPC floodplain remains in effect for most of the county's regulatory projects.For more information, contact: GIS Manager Information Technology & Innovation (ITI) Montgomery County Planning Department, MNCPPC T: 301-650-5620

Exercise OnlyPurpose and Audience:The purpose of this map is to summarize the potential impact of a flood hazard in Montgomery County, Maryland. The map shows areas within the flood hazard zone and their overall vulnerability based on Social Vulnerability Index (SoVI). This map also includes an Enriched Flood Hazard layer that shows statistics on endangered households and vulnerable populations within the flood hazard area. This map is intended as a resource for the Montgomery County emergency management agency, for preparedness planning and assessment of the risk to people and property in the county. Layers and Data Sources:

The 2014 SoVI layer was obtained from the ATSDR website: https://svi.cdc.gov/SVIDataToolsDownload.html. It ranks each census tract’s vulnerability based on socioeconomic, minority status/language, household composition, and housing transportation statistics. This layer shows the total vulnerability percentile ranking within the state, 0 – 1, where 1 is the highest social vulnerability.Fire Stations, Hospitals, Nusing Homes, Public Schools, Power Plants and Substations layers were obtained from the Homeland Infrastructure Foundation-Level Data (HIFLD) Open Data Portal: https://hifld-dhs-gii.opendata.arcgis.com/. The Police Station layer was obtained from the Maryland Open Data Portal: https://data.maryland.gov/Public-Safety/MD-iMAP-Maryland-Police-County-Police-Stations/ng3f-pf6x. These layers represent valuable and vulnerable populations and facilities (i.e. Nusing Homes, Public Schools), as well as resources for responding to a disaster (Police Stations, Fire Stations, Hospitals). The Overall Place Vulnerability layer was created using the SoVI layer and data obtained from the FEMA Flood Map Service Center: http://msc.fema.gov/portal/advanceSearch. Overall Place Vulnerability was determined by the intersection of Special Flood Hazard Areas in the FEMA National Flood Hazard Layer and tracts with high social vulnerability, because high SoVI indicates the area may be more adversely affected by a hazard and less resilient in the aftermath. Areas where flood zones intersected tracts with a SoVI total percentile ranking greater than 0.80 were designated as “High”overall place vulnerability, because these tracts are more vulnerable than 80% of tracts in the state. Areas where flood zones intersected tracts with SoVi ranking between 0.60 and 0.80 were designated “Medium-High” overall place vulnerability. The product of this analysis was an Overall Place Vulnerability layer. The US National Grid (USNG) layer and Topographic basemap serve as reference and were obtained from ESRI.

The Digital Flood Insurance Rate Map (DFIRM) Database depicts flood risk information and supporting data used to develop risk data.

The primary risk classifications used are the 1-percent-annual-chance flood event, the 0.2-percent-annual- chance flood event, and areas of minimal flood risk. The DFIRM Database is derived from Flood Insurance Studies (FISs), previously published Flood Insurance Rate Maps (FIRMs), flood hazard analyses performed in support of the FISs and FIRMs, and new mapping data, where available. The FISs and FIRMs are published by the Federal Emergency Management Agency (FEMA). The FIRM is the basis for floodplain management, mitigation, and insurance activities for the National Flood Insurance Program (NFIP). Insurance applications include enforcement of the mandatory purchase requirement of the Flood Disaster Protection Act, which "... requires the purchase of flood insurance by property owners who are being assisted by Federal programs or by Federally supervised, regulated or insured agencies or institutions in the acquisition or improvement of land facilities located or to be located in identified areas having special flood hazards, " Section 2 (b) (4) of the Flood Disaster Protection Act of 1973. In addition to the identification of Special Flood Hazard Areas (SFHAs), the risk zones shown on the FIRMs are the basis for the establishment of premium rates for flood coverage offered through the NFIP. The DFIRM Database presents the flood risk information depicted on the FIRM in a digital format suitable for use in electronic mapping applications. The DFIRM database is a subset of the Digital FIS database that serves to archive the information collected during the FIS. For more information, contact: GIS Manager Information Technology & Innovation (ITI) Montgomery County Planning Department, MNCPPC T: 301-650-5620

The Digital Flood Insurance Rate Map (DFIRM) Database depicts flood risk information and supporting data used to develop risk data. The primary risk classifications used are the 1-percent-annual-chance flood event, the 0.2-percent-annual- chance flood event, and areas of minimal flood risk. The DFIRM Database is derived from Flood Insurance Studies (FISs), previously published Flood Insurance Rate Maps (FIRMs), flood hazard analyses performed in support of the FISs and FIRMs, and new mapping data, where available. The FISs and FIRMs are published by the Federal Emergency Management Agency (FEMA). The FIRM is the basis for floodplain management, mitigation, and insurance activities for the National Flood Insurance Program (NFIP). Insurance applications include enforcement of the mandatory purchase requirement of the Flood Disaster Protection Act, which "... requires the purchase of flood insurance by property owners who are being assisted by Federal programs or by Federally supervised, regulated or insured agencies or institutions in the acquisition or improvement of land facilities located or to be located in identified areas having special flood hazards, " Section 2 (b) (4) of the Flood Disaster Protection Act of 1973. In addition to the identification of Special Flood Hazard Areas (SFHAs), the risk zones shown on the FIRMs are the basis for the establishment of premium rates for flood coverage offered through the NFIP. The DFIRM Database presents the flood risk information depicted on the FIRM in a digital format suitable for use in electronic mapping applications. The DFIRM database is a subset of the Digital FIS database that serves to archive the information collected during the FIS. For more information, contact: GIS Manager Information Technology & Innovation (ITI) Montgomery County Planning Department, MNCPPC T: 301-650-5620

After the federal government passed the Clean Water Act in 1972, MNCPPC contracted a series of floodplain studies throughout Montgomery County from the early seventies through the late eighties. These studies used the same rainfall assumptions used today in the FEMA DFIRM floodplain maps. The difference is that the MNCPPC floodplain studies include both an existing conditions analysis but also the ultimate zoning buildout floodplain analysis. This GIS layer represents the ultimate buildout floodplain analysis. As such, this floodplain is generally the most conservative for any area of the County. DPS is in charge of maintaining this layer as it's starting point from which subsequent floodplain amendments are lodged. Various cross sections of this floodplain GIS layer are tagged to a scanned analysis document which can be viewed from the popup. Aside from some of these later floodplain amendments, this original MNCPPC floodplain remains in effect for most of the county's regulatory projects.For more information, contact: GIS Manager Information Technology & Innovation (ITI) Montgomery County Planning Department, MNCPPC T: 301-650-5620

EXERCISE ONLYPurpose and AudienceThis web application is designed to serve as a situational awareness map for flood response (or training for flood response) in Montgomery County, Maryland. The map shows flood hazard areas and includes critical infrastructure (such as police and fire stations, hospitals, and schools). There is also Social Vulnerability Index layer, and live feeds from stream gauges and world traffic. This map is for use by emergency management staff and first responders to maintain situational awareness during a flood event or training.Data SourcesThe live feeds were obtained through Esri's Living Atlas. The flood hazard layer was derived from FEMA's National Flood Hazard Layer. The infrastructure layers were obtained from the Homeland Infrastructure Foundation Level Data (HIFLD) Open Data Portal (Hospitals, Schools, Fire Stations) and the Maryland Open Data Portal (Police Stations).

Montgomery County 100 Year Floodplains as delineated by FEMA and by M-NCPPC

The National Flood Hazard Layer (NFHL) data incorporates all Flood Insurance Rate Map (FIRM) databases published by the Federal Emergency Management Agency (FEMA), and any Letters of Map Revision (LOMRs) that have been issued against those databases since their publication date. It is updated on a monthly basis. The FIRM Database is the digital, geospatial version of the flood hazard information shown on the published paper FIRMs. The FIRM Database depicts flood risk information and supporting data used to develop the risk data. The primary risk classifications used are the 1-percent-annual-chance flood event, the 0.2-percent-annual-chance flood event, and areas of minimal flood risk. The FIRM Database is derived from Flood Insurance Studies (FISs), previously published FIRMs, flood hazard analyses performed in support of the FISs and FIRMs, and new mapping data, where available. The FISs and FIRMs are published by FEMA. The NFHL is available as State or US Territory data sets. Each State or Territory data set consists of all FIRM Databases and corresponding LOMRs available on the publication date of the data set. The specification for the horizontal control of FIRM Databases is consistent with those required for mapping at a scale of 1:12,000. This file is georeferenced to the Earth's surface using the Geographic Coordinate System (GCS) and North American Datum of 1983.

The National Flood Hazard Layer (NFHL) data incorporates all Flood Insurance Rate Map (FIRM) databases published by the Federal Emergency Management Agency (FEMA), and any Letters of Map Revision (LOMRs) that have been issued against those databases since their publication date. It is updated on a monthly basis. The FIRM Database is the digital, geospatial version of the flood hazard information shown on the published paper FIRMs. The FIRM Database depicts flood risk information and supporting data used to develop the risk data. The primary risk classifications used are the 1-percent-annual-chance flood event, the 0.2-percent-annual-chance flood event, and areas of minimal flood risk. The FIRM Database is derived from Flood Insurance Studies (FISs), previously published FIRMs, flood hazard analyses performed in support of the FISs and FIRMs, and new mapping data, where available. The FISs and FIRMs are published by FEMA. The NFHL is available as State or US Territory data sets. Each State or Territory data set consists of all FIRM Databases and corresponding LOMRs available on the publication date of the data set. The specification for the horizontal control of FIRM Databases is consistent with those required for mapping at a scale of 1:12,000. This file is georeferenced to the Earth's surface using the Geographic Coordinate System (GCS) and North American Datum of 1983.

The FIRM is the basis for floodplain management, mitigation, and insurance activities for the National Flood Insurance Program (NFIP). Insurance applications include enforcement of the mandatory purchase requirement of the Flood Disaster Protection Act, which "... requires the purchase of flood insurance by property owners who are being assisted by Federal programs or by Federally supervised, regulated or insured agencies or institutions in the acquisition or improvement of land facilities located or to be located in identified areas having special flood hazards, " Section 2 (b) (4) of the Flood Disaster Protection Act of 1973. In addition to the identification of Special Flood Hazard Areas (SFHAs), the risk zones shown on the FIRMs are the basis for the establishment of premium rates for flood coverage offered through the NFIP. The FIRM Database presents the flood risk information depicted on the FIRM in a digital format suitable for use in electronic mapping applications. The FIRM Database serves to archive the information collected during the Flood Risk Project.

The Georgia Flood MAP Program provides FEMA flood study models for download. Where available, hydraulic models are provided in U.S. Army Corps of Engineers’ HEC-RAS format, which meet all FEMA NFIP guidelines and specifications. Please note, modeling extents may vary from what is shown on FEMA’s regulatory products. It is recommended that users compare downloaded models with the latest effective regulatory products published by FEMA before use. By accepting the download disclaimer, the user agrees that the model is provided as-is for use and analysis.

Map image service contains water related features, including floodzones. Please note that Montgomery County VA is not the original data source for several of these layers but is only sharing for ease of access as a courtesy. For Federally sourced datasets, please visit corresponding Federal Department website. Included layers: Hydrography: Minor Streams, Christiansburg Hydrography (NHD), Blacksburg Hydrography (NHD), Hydrography, Lakes & Ponds, Major WaterbodyFIRM Base Flood Elevations (Federal Emergency Management Agency aka FEMA)Special Flood Hazard Area (FEMA)FIRM Panels (FEMA)NWI Wetlands (Fish & Wildlife Service - National Wetlands Inventory)Flood Map and Elevation CertificatesHUC12 Watersheds (USGS National Watershed Boundary)

DO NOT DELETE. This is a non-editable feature layer used in the Online Permit Application System owned by the Permit Department of Montgomery County.This layer is for the Permit Application form. It contains tax parcel boundaries cross referenced with data from other sources including the following:FEMA F.I.R.M PanelFEMA Flood Hazard ZonesFEMA LOMRMontgomery Central Appraisal District, AbstractMontgomery Central Appraisal District, SubdivisionsMontgomery Central Appraisal District, Tax ParcelsMontgomery County GIS, Commissioner PrecinctsMontgomery County GIS, ETJMontgomery County Elections, Voter PrecinctU. S. Census Bureau, Census TractsU. S. Geological Survey, Watershed Boundary DataU. S. Geological Survey, National Hydrology Data