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.

This is the Subdivision Interactive Plat Viewer for the City of Rockwall, TX. Use for general reference only.Alternate Plat Viewer Page

Quick Start This is a collection of flood datasets to support hydrologic research for Hurricane Harvey, August-September 2017. The best way to start exploring this collection is by opening the Hurricane Harvey 2017 Story Map [2]. It has separate sections for the different content categories, and links to the relevant HydroShare resources within this collection.

More Details This is the root collection resource for management of hydrologic and related data collected during Hurricane Harvey on the Texas-Louisiana Gulf coast. This collection holds numerous composite resources comprising streamflow forecasts, inundation polygons and depth grids, flooding impacts, elevation grids, high water marks, and numerous other related information sources. Texas address points are included to support estimating storm and flood impacts in terms of structures within an affected area.

The data providers for this collection are the Texas Division of Emergency Management, NOAA National Weather Service, NOAA National Hurricane Center, NOAA National Water Center, FEMA, 9-1-1 emergency communications agencies, and many others. Esri and Kisters also provided invaluable tools, data and geoprocessing services to support the initial data production, and these are included or referenced.

User-contributed resources from 2017 US Hurricanes may also be shared with The CUAHSI 2017 Hurricane Data Community group [1] to make them accessible to interested researchers, Anyone may join this group.

An ArcGIS Story Map [2] has been created which provides example data views and interactive access to this collection.

This collection has been produced by work on a US National Science Foundation RAPID Award "Archiving and Enabling Community Access to Data from Recent US Hurricanes" [3].

References [1] CUAHSI 2017 Hurricane Data Community group [https://www.hydroshare.org/group/41] [2] Hurricane Harvey 2017 Archive Story Map [https://arcg.is/1rWLzL0] [3] NSF RAPID Grant [https://nsf.gov/awardsearch/showAward?AWD_ID=1761673]