This dataset was created by the Transportation Planning and Programming (TPP) Division of the Texas Department of Transportation (TxDOT) for planning and asset inventory purposes, as well as for visualization and general mapping. County boundaries were digitized by TxDOT using USGS quad maps, and converted to line features using the Feature to Line tool. This dataset depicts a generalized coastline.Update Frequency: As NeededSource: Texas General Land OfficeSecurity Level: PublicOwned by TxDOT: FalseRelated LinksData Dictionary PDF [Generated 2025/03/14]

This site provides access to download an ArcGIS geodatabase or shapefiles for the 2017 Texas Address Database, compiled by the Center for Water and the Environment (CWE) at the University of Texas at Austin, with guidance and funding from the Texas Division of Emergency Management (TDEM). These addresses are used by TDEM to help anticipate potential impacts of serious weather and flooding events statewide. This is part of the Texas Water Model (TWM), a project to adapt the NOAA National Water Model [1] for use in Texas public safety. This database was compiled over the period from June 2016 to December 2017. A number of gaps remain (towns and cities missing address points), see Address Database Gaps spreadsheet below [4]. Additional datasets include administrative boundaries for Texas counties (including Federal and State disaster-declarations), Councils of Government, and Texas Dept of Public Safety Regions. An Esri ArcGIS Story Map [5] web app provides an interactive map-based portal to explore and access these data layers for download.

The address points in this database include their "height above nearest drainage" (HAND) as attributes in meters and feet. HAND is an elevation model developed through processing by the TauDEM method [2], built on USGS National Elevation Data (NED) with 10m horizontal resolution. The HAND elevation data and 10m NED for the continental United States are available for download from the Texas Advanced Computational Center (TACC) [3].

The complete statewide dataset contains about 9.28 million address points representing a population of about 28 million. The total file size is about 5GB in shapefile format. For better download performance, the shapefile version of this data is divided into 5 regions, based on groupings of major watersheds identified by their hydrologic unit codes (HUC). These are zipped by region, with no zipfile greater than 120mb: - North Tx: HUC1108-1114 (0.52 million address points) - DFW-East Tx: HUC1201-1203 (3.06 million address points) - Houston-SE Tx: HUC1204 (1.84 million address points) - Central Tx: HUC1205-1210 (2.96 million address points) - Rio Grande-SW Tx: HUC2111-1309 (2.96 million address points)

Additional state and county boundaries are included (Louisiana, Mississippi, Arkansas), as well as disaster-declaration status.

Compilation notes: The Texas Commission for State Emergency Communications (CSEC) provided the first 3 million address points received, in a single batch representing 213 of Texas' 254 counties. The remaining 41 counties were primarily urban areas comprising about 6.28 million addresses (totaling about 9.28 million addresses statewide). We reached the GIS data providers for these areas (see Contributors list below) through these emergency communications networks: Texas 9-1-1 Alliance, the Texas Emergency GIS Response Team (EGRT), and the Texas GIS 9-1-1 User Group. The address data was typically organized in groupings of counties called Councils of Governments (COG) or Regional Planning Commissions (RPC) or Development Councils (DC). Every county in Texas belongs to a COG, RPC or DC. We reconciled all counties' addresses to a common, very simple schema, and merged into a single geodatabase.

November 2023 updates: In 2019, TNRIS took over maintenance of the Texas Address Database, which is now a StratMap program updated annually [6]. In 2023, TNRIS also changed its name to the Texas Geographic Information Office (TxGIO). The datasets available for download below are not being updated, but are current as of the time of Hurricane Harvey.

References: [1] NOAA National Water Model [https://water.noaa.gov/map] [2] TauDEM Downloads [https://hydrology.usu.edu/taudem/taudem5/downloads.html] [3] NFIE Continental Flood Inundation Mapping - Data Repository [https://web.corral.tacc.utexas.edu/nfiedata/] [4] Address Database Gaps, Dec 2017 (download spreadsheet below) [5] Texas Address and Base Layers Story Map [https://www.hydroshare.org/resource/6d5c7dbe0762413fbe6d7a39e4ba1986/] [6] TNRIS/TxGIO StratMap Address Points data downloads [https://tnris.org/stratmap/address-points/]

This layer is a component of IdentifyParcels.

The Gonzales County Underground Water Conservation District (UWCD) Public Map includes a variety of layers containing well, aquifer, water quality, water level, reporting, and boundary information. Moreover, this map provides interactive tools such as the ability to conduct virtual aquifer bores within the district. Contact Email: admin@gcuwcd.org

This collection contains Texas statewide map data often used as base layers for hydrologic and geographic analysis, organized by these categories: - Addresses and Boundaries (Texas address points, counties, Councils of Government boundaries, Texas Dept of Public Safety districts and regions) - Hydrology (streams, gages, dams, catchments, watersheds) - Transportation (Texas roads, railways, bridges, low water crossings)

These data layers generally date to 2015-2016.

The Texas Address and Base Layers Story Map referenced here [1] is an interactive web app supported by Esri ArcGIS Online, that provides visualization and access to specific data layers for Texas only.

References [1] Texas Address and Base Layers Story Map [https://www.hydroshare.org/resource/6d5c7dbe0762413fbe6d7a39e4ba1986/]

The Texas Department of Transportation (TxDOT) maintains a spatial dataset of roadway polylines for planning and asset inventory purposes, as well as for visualization and general mapping. This dataset covers the state of Texas and includes on-system routes (those that TxDOT maintains), such as interstate highways, U.S. highways, state highways, and farm and ranch roads, as well as off-system routes, such as county roads and local streets. Route segments in this version of TxDOT Roadways are broken by functional classification. For an unsegmented version of TxDOT Roadways, see TxDOT Roadways Unsegmented.

This data contains measures. Measures are stored as M-values within each vertex along the line, in the same way that some datasets store z-values for the elevation, except that measures store the distance from the origin, or DFO, along the line. M-enabled networks serve as frameworks for locating roadway assets along the network using linear referencing. This data set must be downloaded as a file geodatabase in order to keep M-Values intact. If downloaded as a shapefile or added to a map from a connection to ArcGIS online, measures will not be applied to the line.

Update Frequency: Monthly

Source: Geospatial Roadway Inventory Database (GRID)

Security Level: Public

This collection contains map data often used as base layers for hydrologic and geographic analysis, organized by these categories: - Addresses and Boundaries (Texas address points, counties, Councils of Government boundaries, Texas Dept of Public Safety districts and regions) - Hydrology (streams, gages, dams, catchments, watersheds) - Transportation (Texas roads, railways, bridges, low water crossings)

The Addresses, Transportation and Dams datasets are for Texas only, but the remaining Hydrology data covers an area of 39 HUC6 basins around the Harvey zone across southeast Texas, Louisiana, Mississippi and Arkansas.

These data layers generally date to 2015-2016, so could be considered reasonably representative of the base layers at the time of Hurricane Harvey.

The Texas Address and Base Layers Story Map referenced here [1] is an interactive web app supported by Esri ArcGIS Online, that provides visualization and access to specific data layers for Texas only.

One other base layer is the Social Vulnerability Index (SVI) developed by the U.S. Centers for Disease Control (CDC). This is used by the emergency response community to anticipate areas where social support systems are weaker, and residents may be more likely to need help.

References [1] Texas Address and Base Layers Story Map [https://www.hydroshare.org/resource/6d5c7dbe0762413fbe6d7a39e4ba1986/]

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

City of Elgin Zoning overlay for both Travis and Bastrop County Elgin city limits.

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.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.

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.

Max Speed limit values in miles per hour. This data is an extract from the Geospatial Roadway Inventory Databse (GRID), which is TxDOT's system for managing roadway assets in Texas.Note: Extracts from GRID are made on a regular basis and reflect the state of the data at that moment. Assets on routes that are in the process of being edited may be affected.Update Frequency: 1 MonthsSource: Geospatial Roadway Inventory Database (GRID)Security Level: PublicOwned by TxDOT: TrueRelated LinksData Dictionary PDF [Generated 2025/04/24]