Williamson County makes a variety of GIS data available to the public. The table below is our online catalog, and most of data are available for immediate download. Other data must be requested via our request form, and still others are linked from other agencies that provide data for Williamson County.

For more information about a data set, please click the metadata link under the data column. If you have questions or need additional information, please feel free to contact us.

All of the data provided by Williamson County will be in ESRI Shapefile format. The files will be in a zipped folder (.ZIP file extension) to conserve bandwidth. Information is provided below on the file formats used and software programs that may be used to access this data.

Williamson County GIS Data Catalog

DATA	PREVIEW	POSTED	LINK
Orthoimagery Description: 2009 6 in resolution Quarter Quadrangle imagery from CAPCOG. More Information: Metadata Data Type: Polygon		01/10/2011	Link
Addresses Description: Addressed structures and property More Information: Metadata Data Type: Point		01/03/2012
Alcohol Rights Boundaries (Wet/Dry) Description: Alcohol-related rights areas More Information: Metadata Data Type: Polygon		11/16/2010	Contact
Aquifers Description: Major Aquifer zones More Information: Metadata Data Type: Polygon		01/10/2011
Census 2000 Block Groups Description: US Census 2000 Block Group areas More Information: Metadata Data Type: Polygon		01/10/2011
Census 2010 Block Groups Description: US Census 2010 Block Group Area More Information: Metadata Data Type: Polygon		08/02/2011
Census 2000 Blocks Description: US Census 2000 Block areas More Information: Metadata Data Type: Polygon		01/10/2011
Census 2010 Blocks Description: US Census 2010 Block areas More Information: Metadata Data Type: Polygon		08/03/2011
Census 2000 Tracts Description: US Census 2000 Tract areas More Information: Metadata Data Type: Polygon		01/10/2011
Census 2010 Tracts Description: US Census 2010 Tract areas More Information:Metadata Data Type: Polygon		08/04/2011
City Limits Description: City boundary polygons for incorporated Cities More Information: Metadata Data Type: Polygon		01/03/2012
County Boundary Description: County area More Information: Metadata Data Type: Polygon		01/10/2011
County Office Locations Description: County office locations More Information: Metadata Data Type: Point		01/10/2011
County Owned Properties Description: County owned properties More Information: Metadata Data Type: Polygon		01/10/2011	Contact
Emergency Services Districts (ESDs) Description: Boundaries of Emergency Services Districts, which are taxing entities that contract for fire services More Information: Metadata Data Type: Polygon		04/05/2011
FEMA Flood Hazard Areas Description: FEMA Floodplain and flood zones for all of Williamson County. More Information: Metadata Data Type: Polygon		03/24/2009
Historical Markers Description: Location of historical markers More Information: Metadata Data Type: Point		01/10/2011	Contact
Lakes Description:Major lakes and ponds More Information: Metadata Data Type: Polygon		01/10/2011
LiDAR Elevation Data Description: Elevation data in 1.4 Meter LAS files More Information: Metadata Data Type: LAS		01/10/2011	Contact
MUD Boundaries Description: Municipal Utility District areas More Information: Metadata Data Type: Polygon		01/17/2012
Parks and Open Spaces Description: County and city parks and open spaces More Information: Metadata Data Type: Polygon		01/10/2011
Polling Place Locations Description: Polling locations for the the current (or next) election More Information: Metadata Data Type: Point			Link
Precincts Description: JP, Commissioner, Constable Precincts More Information: Metadata Data Type: Polygon		01/10/2011
Rivers and Streams Description: Major rivers and streams More Information: Metadata Data Type: Line		01/10/2011
Roads Description: Road centerlines for all public roads More Information: Metadata Data Type: Line		01/03/2012
School District Boundaries Description: School Districts inside the County More Information: Metadata Data Type: Polygon		01/10/2011
Soil Classifications Description: Generalized soil types More Information: Metadata Data Type: Polygon		01/10/2011
Tile Boundaries for LiDAR Description: Tile boundaries for the 2006 LiDAR elevation data. Can be used to locate tiles for a data request. Data Type: Polygon		01/10/2011	Contact
Trail Locations Description: Recreational trail locations in the County represented as a line feature with names. More Information: Metadata Data Type: Line		01/10/2011
Vegetation Classifications Description: Generalized natural vegetation classifications. More Information: Metadata Data Type: Polygon		01/10/2011
Parcels Description: Parcels are NOT maintained by Williamson County. They are maintained by the Williamson Central Appraisal District (WCAD), a seperate entity from the County. Please visit their site to view an interactive parcel map or to request data.			Link

Shapefile Information:
Description of the File format: Wikipedia
Technical Documentation of Shapefile: ESRI White Paper (PDF link)

ZIP File Information:
The ZIP format is a compressed version of files and data in a single "package" format that makes it easy to transfer. Many software packages can open ZIP format files, including many operating systems. There are many freely available programs, so we have selected a good one at random: ALZip from ALTools (Windows) (Freeware).

Williamson County GIS data can be used natively or imported into a variety of commercial programs. To name the most popular:

• ArcGIS
• AutoCAD
• Microstation
• GeoMedia
• MapInfo

In addition to the commercial software, there are some free resources for interacting with our GIS data. At this time Williamson County cannot provide support or assistance for using our data with these products, but there are a number of good guides and tutorials available on the internet.

• ArcExplorer
• Map Window
• Shape Viewer
• GIS Shapefile Viewer

The maps and data on this site are for general planning purposes only. The underlying basemap conforms to National Map Accuracy Standards in unobstructed areas. Williamson County makes no warranty, representation or guarantee as to the content, sequence, accuracy, timeliness or completeness of any of the database information or spatial locations depicted. Furthermore, all warranties on merchantability and fitness for a particular purpose are hereby disclaimed. In no event shall Williamson County be liable to the recipient or any other party for damages of any type, including but not limited to incidental, consequential or exemplary damages arising out of the use or inability to use these materials.