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GIS Data Clearinghouse Frequently Asked Questions

Where do I go to download the files ?

Note:  The GIS Clearinghouse is available only to Cooperative Data Program members. Non-members may purchase some GIS data at

What projection, coordinate system, and zone does NCTCOG use?

Internally all of our data are stored using North American Datum 83, State Plane Coordinate System, and North Central Texas Zone. However, GIS data can also be downloaded as NAD 27, Latitude/Longitude or UTM.

What data formats are available? 

GIS data can be downloaded into many formats. A brief listing includes: Shapefiles (.shp) AutoCAD Export (.dxf), AutoCAD Drawing (.dwg), Arc/Info Export (.e00), Arc/Info Coverage, MapInfo, and Microstation.

What software does NCTCOG use internally?

We exclusively use products from ESRI. This includes the ArcGIS suite, ArcSDE, and ArcIMS.

How often are NCTCOG's GIS data updated?

Features are updated on a daily basis, roads are updated on a bi-annual (twice a year) basis, city limits are updated on an annual (once a year) basis, zip codes are updated on a biennially (every other year), land use are updated every five years, and Census data are updated every ten years. All other GIS data are updated on an “as needed” basis.

Does the GIS data have a disclaimer?

These data are to be used for graphical representation only. The accuracy is not to be taken/used as data produced for engineering purposes or by a Registered Professional Land Surveyor for the State of Texas. For this level of detail, supervision and certification of the produced data by a Registered Professional Land Surveyor for the State of Texas would have to be performed. NCTCOG and its members assume no responsibility for the accuracy of said data.

Are parcel and other appraisal data available on the GIS Data Clearinghouse? 

No. Each appraisal district exclusively owns and maintains their data, and each has a different set of rules about sharing and distribution. For a list of appraisal district contacts, see

Are digital aerial photos included on the GIS Data Clearinghouse or available through the Cooperative Data Program?

No. Aerial photography and digital elevation contours are available for purchase at

Does NCTCOG sell maps along with the data? 

We do not sell paper maps. We only provide the digital data.

What software do I use to view the GIS data after I download it?

ArcMap, ArcView, ArcExplorer, AutoCAD, Intergraph, Microstation, MapInfo.

Is there any free software I can download that will view the data after I download it?

ESRI provides a product called ArcExplorer which is available for free. NCTCOG does not provide technical support for this product or installation instructions.

Is there metadata available for the downloaded files?

Yes. Metadata for all available files can be viewed by clicking here.

 North Central Texas Council of Governments | 616 Six Flags Drive P.O. Box 5888 Arlington, TX 76005-5888
 Main Operator: (817) 640-3300 | Fax: (817) 640-7806