Hydrography Data and Map-Based Data Viewers

Major River and Coastal Basins of Texas

Texas river and coastal basins are numbered as part of a classification system TCEQ uses to support management of surface water resources. Segments (portions or reaches) of a basin are assigned numbers that begin with the basin number and add two additional numbers that identify a specific area of a water body: for example, Segment 0101 of the Canadian River. 

Download a map of the 23 major Texas River Basins.

Data Viewers

Viewers use a map-based user interface to give access to data. These pages are sometimes slow to load.

• Surface Water Segment Viewer
  Use this viewer to locate water bodies in Texas
• Surface Water Quality Data Viewer 
  Use this viewer to locate monitoring stations and download water quality data
• Edwards Aquifer Data 
  Recharge, contributing, and transition zones; boundaries 
• Other Viewers

GIS Data Sets

Data layers for use in ArcGIS. Includes data such as stream, lake, and bay segments; permitted wastewater outfalls; regulatory boundaries; and land use. Some file sizes are large and therefore may be slow to download or may "timeout" before download is complete.

• Texas Ecoregions - Maps and Data on the EPA website
• TCEQ Water Data
  Stream segments, assessment units, monitoring stations, and more

For More Information

Contact us at 512-239-6682 or email tmdl@tceq.texas.gov and mention GIS data in the subject line.