Central portion of the Carrizo-Wilcox AquiferGroundwater Availability Model (GAM)This map shows the extent and location of the central portion of the Carrizo-Wilcox Aquifer GAM.

In 2015 the Texas Water Development Board (TWDB) contracted with INTERA Inc. (teamed with RW Harden and Associates, GSI Environmental Inc., Alan Dutton, Tom Ewing, and John Doherty) to evaluate faults in the central portion of the Carrizo-Wilcox Aquifer and improve their representation in an updated groundwater availability model for the central portion of the Carrizo Wilcox, Queen City, and Sparta Aquifers. The project was completed at the end of 2018.

Previously, the TWDB contracted with the Bureau of Economic Geology (which teamed with R.W. Harden and Associates, Inc., and HDR Engineering, Inc.) to develop a groundwater availability model of the central part of the Carrizo-Wilcox Aquifer in Texas. The final technical report and model were delivered in 2003 (see below).

This groundwater availability model supersedes the Carrizo-Wilcox, Queen City, Sparta Aquifers Groundwater Availability Model, but only in its central portion.

Final Technical Report (2003)

Groundwater Availability Model For the Central Part of the Carrizo-Wilcox Aquifer in Texas

Final Numerical Model Report (2018)

Final Report, Volume I: Groundwater Availability Model for the Central Portion of the Sparta, Queen City, and Carrizo-Wilcox Aquifers

Final Report, Volume II: Groundwater Availability Model for the Central Portion of the Sparta, Queen City, and Carrizo-Wilcox Aquifers

Memorandum: Predictive Simulations Comparison Analysis Report

Updated Final Numerical Model Report (2020)

In a meeting on July 24, 2020, Groundwater Management Area 12 members voted to have their consultants modify the Groundwater Availability Model for the central portion of the Carrizo-Wilcox, Queen City and Sparta aquifers.The purpose of the modification is to more accurately represent the transmissive properties of the Simsboro Aquifer in the vicinity of the Vista Ridge well field. The modification to the model had a relatively minor change in the statistics of the model calibration from 1930 to 2020. This modified model is proposed to replace the existing groundwater availability model for the central portion of Carrizo-Wilcox, Queen City and Sparta aquifers.The updates to the model are documented in the following summary report:

GMA 12 Update to The Groundwater Availability Model for the Central Portion of the Sparta, Queen City, and Carrizo-Wilcox Aquifers

The model files and supporting geodatabase are available for download at the links below:

MODFLOW files (size: 2.1 GB)

Groundwater Vistas files (size: 1 GB)

Geodatabase (size: 2.3 GB)

These files are being posted for a thirty-day period for stakeholder review. Please provide comments to Larry French or Cindy Ridgeway by November 9, 2020.

Model Grid

Model grid cells are geographically assigned to counties, groundwater conservation districts, river basins, groundwater management areas, and regional water planning areas within the model study area using a node-based approach. The model grid is available in ESRI® shapefile format and comma-delimited text file.

Download model grid

Stakeholder Advisory Forums (SAF)

Send us an email if you would like to receive SAF notifications.

ID Date Location
SAF 2 04/27/2017 Milano, Texas
SAF 1 11/20/2015 Milano, Texas

Other Resources

Please see the Carrizo-Wilcox, Sparta, and Queen City aquifer pages for other reports and publications.

For model runs see the GMA 12 page.

Top