Edwards BFZ Aquifer (San Antonio segment)Groundwater Availability Model (GAM)

The U.S. Geological Survey in cooperation with the U.S. Department of Defense and the Edwards Aquifer Authority (EAA) have developed a GAM for the San Antonio segment of the Edwards Aquifer. However, the Texas Water Development Board will continue to maintain GWSIM as a model with an alternative hydraulic conductivity distribution and as an easier-to-use screening tool.

Model Report

"Conceptualization and Simulation of the Edwards Aquifer, San Antonio Region, Texas." | USGS SIR 2004-5277.

USGS SIR 2004-5277 Plates 1 through 3.

USGS SIR 2004-5277 Plates 4 through 7.

"Model Refinement and Applications for the Edwards (Balcones Fault Zone) Aquifer in the San Antonio Region, Texas."

"Summary of a GWSIM-IV Run Simulating the Effects of the Edwards Aquifer Authority Critical Period Management Plan for the Regional Water Planning Process."

Model Files

Please contact David Thorkildsen (512-936-0871) for a copy of model files. The model files are available in an electronic format with a small processing fee per CD/DVD.

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 centroid based approach. The model grid is available in ESRI® shapefile format and comma-delimited text file.

Download model grid.

Aquifer Data

Aquifer data is only available as a package for the entire model area and requires GIS software for processing. Due to the size of raw/source data files for this model, this information has not been posted on the web. The raw/source data may be requested on CD(s) in an electronic format with a processing fee by contacting David Thorkildsen (512-936-0871).

Stakeholder Advisory Forums (SAF)

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

Other Resources

Please see the Edwards (Balcones Fault Zone) Aquifer page for other reports and publications.

For model runs see the GMA 10 page.