Aquifer Storage and Recovery Report: Carrizo-Wilcox Aquifer Characterization for Eastern Gonzales and parts of Caldwell and Guadalupe Counties, Texas

Study Summary:

The goal of this study is to map and characterize the Carrizo-Wilcox Aquifer to a depth of 2,000 feet below ground surface within the study area using existing water well reports, well cuttings from new nearby water supply wells, geophysical well logs, and available aquifer data. This study will support the aquifer storage and recovery (ASR) part of the Guadalupe-Blanco River Authority’s (GBRA) Mid-basin Water Supply Project (MBWSP) and is a recommended water management strategy in the 2017 State Water Plan. This ASR project will be used to meet water supply needs in Caldwell, Comal, Guadalupe, and Hays counties. Injected water will be sourced from the Guadalupe River and stored within the Carrizo Aquifer for later recovery to meet demand.

The objectives of the study are to:

  • collect, analyze, and interpret water well and geophysical well logs;
  • incorporate data from new GBRA water supply wells;
  • interpret the stratigraphic framework, lithology, structure and hydrogeology of the study area;
  • map the net sand distribution in the Carrizo-Wilcox Aquifer;
  • analyze the native groundwater quality of the Carrizo-Wilcox Aquifer including mapping the distribution of total dissolved solids;
  • incorporate newly created information into the publicly available BRACS Database and study GIS datasets;
  • prepare and publish study findings in a peer-reviewed TWDB report.
  • fulfill the Texas Water Code §11.155 mandate to “conduct studies of aquifer storage and recovery projects and aquifer recharge projects identified in the state water plan or by interested persons”.
Study Team Members:
Andrea Croskrey, James Golab, and Daniel Collazo
Study Start Date:
Fall 2020
Study Completion Date:
Winter 2021/2022
This study will develop data and a report that will aid GBRA with the development of their proposed ASR project and will also be publicly available to researchers or other stakeholders interested in developing ASR projects.

Study Details


Study Investigators:

Texas Water Development Board
1700 N. Congress Avenue
Austin, TX 78711

Andrea Croskrey, P.G.

James Golab, Ph.D., P.G.

Daniel Collazo

Engaged Stakeholders:

Guadalupe-Blanco River Authority
933 East Court Street
Seguin, TX 781155

Study Milestones

Event Date
Meeting with GBRA, Microsoft Teams October 9, 2020
Meeting with TCEQ, Microsoft Teams December 16, 2020
Meeting with SAWS, Microsoft Teams February 11, 2021
Update meeting with GBRA, Microsoft Teams and on site April 14, 2021
Public webinar, GotoMeeting May 19, 2022


Public Webinars

Final Report