• Please read our May Aquifer Health assessment. The monthly assessment utilizes the District’s monitoring network to… ,
Important New HTGCD Meeting Date!
now scheduled on 1st Thursday
but check the calendar.

Aquifer Science

HTGCD Dedicated Monitoring Wells Project
HTGCD General

District Recharge Review, January 4, 2021

Model Scenario: 2011-like Drought with Current Production, January 4, 2021

Exempt use Estimate Methodology Report August 21, 2020

Summary of Findings: Upper Onion Creek Dye Trace, Hays County, Texas, Winter 2017

Research paper: Geologic Mapping of the Upper Glen Rose in the Onion Creek Basin

2017/2018 Upper Onion Creek Dye Trace Study Preliminary Report

2014 GMA9 Hutchison Report Comparison of Groundwater Monitoring Data with Groundwater Model Results

Water and Wastewater Facilities Plan for the Portion of Hays County West of the IH-35 Corridor February, 2011

Presentation for the Desired Future Condition Process for Groundwater Management Area 9 – Trinity Aquifer

Hydrogeologic Folio Atlas of the Hill Country Aquifer, Blanco, Hays and Travis Counties, central Texas

Texas AgriLife Research Study shows woody plant encroachment has increased stream flow in the Edwards Plateau

Hays County Regional Water and Wastewater Study, Prepared by HDR Engineering for the Hays County Water Development Board, 1989.

HTGCD Region K

Projected Water Quality Degradation for Bear Creek at Ranch Road 1826 Resulting from Direct Discharge Wastewater Permit Requested by Hays County WCID # 1, April 20, 2006, By Raymond M. Slade, Jr., PH, Certified Professional Hydrologist

Ground-Water Evaluation in and Adjacent to Dripping Springs, Texas, Daniel A. Muller, Texas Water Development Board Report 322, 1990.

Regional Water System Study for the City of Dripping Springs, Prepared by Turner, Collie & Braden for the City of Dripping Springs, 1988.

HTGCD Region L
Evaluation for the Development of a Jacob’s Well Groundwater Management Zone in Hays County, Texas, July 2019

Cypress Creek/Jacob’s Well Hydrogeologic Report – December,2008
Title Page thru Chapter 6
Chapter 7 Text  Figures (A)  Figures (B)
Chapter 8 thru Tables
Appendix 1  Appendix 2  Appendix 3  Appendices 4-5

Hydrogeological characterization of baseflow to Jacob’s Well spring, Hays County, Texas, Sarah C. Davidson, Thesis for Master of Science in Geological Sciences, The University of Texas at Austin, December 2008

Wimberley Regional Wastewater Planning Study, Prepared by Guadalupe-Blanco River Authority and R.J. Brandes Company, 1996.

“Ground-Water Conditions of the Trinity Group Aquifer in Western Hays County” (Wimberley Woodcreek Area), Muller, Daniel A., Wesley McCoy, Texas Water Development Board Report LP-205, 1987.


A Streetcar Named Desired Future Conditions:The New Groundwater Availability For Texas
  Robert E. Mace, Rima Petrossian, Robert Bradley, William F.Mullican, III
  Texas Water Development Board, Austin, Texas 78711-3231
  State Bar of Texas
  7th Annual The Changing Face Of Water Rights In Texas
  May 18-19, 2006
  San Antonio
  Chapter 3.1

Mace, Robert E., William F. Mullican, III, and Shao-Chih (Ted) Way, 2001, Estimating groundwater availability in Texas (PDF) in the proceedings of the 1st annual Texas Rural Water Association and Texas Water Conservation Association Water Law Seminar: Water Allocation in Texas: The Legal Issues.” Austin, Texas, January 25-26, 2001

Mace, Robert E., Ali H. Chowdhury, Roberto Anaya, Shao Chih (Tec) Way, September 2000. Groundwater Availability of the Trinity Aquifer, Hill Country Area, Texas: Numerical Simulations through 2050
Texas Water Development Board Report 53.

Borehole Geophysical Techniques for Determining the Water Quality and Reservoir Parameters of Fresh and Saline Water Aquifers in Texas, TWDB Report 343 – by Hughbert A. Collier, June 1993.

Bluntzer, Robert L., 1992, Evaluation of the Ground-Water Resources of the Paleozoic and Cretaceous Aquifers in the Hill Country of Central Texas. (PDF)
Texas Water Development Board, Report 339.


Geologic framework and hydrogeologic characteristics of the Edwards Aquifer outcrop, Hays County, Texas; John A. Hanson and Ted A. Small; U.S. Geological Survey, Water-Resources Investigations Report 95–4265, in cooperation with the Edwards Underground Water District, 1995.

Edwards-Trinity Aquifer System, Oklahoma, Texas; Text & Figures,  USGS Ground Water Atlas of the United States, HA 730-E  Figures

Engineering Assessment and Environmental Inventory and Issues Report Artifical Recharge Enhancement Onion Creek, Hays County, Texas; Prepared for the BS/EACD by the TWDB, 1992.

Other Sources