Hickory Aquiferinteractive map | cross-section

Aquifer Facts

  • Aquifer type: confined and unconfined
  • Area of outcrop: 272 square miles
  • Area of subsurface: 8,317 square miles
  • Proportion of aquifer with groundwater conservation districts: 85 percent
  • Number of counties containing the aquifer: 19

Summary

The Hickory Aquifer is a minor aquifer in the central part of the state that consists of the water-bearing parts of the Hickory Sandstone Member. The Hickory Member is a mixture of terrestrial and marine sandstones, siltstones, and mudstones. The Hickory Aquifer reaches a maximum thickness of 480 feet, and freshwater saturated thickness averages about 350 feet.

Groundwater is mostly fresh with less than 1,000 milligrams per liter of total dissolved solids. Excess iron in the upper portion of the aquifer may result in poor-tasting water and may exceed drinking water standards. Additionally, naturally occurring radioactivity may exceed the state’s primary drinking standards. Radionuclides are derived from the Precambrian granite rocks in the Llano Uplift.

The groundwater is used for irrigation throughout its extent and for municipal supply in the cities of Brady, Mason, and Fredericksburg.

Reports

ID Date Type Description
Texas Aquifers Study 12/31/2016 Legislative Report Texas Aquifers Study: Groundwater Quantity, Quality, Flow, and Contributions to Surface Water
B-6004 8/1/1960 Groundwater bulletin Geology and Ground-Water Resources of Hays County, Texas
R-057 9/1/1967 TWDB numbered report Occurrence and Quality of Ground Water in Coleman County, Texas
R-235 7/1/1979 TWDB numbered report Occurrence, Availability, and Chemical Quality of Ground Water in the Edwards Plateau Region of Texas
R-174 7/1/1973 TWDB numbered report Ground-Water Resources of Blanco County, Texas
R-360 2/9/2004 TWDB numbered report Conference Proceedings: Aquifers of the Edwards Plateau
R-346 3/1/1996 TWDB numbered report The Paleozoic and Related Aquifers of Central Texas
R-339 8/1/1992 TWDB numbered report Evaluation of Ground-Water Resources of the Paleozoic and Cretaceous Aquifers in the Hill Country of Central Texas
B-6519 8/1/1965 Groundwater bulletin Ground-Water Conditions in Menard County, Texas
B-6017 2/1/1961 Groundwater bulletin Ground-Water Geology of the Hickory Sandstone Member of the Riley Formation, McCulloch County, Texas
AA08-07 8/31/2010 Aquifer assessment Desired future condition scenarios for the Hickory Aquifer in Groundwater Management Area 7
AA10-05 9/10/2010 Aquifer assessment Desired future condition scenarios for the Hickory Aquifer in Groundwater Management Area 7
GMA8_DFC_05 4/27/2011 DFC submission Desired future conditions for the Blossom, Brazos River Alluvium, Edwards (Balcones Fault Zone), Ellenburger-San Saba, Hickory, Marble Falls, Nacatoch, Trinity, and Woodbine aquifers
CR-1004831116 7/11/2012 Contract report Aquifer Test and Related Well Information from Public Water Supply Wells in Groundwater Management Area 8
R-380 7/1/2011 TWDB numbered report Aquifers of Texas
GT13-030_TERS 10/2/2013 GAM task - Total Estimated Recoverable Storage Total Estimated Recoverable Storage for aquifers in Groundwater Management Area 7
GT13-032_TERS 10/2/2013 GAM task - Total Estimated Recoverable Storage Total Estimated Recoverable Storage for aquifers in Groundwater Management Area 9
GT13-031_TERS 1/15/2014 GAM task - Total Estimated Recoverable Storage Total Estimated Recoverable Storage for aquifers in Groundwater Management Area 8
GR16-006_MP 6/21/2016 GAM run - Management Plan Management plan information for Central Texas GCD
GR16-019_MP 9/17/2016 GAM run - Management Plan Management plan information for Headwaters GCD
GR17-028_MP 3/27/2017 GAM run - Management Plan Management plan information for Menard County UWD
GR17-005_MP 5/26/2017 GAM run - Management Plan Management plan information for Lipan-Kickapoo Water Conservation District
GR17-009_MP 1/30/2018 GAM run - Management Plan Management plan information for Hill Country UWCD
GR13-010_MP 6/4/2018 GAM run - Management Plan Management plan information for Hickory UWCD no.1
GR18-007_MP 7/13/2018 GAM run - Management Plan Management plan information for Hickory UWCD #1
GR18-015_MP 9/28/2018 GAM run - Management Plan Management plan information for Kimble County GCD
GR19-011_MP 2/27/2019 GAM run - Management Plan Management plan information for Cow Creek GCD
GR19-005_MP 3/15/2019 GAM run - Management Plan Management plan information for Saratoga UWCD
GR19-027_MP 12/13/2019 GAM run - Management Plan Management plan information for Southwestern Travis County GCD
GR19-026_MP 1/9/2020 GAM run - Management Plan Management plan information for Hays Trinity GCD
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