Igneous Aquifer | Texas Water Development Board

Igneous Aquiferinteractive map | cross-section

Aquifer Facts

  • Aquifer type: unconfined
  • Area of aquifer: 6,075 square miles
  • Proportion of aquifer with groundwater conservation districts: 100 percent
  • Number of counties containing the aquifer: 6

Summary

The Igneous Aquifer is a minor aquifer located in Far West Texas. The aquifer consists of volcanic rocks made up of a complex series of welded pyroclastic rock, lava, and volcaniclastic sediments and includes more than 40 different named units as much as 6,000 feet thick. Freshwater saturated thickness averages about 1,800 feet. The best water bearing zones are found in igneous rocks with primary porosity and permeability, such as vesicular basalts, interflow zones in lava successions, sandstone, conglomerate, and breccia. Faulting and fracturing enhance aquifer productivity in less permeable rock units.

AWater in the Igneous Aquifer is fresh and contains less than 1,000 milligrams per liter of total dissolved solids. Groundwater from some wells contains elevated levels of silica and fluoride, as a result of weathering of the igneous rock that makes up the aquifer. Groundwater in a few wells exceeds maximum contaminant levels for arsenic, fluoride, and gross alpha radiation.

Water is primarily used to meet municipal needs for the cities of Alpine, Fort Davis, and Marfa, as well as some agricultural needs.

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
R-356 12/1/2001 TWDB numbered report Aquifers of West Texas
R-016 2/1/1966 TWDB numbered report Water-Level Data from Observation Wells in Culberson, Jeff Davis, Presidio, and Brewster Counties, Texas
GT10-028 7/29/2010 GAM task Predictive simulations for the Igneous and West Texas Bolsons aquifers in Groundwater Management Area 4
GT10-026 6/24/2010 GAM task Predictive simulation for the Igneous and West Texas Bolsons aquifers in Groundwater Management Area 4
GR10-003 6/29/2010 GAM run Predictive simulations for the Igneous and West Texas Bolsons aquifers in Groundwater Management Area 4
GR09-025 1/11/2011 GAM run Predictive simulation for the Igneous and West Texas Bolsons aquifers in Groundwater Management Area 4
GR08-088_MP 3/17/2009 GAM run - Management Plan Management plan information for Presidio County UWCD
GR08-029_MP 5/28/2008 GAM run - Management Plan Management plan information for Jeff Davis County UWCD
GR08-024 12/19/2008 GAM run Predictive simulations for the Igneous and West Texas Bolsons aquifers in Groundwater Management Area 4
GR07-008_MP 4/26/2007 GAM run - Management Plan Management plan information for Brewster County GCD
GR06-032 5/2/2007 GAM run Predictive simulation for the Igneous and West Texas Bolsons aquifers in Groundwater Management Area 4
GR06-017 7/18/2006 GAM run Predictive simulation for the Igneous and West Texas Bolsons aquifers in Groundwater Management Area 4
GR06-004 3/8/2006 GAM run Predictive simulation for the Igneous and West Texas Bolsons aquifers in Jeff Davis and Presidio countie
GR06-002_MP 3/1/2006 GAM run - Management Plan Management plan information for Culberson County GCD
GR05-040 2/7/2006 GAM run Predictive simulation for the Igneous and West Texas Bolsons aquifers in Jeff Davis and Presidio counties
GR11-018_MP 1/23/2012 GAM run - Management Plan Culberson County GCD Management Plan
GR12-023_MP 8/10/2012 GAM run - Management Plan Management plan data for Jeff Davis County UWCD
R-380 7/1/2011 TWDB numbered report Aquifers of Texas
GR12-026_MP 3/21/2013 GAM run - Management Plan Management plan data for Presidio County UWCD
GT13-027_TERS 9/19/2013 GAM task - Total Estimated Recoverable Storage Total Estimated Recoverable Storage for aquifers in Groundwater Management Area 3
GT13-030_TERS 10/2/2013 GAM task - Total Estimated Recoverable Storage Total Estimated Recoverable Storage for aquifers in Groundwater Management Area 7
GR13-020_MP 10/7/2013 GAM run - Management Plan Management Plan data for Brewster County GCD
GT13-028_TERS 1/15/2014 GAM task - Total Estimated Recoverable Storage Total Estimated Recoverable Storage for aquifers in Groundwater Management Area 4
GR19-008_MP 2/27/2019 GAM run - Management Plan Management plan information for Brewster County GCD
GR19-007_MP 3/18/2019 GAM run - Management Plan Management plan information for Presidio County UWCD
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