Edwards-Trinity (Plateau) Aquiferinteractive map | cross-section
Aquifer Facts
- Aquifer type: mostly unconfined with small confined areas
- Area of outcrop: 32,373 square miles
- Area of subsurface: 3,051 square miles
- Proportion of aquifer with groundwater conservation districts: 82 percent
- Number of counties containing the aquifer: 41
Summary
The Edwards-Trinity (Plateau) Aquifer is a major aquifer extending across much of the southwestern part of the state. The water-bearing units are composed predominantly of limestone and dolomite of the Edwards Group and sands of the Trinity Group. The saturated thickness of this aquifer system increases from less than 100 feet in the north to greater than 800 feet down-dip to the south. Freshwater saturated thickness averages 433 feet.
Springs occur along the margins of the aquifer where the water table intersects the ground surface. San Felipe Springs is the largest exposed spring along the southern margin. Springs also discharge groundwater along the eastern flanks of the Trans-Pecos Mountains; the lower Pecos River canyons in Del Rio are the largest of these springs. As water levels have declined in the western portion of the aquifer due to increased irrigation pumping, springflows in those areas have also declined. In addition, many small springs that once flowed throughout the plateau have ceased flowing.
The water in the Edwards-Trinity (Plateau) Aquifer is generally a hard, calcium bicarbonate type and typically has total dissolved solids concentrations ranging from 400 to 1,000 milligrams per liter. Water quality in the unconfined portion of the aquifer is generally fresh, with only small, localized areas of slightly saline groundwater. Water typically increases in salinity to the west within the Trinity Group and in the confined portion of the aquifer where the groundwater is generally slightly to moderately saline.
More than two-thirds of groundwater pumped from this aquifer is used for irrigation, with the remainder used for municipal and livestock supplies. Water levels have remained relatively stable because recharge has generally kept pace with the relatively low amounts of pumping over the extent of the aquifer.
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 |
| HA-03 | 1/1/1995 | Hydrologic atlas | Water Quality in the Edwards-Trinity (Plateau) Aquifer, Edwards Plateau and Trans-Pecos, Texas |
| R-317 | 1/1/1990 | TWDB numbered report | Evaluation of Ground-Water Resources in Parts of Loving, Pecos, Reeves, Ward and Winkler Counties, Texas |
| R-255 | 9/1/1980 | TWDB numbered report | Occurrence and Quality of Ground Water in the Edwards-Trinity (Plateau) Aquifer in the Trans-Pecos Region of Texas |
| R-356 | 12/1/2001 | TWDB numbered report | Aquifers of West Texas |
| LP-214 | 2/1/1995 | Limited publication | Evaluation of Ground-Water Quality in Texas Counties Bordering the Rio Grande |
| AA08-06 | 6/17/2009 | Aquifer assessment | Desired future condition scenarios for the Edwards-Trinity (Plateau) Aquifer - Glasscock, Reagan, Upton and Midland counties |
| B-6212 | 7/1/1962 | Groundwater bulletin | Geology and Ground-Water Resources of Uvalde County, Texas |
| B-6216 | 12/1/1962 | Groundwater bulletin | Geology and Ground-Water Resources of Kinney County, Texas |
| B-6210 | 5/1/1962 | Groundwater bulletin | Ground-Water Geology of Bandera County, Texas |
| R-047 | 5/1/1967 | TWDB numbered report | Occurrence and Quality of Ground Water in Crockett County, Texas |
| R-050 | 6/1/1967 | TWDB numbered report | Ground-Water Resources of Mitchell and Western Nolan Counties, 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-296 | 11/1/1986 | TWDB numbered report | Carbonate Geology and Hydrology of the Edwards Aquifer in the San Antonio Area, Texas |
| R-102 | 11/1/1969 | TWDB numbered report | Ground-Water Resources of Kerr County, Texas |
| R-029 | 9/1/1966 | TWDB numbered report | Base-Flow Studies, Upper Guadalupe River Basin, Texas, Quality and Quantity |
| R-353 | 9/1/2000 | TWDB numbered report | Groundwater Availability of the Trinity Aquifer, Hill Country Area, Texas: Numerical Simulations through 2050 |
| R-360 | 2/9/2004 | TWDB numbered report | Conference Proceedings: Aquifers of the Edwards Plateau |
| R-224 | 10/1/1978 | TWDB numbered report | Occurrence, Quantity, and Quality of Ground Water in Taylor County, Texas |
| 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 |
| R-330 | 7/1/1991 | TWDB numbered report | Evaluation of Ground-Water Resources in the Southern High Plains of Texas |
| B-6519 | 8/1/1965 | Groundwater bulletin | Ground-Water Conditions in Menard County, Texas |
| B-6208 | 4/1/1962 | Groundwater bulletin | Ground-Water Geology of Edwards County, Texas |
| R-078 | 5/1/1968 | TWDB numbered report | Ground-Water Resources of Upton County, Texas |
| R-132 | 8/1/1971 | TWDB numbered report | Water Well and Ground-Water Chemical Analysis Data, Schleicher County, Texas |
| R-145 | 4/1/1972 | TWDB numbered report | Water Wells and Ground-Water Chemical Analysis Data, Reagan County, Texas |
| R-146 | 4/1/1972 | TWDB numbered report | Water Well and Ground-Water Chemical Analysis Data, Irion County, Texas |
| R-148 | 5/1/1972 | TWDB numbered report | Water Well and Ground-Water Chemical Analysis Data, Sterling County, Texas |
| R-166 | 3/1/1973 | TWDB numbered report | Ground-Water Resources of Coke County, Texas |
| R-172 | 6/1/1973 | TWDB numbered report | Ground-Water Resources of Val Verde County, Texas |
| GR11-013_MP | 10/4/2011 | GAM run - Management Plan | Management plan information for Menard County UWCD |
| AA06-01 | 6/10/2008 | Aquifer assessment | Water-level decline scenarios for the Capitan Reef Complex, Marathon, Rustler, Presidio-Redford Bolson, Edwards-Trinity (Plateau), and Diablo Plateau aquifers in Groundwater Management Area 4 |
| AA09-12 | 8/31/2010 | Aquifer assessment | Desired future condition scenarios for the Edwards-Trinity (Plateau) Aquifer in Groundwater Management Area 4 |
| GR11-003_MP | 7/29/2011 | GAM run - Management Plan | Management plan information for Santa Rita UWCD |
| GT10-033 | 1/3/2011 | GAM task | Average drawdown for the Edwards-Trinity (Plateau) and Pecos Valley aquifers within management zones in Middle Pecos GCD |
| GR10-026_MP | 8/24/2010 | GAM run - Management Plan | Management plan information for Sterling County UWCD |
| GT10-027_D | 2/9/2011 | GAM task | Predictive simulations for the Edwards (Balcones Fault Zone) and Edwards-Trinity (Plateau) aquifers in Kinney County GCD |
| GR10-022_MP | 7/9/2010 | GAM run - Management Plan | Management plan information for Uvalde County UWCD |
| GR10-018_MP | 7/27/2010 | GAM run - Management Plan | Management plan information for Menard County UWD |
| GR09-030_MP | 10/21/2009 | GAM run - Management Plan | Management plan information for Cow Creek GCD |
| GR09-011 | 9/14/2010 | GAM run | Predictive simulations for the Edwards-Trinity (Plateau) and Trinity aquifers in Groundwater Management Area 9 |
| GR09-012 | 9/14/2010 | GAM run | Predictive simulations for the Edwards-Trinity (Plateau) and Trinity aquifers in Groundwater Management Area 9 |
| GR09-024 | 9/14/2010 | GAM run | Predictive simulations for the Edwards-Trinity (Plateau) and Trinity aquifers in Groundwater Management Area 9 |
| GR09-011_S | 9/13/2010 | GAM run | Predictive simulations for the Edwards-Trinity (Plateau) and Trinity aquifers in Groundwater Management Area 9 |
| GR09-012_S | 9/13/2010 | GAM run | Predictive simulations for the Edwards-Trinity (Plateau) and Trinity aquifers in Groundwater Management Area 9 |
| GR09-024_S | 9/13/2010 | GAM run | Predictive simulations for the Edwards-Trinity (Plateau) and Trinity aquifers in Groundwater Management Area 9 |
| GR09-013_MP | 8/6/2009 | GAM run - Management Plan | Management plan information for Wes-Tex GCD |
| GR08-086_MP | 1/5/2009 | GAM run - Management Plan | Management plan information for Real Edwards Conservation and Reclamation District |
| GR09-035_D | 8/7/2010 | GAM run | Predictive simulations for the Edwards-Trinity (Plateau) and Pecos Valley aquifers in Groundwater Management Area 7 |
| GR08-075_MP | 1/23/2009 | GAM run - Management Plan | Management plan information for Middle Pecos GCD |
| GR08-074_MP | 12/9/2008 | GAM run - Management Plan | Management plan information for Kimble County GCD |
| GR08-052_MP | 7/11/2008 | GAM run - Management Plan | Management plan information for Sutton County UWCD |
| GR08-051_MP | 7/9/2008 | GAM run - Management Plan | Management plan information for Plateau UWC and Supply District |
| GR08-034_MP | 5/28/2008 | GAM run - Management Plan | Management plan information for Hickory UWCD No. 1 |
| GR08-033_MP | 5/28/2008 | GAM run - Management Plan | Management plan information for Permian Basin UWCD |
| GR08-029_MP | 5/28/2008 | GAM run - Management Plan | Management plan information for Jeff Davis County UWCD |
| GR08-027_MP | 5/21/2008 | GAM run - Management Plan | Management plan information for Crockett County GCD |
| GR08-025_MP | 5/21/2008 | GAM run - Management Plan | Management plan information for Glasscock GCD |
| GR08-013_MP | 4/8/2008 | GAM run - Management Plan | Management plan information for Sterling County UWCD |
| GR08-012_MP | 4/8/2008 | GAM run - Management Plan | Management plan information for Irion County WCD |
| GR08-008_MP | 1/25/2008 | GAM run - Management Plan | Management plan information for Lipan-Kickapoo GCD |
| GR08-007_MP | 4/29/2008 | GAM run - Management Plan | Management plan information for Headwaters GCD |
| GR07-039_MP | 4/8/2008 | GAM run - Management Plan | Management plan information for Coke County GCD |
| GR07-037 | 4/9/2008 | GAM run | Predictive simulation for the Edwards-Trinity (Plateau) Aquifer in Groundwater Management Area 7 |
| GR07-032 | 12/11/2007 | GAM run | Historic and predictive simulation for the Edwards-Trinity (Plateau) Aquifer in Groundwater Management Area 7 |
| GR07-024_MP | 9/5/2007 | GAM run - Management Plan | Management plan information for Cow Creek GCD |
| GR07-022_MP | 6/5/2007 | GAM run - Management Plan | Management plan information for Santa Rita UWCD |
| GR07-010 | 3/23/2007 | GAM run | Recharge calculations for the Edwards (Balcones Fault Zone) and Edwards-Trinity (Plateau) aquifers in Kinney County GCD |
| GR07-008_MP | 4/26/2007 | GAM run - Management Plan | Management plan information for Brewster County GCD |
| GR07-003 | 6/13/2007 | GAM run | Predictive simulation for the Edwards-Trinity (Plateau) Aquifer in Groundwater Management Area 7 |
| GR06-016 | 2/2/2007 | GAM run | Effects on river flow of various pumping scenarios in the Edwards-Trinity (Plateau) Aquifer in Terrell and Val Verde counties |
| GR06-011_MP | 7/12/2006 | GAM run - Management Plan | Management plan information for Real-Edwards Conservation and Reclamation District |
| GR05-037_MP | 11/18/2005 | GAM run - Management Plan | Management plan information for Sterling County UWCD |
| GR05-030 | 7/15/2005 | GAM run | Recharge information for the Carrizo-Wilcox, Edwards-Trinity (Plateau) and Trinity aquifers in Uvalde County |
| GR05-008 | 2/17/2005 | GAM run | Water budget for Reagan County |
| GR05-007 | 2/11/2005 | GAM run | Recharge areas in Kinney County's portions of Edwards BFZ Aquifer and Edwards-Trinity (Plateau) Aquifer (Nueces River and Rio Grande basins) |
| GR04-018 | 10/7/2004 | GAM run | Recharge rates for the Trinity Aquifer in Hays Trinity GCD |
| GR04-017 | 10/7/2004 | GAM run | Recharge rates for the Edwards-Trinity (Plateau) Aquifer in Nolan County (Wes-Tex GCD) |
| GR03-016 | 8/11/2003 | GAM run | Average annual recharge and total available storage for the Edwards-Trinity (Plateau) Aquifer in Emerald UWCD |
| GR03-003 | 5/15/2003 | GAM run | Effects of increasing well production in western Midland county |
| AA08-05 | 10/22/2009 | Aquifer assessment | Desired future condition scenarios for the Edwards-Trinity (Plateau) Aquifer in Groundwater Management Area 7 |
| GR12-006_MP | 4/11/2012 | GAM run - Management Plan | Management plan information for South Plains UWCD |
| GR12-007_MP | 6/13/2012 | GAM run - Management Plan | Permian Basin UWCD Management Plan |
| GR12-010_MP | 7/2/2012 | GAM run - Management Plan | Management plan data for Lipan-Kickapoo WCD |
| GR12-009_MP | 7/20/2012 | GAM run - Management Plan | Management plan data for Bandera County River Authority and Ground Water District |
| GR12-004_MP | 7/20/2012 | GAM run - Management Plan | Management plan data for Crockett County GCD |
| GR08-026_MP | 5/7/2008 | GAM run - Management Plan | Management plan information for Hill Country UWCD |
| 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 |
| GR12-021_MP | 9/4/2012 | GAM run - Management Plan | Management plan data for Headwaters GCD |
| GR12-015_MP | 9/4/2012 | GAM run - Management Plan | Management plan data for Hill Country UWCD |
| GR12-020_MP | 10/19/2012 | GAM run - Management Plan | Management plan data for Glasscock GCD |
| CR-0904830820 | 4/1/2010 | Contract report | Application of PEST to Re-Calibrate the Groundwater Availability Model for the Edwards-Trinity (Plateau) and Pecos Valley Aquifers |
| GR12-019_MP | 11/16/2012 | GAM run - Management Plan | Management plan data for Coke County UWCD |
| GR12-017_MP | 11/16/2012 | GAM run - Management Plan | Management plan data for Irion County WCD |
| GR13-001_MP | 1/24/2013 | GAM run - Management Plan | Management plan data for Blanco-Pedernales GCD |
| GR08-068_MP_Ver2 | 4/28/2010 | GAM run - Management Plan | Management plan information for Bandera County River Authority and Ground Water District |
| GR12-014_MP | 2/11/2013 | GAM run - Management Plan | Management plan data for Kinney County GCD |
| GR13-012_MP | 4/23/2013 | GAM run - Management Plan | Management Plan data for Terrell County GCD |
| GR13-018_MP | 7/3/2013 | GAM run - Management Plan | Management Plan data for Kimble County GCD |
| GR13-005_MP | 7/17/2013 | GAM run - Management Plan | Management Plan Information for Sutton County UWCD |
| GR13-009_MP | 7/17/2013 | GAM run - Management Plan | Management Plan Information For Plateau UWCD and SD |
| GT13-026_TERS | 9/19/2013 | GAM task - Total Estimated Recoverable Storage | Total Estimated Recoverable Storage for aquifers in Groundwater Management Area 2 |
| 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 |
| GT13-032_TERS | 10/2/2013 | GAM task - Total Estimated Recoverable Storage | Total Estimated Recoverable Storage for aquifers in Groundwater Management Area 9 |
| GR13-020_MP | 10/7/2013 | GAM run - Management Plan | Management Plan data for Brewster County GCD |
| GR13-029_MP | 11/15/2013 | GAM run - Management Plan | Management plan data for Cow Creek GCD |
| GR13-023_MP | 12/18/2013 | GAM run - Management Plan | Management plan information for Real-Edwards Conservation and Reclamation District |
| GT13-028_TERS | 1/15/2014 | GAM task - Total Estimated Recoverable Storage | Total Estimated Recoverable Storage for aquifers in Groundwater Management Area 4 |
| GR13-030_MP | 2/18/2014 | GAM run - Management Plan | Management plan data for Wes-Tex GCD |
| GR14-010_MP | 3/26/2014 | GAM run - Management Plan | Management Plan data for Middle Pecos GCD |
| GR15-008_MP | 7/2/2015 | GAM run - Management Plan | Management plan data for Menard County UWCD |
| GR15-006_MP | 6/26/2015 | GAM run - Management Plan | Management Plan data for Uvalde County UWCD |
| GR16-022_MP | 6/16/2016 | GAM run - Management Plan | Management plan data for Comal Trinity GCD |
| GR16-013_MP | 8/31/2016 | GAM run - Management Plan | Management plan information for Permian Basin UWCD |
| 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 |
| GR17-012_MP | 3/28/2017 | GAM run - Management Plan | Management plan information for Sterling County UWCD |
| GR17-022_MP | 3/28/2017 | GAM run - Management Plan | Management plan information for Crockett County GCD |
| GR17-002_MP | 4/4/2017 | GAM run - Management Plan | Management plan information for Santa Rita UWCD |
| GR17-005_MP | 5/26/2017 | GAM run - Management Plan | Management plan information for Lipan-Kickapoo Water Conservation District |
| GR17-004_MP | 11/29/2017 | GAM run - Management Plan | Management plan information for Bandera County RA&GD |
| GR17-009_MP | 1/30/2018 | GAM run - Management Plan | Management plan information for Hill Country UWCD |
| GR18-003_MP | 4/6/2018 | GAM run - Management Plan | Management plan information for Blanco-Pedernales GCD |
| GR18-001_MP | 5/10/2018 | GAM run - Management Plan | Management plan information for Reeves County GCD |
| GR17-014_MP | 6/1/2018 | GAM run - Management Plan | Management plan information for Coke County 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 |
| GR18-022_MP | 2/11/2019 | GAM run - Management Plan | Management plan information for Glasscock GCD |
| GR19-008_MP | 2/27/2019 | GAM run - Management Plan | Management plan information for Brewster County GCD |
| GR19-011_MP | 2/27/2019 | GAM run - Management Plan | Management plan information for Cow Creek GCD |
| GR19-012_MP | 6/13/2019 | GAM run - Management Plan | Management plan information for Wes-Tex GCD |
| GR19-021_MP | 2/20/2020 | GAM run - Management Plan | Management plan information for Middle Pecos GCD |
| GR21-003_MP | 4/20/2021 | GAM run - Management Plan | Management plan information for Headwaters GCD |
| GR21-004_MP | 10/11/2021 | GAM run - Management Plan | Management plan information for Menard County UWCD |
| GR22-005_MP | 5/23/2022 | GAM run - Management Plan | Management plan information for Permian Basin UWCD |
| GR22-010_MP | 8/25/2022 | GAM run - Management Plan | Management plan information for Bandera County RA & GD |
| GR22-011_MP | 11/8/2022 | GAM run - Management Plan | Management plan information for Kinney County GCD |
| GR22-013_MP | 11/8/2022 | GAM run - Management Plan | Management plan information for Lipan-Kickapoo WCD |
| GR22-014_MP | 1/23/2023 | GAM run - Management Plan | Management plan information for Irion County WCD |
| GR22-016_MP | 1/31/2023 | GAM run - Management Plan | Management plan information for Sterling County UWCD |
| GR23-001_MP | 5/10/2023 | GAM run - Management Plan | Management plan information for Reeves County GCD |
| GR23-011_MP | 06/01/2023 | GAM run - Management Plan | Management plan information for Sutton County UWCD |
| GR23-010_MP | 06/07/2023 | GAM run - Management Plan | Management plan information for Jeff Davis County UWCD |
| GR23-002_MP | 07/17/2023 | GAM run - Management Plan | Management plan information for Terrell County GCD |
| GR23-019_MP | 08/16/2023 | GAM run - Management Plan | Management plan information for Hickory UWCD #1 |
| GR23-006_MP | 08/23/2023 | GAM run - Management Plan | Management plan information for Crockett County GCD |
| GR23-017_MP | 08/30/2023 | GAM run - Management Plan | Management plan information for Blanco-Padernales GCD |
| GR23-021_MP | 09/22/2023 | GAM run - Management Plan | Management plan information for Coke County UWCD |
| GR23-004_MP | 05/31/2023 | GAM run - Management Plan | Management plan information for Hill Country UWCD |
| GR23-023_MP | 12/14/2023 | GAM run - Management Plan | Management plan information for Plateau Underground Water Conservation & Supply District |
| GR23-026_MP | 01/19/2024 | GAM run - Management Plan | Management plan information for Kimble County GCD |