Years of heavy pumpage have caused significant water-level declines in portions of the aquifer. The aquifer consists of sand, gravel, clay, and silt and has a maximum thickness of 800 feet. Map of major and minor aquifers in Texas. 1700 North Congress Avenue, Austin, TX 78701TEL: 512-463-7847 / FAX: 512-475-2053, Asset Management Program for Small Systems, State Water Implementation Fund for Texas (SWIFT), Guidance & References for Online Loan Application, State Water Implementation Fund for Texas, 6th Planning Cycle Information (2026 RWPs), 2021 Regional Water Plans & Previous Plans, Regional Water Planning Data Entry Application (RWP22) Training, District Information (O-Z and Other Districts), Extended Naturalize Flow and Reservoir Evaporation, Flood Planning Useful Links and Resources, Drought Response and Financial Assistance, Water Conservation Plan ~ Utility Profile, Historical Water Loss Audit and Conservation Annual Report Data, Industrial, Commercial & Institutional (ICI), Brackish Resources Aquifer Characterization System, Notice of Nondiscrimination and Reasonable Accommodation, Texas Natural Resources Information System (TNRIS), Texas Water Infrastructure Coordination Committee (TWICC), Texas Aquifers Study: Groundwater Quantity, Quality, Flow, and Contributions to Surface Water, An Investigation of Clouds and Precipitation for the Texas High Plains, Quantity and Chemical Quality of Low Flow in the Prairie Dog Town Fork Red River near Wayside, Texas, February 6-9,1968, Evaluating the Ground-Water Resources of the High Plains of Texas, Volumes 1-4, The High Plains Aquifer System of Texas, 1980 to 1990 - Overview and Projections, Evaluation of Ground-Water Resources in Dallam County, Texas, Evaluation of Enhanced Recharge Potential to the Ogallala Aquifer in the Brazos River Basin, Hale County, Texas, Updated Water-Quality Evaluation of the Ogallala Aquifer, Including Selected Metallic and Non-Metallic Inorganic Constituents, Studies of Playa Lakes in the High Plains of Texas, Geology and Ground-Water Resources of Hale County, Texas, Ground-Water Resources of Gaines County, Texas, Reconnaissance Investigation of the Ground-Water Resources of the Brazos River Basin, Texas, Conference Proceedings: Aquifers of the Edwards Plateau, Water-Quality Evaluation of the Ogallala Aquifer, Texas, Evaluation of Ground-Water Resources in Briscoe, Hale, and Swisher Counties, Texas, Evaluation of Ground-Water Resources in the Southern High Plains of Texas, Ground-Water Resources of Collingsworth County, Texas, Ground-Water Resources of Hall and Eastern Briscoe Counties, Texas, Water-Level Changes in the High Plains Aquifer of Texas, 1980-1990, Management plan information for Hemphill County UWCD, Management plan information for High Plains UWCD No. The effects of over-pumping removing more groundwater than what is entering an aquifer pose continual challenges for aquifer managers across the state. The Edwards (BFZ) aquifer forms a narrow belt extending through 13 counties from a groundwater divide in Kinney County through the San Antonio area northeastward to the Leon River in Bell County. The first 62 editions of the Texas Almanac are fully searchable to aid researchers and students of Texas history. Historically, Texas has had a wealth of fresh to slightly saline water, which underlies more than 81 percent of the state. 1700 North Congress Avenue, Austin, TX 78701TEL: 512-463-7847 / FAX: 512-475-2053, Asset Management Program for Small Systems, State Water Implementation Fund for Texas (SWIFT), Guidance & References for Online Loan Application, State Water Implementation Fund for Texas, 6th Planning Cycle Information (2026 RWPs), 2021 Regional Water Plans & Previous Plans, Regional Water Planning Data Entry Application (RWP22) Training, District Information (O-Z and Other Districts), Extended Naturalize Flow and Reservoir Evaporation, Flood Planning Useful Links and Resources, Drought Response and Financial Assistance, Water Conservation Plan ~ Utility Profile, Historical Water Loss Audit and Conservation Annual Report Data, Industrial, Commercial & Institutional (ICI), Brackish Resources Aquifer Characterization System, Notice of Nondiscrimination and Reasonable Accommodation, Texas Natural Resources Information System (TNRIS), Texas Water Infrastructure Coordination Committee (TWICC), Texas Aquifers Study: Groundwater Quantity, Quality, Flow, and Contributions to Surface Water, Reevaluation of desired future conditions for the Trinity Aquifer in Comanche and Erath counties, Reconnaissance Investigation of the Ground-Water Resources of the Brazos River Basin, Texas, Geology and Ground-Water Resources of Uvalde County, Texas, Ground-Water Geology of Bexar County, Texas, Ground-Water Resources of Guadalupe County, Texas, Changes in Groundwater Conditions in the Edwards and Trinity Aquifers, 1987-1997, for Portions of Bastrop, Bell, Burnet, Lee, Milam, Travis, and Williamson Counties, Texas, Ground-Water Resources of Bastrop County, Texas, Ground-Water Resources of Navarro County, Texas, Geology and Ground-Water Resources of Medina County, Texas, Geology and Ground-Water Resources of Hays County, Texas, Ground-Water Geology of Bandera County, Texas, Occurrence and Quality of Ground Water in Brown County, Texas, Occurrence and Quality of Ground Water in Montague County, Texas, Occurrence, Availability, and Chemical Quality of Ground Water in the Edwards Plateau Region of Texas, Ground-Water Evaluation in and Adjacent to Dripping Springs, Texas, Occurrence, Availability, and Quality of Ground Water in Travis County, Texas, Ground-Water Resources of Kerr County, Texas, Ground-Water Resources of Blanco County, Texas, Base-Flow Studies, Upper Guadalupe River Basin, Texas, Quality and Quantity, Ground-Water Availability of the Lower Cretaceous Formations in the Hill Country of South-Central Texas, Groundwater Availability of the Trinity Aquifer, Hill Country Area, Texas: Numerical Simulations through 2050, Occurrence, Quantity, and Quality of Ground Water in Taylor County, Texas, Ground-Water Quality Monitoring of the Trinity Aquifer in the Vicinity of Erath County, Occurrence, Availability and Chemical Quality of Ground Water in the Cretaceous Aquifers of North-Central Texas, Volumes 1 & 2, Ground-Water Resources of Part of Central Texas with Emphasis on the Antlers and Travis Peak Formations, Volumes 1 & 2, Evaluation of Water Resources in Part of Central Texas, The Paleozoic and Related Aquifers of Central Texas, Evaluation of Ground-Water Resources of the Paleozoic and Cretaceous Aquifers in the Hill Country of Central Texas, Updated Evaluation of Water Resources in Part of North-Central Texas, 1990-1999, Evaluation of Water Resources in Part of North-Central Texas, Occurrence and Quality of Ground Water in Jack County, Texas, Groundwater Availability Model: Hill Country Portion of the Trinity Aquifer of Texas, Desired future condition scenarios for the middle and lower Trinity Aquifer in Groundwater Management Area 10, Desired future condition scenarios for the Trinity Aquifer in Groundwater Management Area 10, Management plan information for Prairielands GCD, Management plan information for Central Texas GCD, Management plan information for North Texas GCD, Management plan information for Red River GCD, Management plan information for Post Oak Savannah GCD, Additional results from the analysis completed in GAM Task 10-005, Management plan information for Lost Pines GCD, Management plan information for Clearwater UWCD, Management plan information for Middle Trinity GCD, Management plan information for Hays Trinity GCD, Management plan information for Medina County GCD, Management plan information for Cow Creek GCD, Predictive simulations for the Edwards-Trinity (Plateau) and Trinity aquifers in Groundwater Management Area 9, Management plan information for Upper Trinity GCD, Management plan information for Neches & Trinity Valleys GCD, Additional results from the analysis completed in GAM Run 08-064, Predictive and steady-state simulations for the Trinity Aquifer in Groundwater Management Area 9, Management plan information for McLennan County GCD, Predictive simulation for the Woodbine and Trinity aquifers in Groundwater Management Area 8, Management plan information for Northern Trinity GCD, Management plan information for Fox Crossing Water District, Management plan information for Saratoga UWCD, Predictive simulation for the Trinity Aquifer in Groundwater Management Area 9, Predictive simulations for the Trinity Aquifer in Groundwater Management Area 8, Simulation to document locations and discharges to springs and rivers, and document the water budget in Groundwater Management Area 9, Predictive simulation for the Trinity Aquifer in Groundwater Management Area 8, Predictive simulation for the Trinity Aquifer in Lampasas County (Saratoga UWCD), Predictive simulation for the Trinity Aquifer in Mills County, Effects on Guadalupe River flow from various pumping scenarios in the Trinity Aquifer, Recharge information for the Carrizo-Wilcox, Edwards-Trinity (Plateau) and Trinity aquifers in Uvalde County, Recharge information for the Carrizo-Wilcox and Trinity aquifers in Medina County, Recharge rates for the Trinity Aquifer in Hays Trinity GCD, Analytical groundwater modeling to estimate water level drawdown in Erath and Comanche counties, Analytical groundwater modeling to assess water level drawdown by implementing hypothetical well fields, Decadal water level declines for the Upper and Middle Trinity aquifers of the Trinity (Hill Country) GAM, Recharge, leakage, and total storage for the Trinity (Hill Country) in Bandera County River Authority and GCD, Water budget, storage, and drawdown in 2050 for the Trinity (Hill Country) and Carrizo-Wilcox aquifers in Medina County GCD, Water budget by county for the Trinity (Hill Country) Aquifer, Estimated water levels at specified locations in the Trinity (Hill Country) GAM, Average well yield in Kendall County for the Trinity (Hill Country) Aquifer GAM, Managed available groundwater estimates for the Trinity Aquifer in Groundwater Management Area 8, Trinity Aquifer model runs for Central Texas GCD, County water budget for the Trinity (Hill Country) Aquifer GAM, Predictive simulations for the Trinity Aquifer in Clearwater UWCD, Modeled available groundwater for the Trinity Aquifer in Groundwater Management Area 10, Aquifer Test and Related Well Information from Public Water Supply Wells in Groundwater Management Area 8, Management plan data for Hill Country UWCD, Ground Water Recharge Model: Calibration and Validation for Remotely-Sensed Dual Coefficient (RDC) GMA8 ET Estimation, Management plan information for Blanco-Pedernales GCD, Management plan data for Blanco-Pedernales GCD, Management plan data for Neches & Trinity Valleys GCD, Management plan data for Middle Trinity GCD, GAM task - Total Estimated Recoverable Storage, Total Estimated Recoverable Storage for aquifers in Groundwater Management Area 6, Total Estimated Recoverable Storage for aquifers in Groundwater Management Area 7, Total Estimated Recoverable Storage for aquifers in Groundwater Management Area 9, Total Estimated Recoverable Storage for aquifers in Groundwater Management Area 10, Total Estimated Recoverable Storage for aquifers in Groundwater Management Area 13, Management plan information for Real-Edwards Conservation and Reclamation District, Total Estimated Recoverable Storage for aquifers in Groundwater Management Area 8, Total Estimated Recoverable Storage for aquifers in Groundwater Management Area 11, Total Estimated Recoverable Storage for aquifers in Groundwater Management Area 12, Management plan data for Southern Trinity GCD, Management plan information for Trinity-Glen Rose GCD, Management plan data for Trinity Glen Rose GCD, Management Plan data for Southern Trinity GCD, Management plan data for Hays Trinity GCD, Management plan data for Upper Trinity GCD, Management plan data for Northern Trinity GCD, Predictive simulations for the Trinity Aquifer in Groundwater Management Area 9, Management plan data for Medina County GCD, Management Plan data for Uvalde County UWCD, Management plan information for Middle Trinity GCD, Management plan data for Comal Trinity GCD, Management plan information for Headwaters GCD, Management plan information for Bandera County RA&GD, Management plan information for Hill Country UWCD, Management plan information for Neches and Trinity Valleys GCD, Management plan information for Southern Trinity GCD, Management plan information for Glen Rose GCD, Management plan information for Southwestern Travis County GCD, Management plan information for Bandera County RA & GD, Management plan information for Comal Trinity GCD, Proportion of aquifer with groundwater conservation districts: 88 percent, Number of counties containing the aquifer: 61. The pages below contain descriptionsand maps of these main aquifer types: These pages, formerly hosted at ourAquifer Basicswebsite,provide ageneral summary of information published in the Ground Water Atlas of the United States. Elsewhere, water from the Trinity Aquifer is used primarily for municipal and domestic supply.