About 32 percent of water used to meet municipal demands is from groundwater. Until recently, San Antonio was one of the largest cities in the world that relied solely on a single groundwater source for its municipal supply. About 60 percent of the approximately 16 million acre-feet of water used yearly in Texas is derived from underground formations that make up 9 major and 22 minor aquifers (for map of minor aquifers, click). Elsewhere, water from the Trinity Aquifer is used primarily for municipal and domestic supply. The Trinity Aquifer consists of basal Cretaceous-age Trinity Group formations extending through 61 counties from the Red River in North Texas to the Hill Country of Central Texas. An official website of the United States government. Last fall while exploring for oil and gas deposits in southwest Texas, a driller instead found a huge freshwater deep aquifer. N or S, where N = aquifer, S = aquifer system, 3 digit number = rock type (4 digits used for "Other" to fill out the code), 100-- Sand and gravel aquifers200--Semiconsolidatedsand aquifers (not used)300--Sandstone aquifers400--Carbonate-rock aquifers500--Sandstone and carbonate-rock aquifers600--Igneous and metamorphic-rock aquifers9999--Areas that are not a national aquifer, 6 character identifier derived from the aquifer name using thecode derivation procedure also used for GWSI geohydrologic unit names. Below are other webpages associated with principal aquifers. PrefaceThe Ground Water Atlas of the United States presents a comprehensive summary of the Nation's ground-water resources and is a basic reference for the location, geography, geology, and hydrologic characteristics of the major aquifers in the Nation. Computer models of the northern and southern portions of the Ogallala aquifer were completed by the Texas Water Development Board and its contractor. The aquifer underlies an extensive area in south-central Texas extending along the Balcones fault zone from Kinney County eastward to San Antonio, and thence northeastward to Hays County. Does your community have an annual fair or festival you'd like to have listed on our site, or in the next Texas Almanac? The areal and vertical location of major aquifers is fundamental to the determination of groundwater availability for the Nation. See more information on Water Issues and the Texas economy. Although referred to differently in different parts of the state, they include the Antlers, Glen Rose, Paluxy, Twin Mountains, Travis Peak, Hensell, and Hosston aquifers. Historical large-scale groundwater withdrawals, especially for the municipal uses of El Paso and Juarez, have caused major water-level declines and significantly changed the direction of flow, causing a deterioration of the chemical quality of the groundwater in the aquifer, according to El Paso Water Utilities and the USGS. The recharge zone of the aquifer in Burnet County is approximately 18,011 acres. Texas State Historical Association. The Hueco Bolson, located on the eastern side of the Franklin Mountains, consists of up to 9,000 feet of clay, silt, sand, and gravel and is an important source of drinking water for both El Paso and Juarez, Mexico. A two-dimensional map representation of the principal aquifers of the Nation is shown below. In 2019, more than 90 percent of the water pumped from the Ogallala was used for irrigation, while more than 90 percent of the Hueco-Mesilla pumpage served municipal purposes. Declines continue in Ward County due to increased municipal and industrial pumping. Elevation (ft) Well Depth (ft) Water Level Observation Type. In 2019, more than 4.4 million acre-feet were pumped from the Ogallala Aquifer, accounting for 67 percent of the water sourced from all major Texas aquifers. El Paso and Fort Bliss also have built the worlds largest inland desalination plant in El Paso County, which uses brackish groundwater from the Hueco Bolson. Located west of the Franklin Mountains, the Mesilla Bolson reaches up to 2,000 feet in thickness and contains three separate water-producing zones. Guadalupe runs dry with rainfall scarce. In scattered places in the United States, carbonate rocks are interbedded with almost equal amounts of water-yielding sandstone. A .gov website belongs to an official government organization in the United States. The lower, more permeable part of the aquifer produces the greatest amount of groundwater. The Ogallala aquifer extends through 48 counties of the Texas Panhandle and is the southernmost extension of the largest aquifer (High Plains aquifer) in North America. Aquifers shown on the 2003PrincipalAquifers map, with some additions, were used as the first National AquiferReferenceList in the USGSNational Water Information System(NWIS) in theAggregate Water Use Data System(AWUDS,database released in August 2001). Adopt the TX Town or County of your choice and share your message with the world. 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, Stratigraphic and Hydrogeologic Framework of Part of the Coastal Plain of Texas, Ground-Water Geology of Live Oak County, Texas, Ground-Water Resources of La Salle and McMullen Counties, Texas, Evaluation of Ground-Water Quality in Texas Counties Bordering the Rio Grande, Transmissivity, Hydraulic Conductivity, and Storativity of the Carrizo-Wilcox Aquifer in Texas, Ground-Water Resources of the Carrizo-Wilcox Aquifer in the Central Texas Region, Reconnaissance Investigation of the Ground-Water Resources of the Brazos River Basin, Texas, Ground-Water Resources of Grimes County, Texas, Ground-Water Resources of Brazos and Burleson Counties, Texas, Evaluation of Ground Water Resources in the Vicinity of the Cities of Henderson, Jacksonville, Kilgore, Lufkin, Nacogdoches, Rusk, and Tyler in East Texas, Geology and Ground-Water Resources of Uvalde County, Texas, Geology and Ground-Water Resources of Dimmit County, Texas, Ground-Water Geology of Bexar County, Texas, Ground-Water Geology of Wilson County, Texas, Ground-Water Resources of Guadalupe County, Texas, Ground-Water Resources of Caldwell County, Texas, Ground-Water Resources of Gonzales County, Texas, Availability and Quality of Ground Water in Leon County, Texas, Ground-Water Conditions in Anderson, Cherokee, Freestone, and Henderson Counties, Texas, Ground-Water Resources of Bastrop County, Texas, Ground-Water Resources of Lee County, Texas, Ground-Water Resources of Navarro County, Texas, A Digital Model of the Carrizo-Wilcox Aquifer Within the Colorado River Basin of Texas (cross-section figures, Availability and Quality of Ground Water in Smith County, Texas, Ground-Water Resources of Camp, Franklin, Morris, and Titus Counties, Texas, Ground-Water Resources of Houston County, Texas, Ground-Water Resources of Harrison County, Texas, Ground-Water Resources of Sabine and San Augustine Counties, Texas, Ground-Water Resources of Wood County, Texas, Ground-Water Resources of Gregg and Upshur Counties, Texas, Ground-Water Conditions in Angelina and Nacogdoches Counties, Texas, Ground-Water Resources of Rusk County, Texas, Geology and Ground-Water Resources of Medina County, Texas, Ground-Water Resources of Atascosa and Frio Counties, Texas, Ground-Water Resources of Rains and Van Zandt Counties, Texas, Availability and Quality of Ground Water in Fayette County, Texas, Depth to aquifer layers for the Carrizo-Wilcox, Queen City, and Sparta aquifers in McMullen County, Management plan information for Post Oak Savannah GCD, Predictive simulations for the Carrizo-Wilcox, Queen City, Sparta, and Yegua-Jackson aquifers in Groundwater Management Area 11, Management plan information for Wintergarden GCD, Analysis of pumping information for the Carrizo-Wilcox, Queen City, and Sparta aquifers in Groundwater Management Area 12, Management plan information for Uvalde County UWCD, Management plan information for Evergreen UWCD, Management plan information for Lost Pines GCD, Management plan information for Brazos Valley GCD, Management plan information for Live Oak UWCD, Predictive simulations for the Carrizo-Wilcox, Queen City, and Sparta aquifers in Groundwater Management Area 13, Management plan information for Medina County GCD, Management plan information for Neches & Trinity Valleys GCD, Management plan information for Rusk County GCD, Management plan information for Bluebonnet GCD, Predictive simulation for the Carrizo and Middle Wilcox aquifers in Anderson County, Management plan information for Mid-East Texas GCD, Management plan information for Panola County GCD, Management plan information for Pineywoods GCD, Predictive simulation for the Carrizo-Wilcox, Queen City, and Sparta aquifers in Groundwater Management Area 13, Average drawdowns by county for GAM Runs 08-41, 08-42, and 08-43 in Groundwater Management Area 13, Management plan information for Pecan Valley GCD, Management plan information for Fayette County GCD, Management plan information for McMullen GCD, Management plan information for Guadalupe GCD, Predictive simulation for the Carrizo-Wilcox, Queen City, and Sparta aquifers in Groundwater Management Area 11, Management plan information for Anderson County UWCD, Average drawdowns for the Carrizo-Wilcox, Queen City, and Sparta aquifers based on the analysis completed in GAM Run 06-029, Predictive simulation for the Carrizo-Wilcox, Queen City, and Sparta aquifers in Fayette County GCD, Management plan information for Plum Creek Conservation District, Predictive simulation for the Carrizo-Wilcox, Queen City, and Sparta aquifers in Mid-East Texas GCD, Predictive simulation for the Carrizo-Wilcox Aquifer in Rusk County GCD, Impacts of pumping increases in the in the Carrizo-Wilcox Aquifer near Jewett, Texas (Leon County), 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, Water level information for the Gulf Coast, Carrizo-Wilcox, Queen City, and Sparta aquifers in Live Oak County, Water budget information for the Carrizo-Wilcox, Queen City, and Sparta aquifers in Bee, Live Oak, and McMullen counties, Post Oak Savannah GCD, water budget, water levels, drawdown through 2050, 2002 State Water Plan pumping summary, and interaction with the Brazos River Alluvium Aquifer, Statistical summary and map of storage coefficient for the Simsboro Aquifer in Burleson County, Statistical summary and map of transmissivity of the Simsboro Aquifer in Burleson County, Recharge amounts and maximum pumping needed to maintain current water levels in Mid-East Texas GCD, Aquifer recharge values for Neches and Trinity Valleys GCD, Recharge amounts and maximum pumping that allows maintaining current water levels in Mid-East Texas GCD, Predictive run using Region C provided pumping, Predictive run using pumping data provided by Post Oak Savannah GCD, Water budget and total storage above 4000 depth in Evergreen UWCD, Total water availability in Henderson, Navarro, and Freestone counties, Recharge information and total storage above 3000 feet using a predictive simulation in Milam and Burleson counties, Recharge and total storage data for the Carrizo-Wilcox, Queen City, Sparta, and Gulf Coast aquifers in Fayette County GCD, Water budget, storage, and water level drawdown for the Carrizo-Wilcox Aquifer and recharge information for the Gulf Coast Aquifer in Bee GCD, Water availability for the Carrizo-Wilcox Aquifer in Henderson, Navarro, and Freestone counties, 20102030 water level drawdowns for the Carrizo-Wilcox Aquifer in Rusk, Smith, and Gregg counties, Water budget, storage, and drawdown in 2050 for the Trinity (Hill Country) and Carrizo-Wilcox aquifers in Medina County GCD, Recharge, available storage, estimated and projected declines for the Carrizo-Wilcox Aquifer in Pineywoods GCD, Estimated drawdown under assumed future pumping for the Carrizo-Wilcox, Queen City, and Sparta aquifers in Groundwater Management Area 13, Drawdown maps and water budget for GAM run 11-007, Predictive simulations for the Carrizo-Wilcox, Queen City, and Sparta aquifers in Groundwater Management Area 11, Management plan information for Gonzales County UWCD, Management plan data for Panola County GCD, Management plan data for Fayette County GCD, GAM run - Total Estimated Recoverable Storage, Total Estimated Recoverable Storage for aquifers in Groundwater Management Area 16, Management Plan data for Gonzales County UWCD, Management plan data for Neches & Trinity Valleys GCD, Management plan data for Mid-East Texas GCD, GAM task - Total Estimated Recoverable Storage, Total Estimated Recoverable Storage for aquifers in Groundwater Management Area 13, Total Estimated Recoverable Storage for aquifers in Groundwater Management Area 15, Management Plan data for Brazos Valley GCD, Total Estimated Recoverable Storage for aquifers in Groundwater Management Area 11, Total Estimated Recoverable Storage for aquifers in Groundwater Management Area 12, Total Estimated Recoverable Storage for aquifers in Groundwater Management Area 14, Predictive run using pumping distribution provided by Post Oak Savannah GCD, Management plan data for Medina County GCD, Management Plan data for Uvalde County UWCD, Management Plan data for Wintergarden GCD, Management plan information for Neches and Trinity Valleys GCD, Proportion of aquifer with groundwater conservation districts: 65 percent, Number of counties containing the aquifer: 66. Proceeds benefit education in TX. Individual accumulations vary greatly in thickness, but most of the Seymour is less than 100 feet. The surface extent, or outcrop, of each aquifer is the area in which the host formations are exposed at the land surface. . In general, groundwater is fresh but very hard in the outcrop of the aquifer. The aquifer is primarily composed of sand locally interbedded with gravel, silt, clay, and lignite. For study or mapping purposes, aquifers are often combined into aquifer systems. Click any position on the map to reveal attributes for a specific location. It's very responsive to the weather and very responsive to drought, unfortunately. Water Use. San Antonio In 2005,thenational aquiferinformationwas addedto NWIS, allowing users to search by national aquifer code and name from the reference list below. Their combined freshwater saturated thickness averages about 600 feet in North Texas and about 1,900 feet in Central Texas. Water in the aquifer occurs in fractures, honeycomb zones (or intergranular pores), and solution channels in the Edwards and associated limestone formations of Cretaceous age. This map, which was derived fromGround Water Atlas of the United Statesdata (published as part of the National Atlas in 1998, revised 2003) indicates the areal extent of the uppermost principal aquifers on a national scale. The Wilcox Group and overlying Carrizo Sand form a hydrologically connected system of sand locally interbedded with clay, silt, lignite, and gravel. Where the Glen Rose thins or is absent, the Twin Mountains and Paluxy formations coalesce to form the Antlers Formation. Beets will help keep Bexar County roads from freezing this week. Throughout most of its extent in Texas, the aquifer yields fresh to slightly saline water that is used mainly for irrigation in the Winter Garden District of South Texas, and for public supply and industrial use in Central and Northeast Texas. Such sites will not be retrieved using this search criteria. The aquifer consists of sand, gravel, clay, and silt and has a maximum thickness of 800 feet. Aquifers are identified by a geohydrologic unit code - a three-digit number related to the age of the formation, followed by a 4 or 5 character abbreviation for the geologic unit or aquifer name. The Ground Water Atlas of the United States is available onlineas anHTML website, asdownloadable PDFs, andoravailable for purchasethrough the USGS Store. Aquifers are identified by a geohydrologic unit code-a three-digit number related to the age of the formation, followed by a 4 or 5 character abbreviation for the geologic unit or aquifer name. AWUDS has a graphical user interface that facilitates data entry, revision, review, and approval. For an overview ofprincipalaquifers:The principal water-yielding aquifers of North America can be grouped into five types by rock type and location: unconsolidated and semiconsolidated sand and gravel aquifers, sandstone aquifers, carbonate-rock aquifers, aquifers in interbedded sandstone and carbonate rocks, and aquifers in igneous and metamorphic rocks. We are the premier source for trusted information about Texas. About 55 percent of all water used in Texas was sourced through aquifers in 2019. Freshwater saturated thickness averages 95 feet. Browse our curated list of helpful links for students and researchers. This is an important step in planning for water in Texas and Bastrop County for the next 50 years. Refer to the metadata for a complete description of the files and how they were generated. Below are publications associated with national aquifers. It is composed of several smaller aquifers contained within the Trinity Group. The aquifer is comprised of the Twin Mountains, Glen Rose, Paluxy, Hosston, and Hensell formations. The Texas Water Development Board (TWDB) recognizes 9 major aquifers aquifers that produce large amounts of water over large areas (see major aquifers map) and 22 minor aquifers aquifers that produce minor amounts of water over large areas or large amounts of water over small areas (see minor aquifers map). For a deeper dive into principal aquifers:TheGround Water Atlas of the United States(USGS Hydrologic Atlas 730,published inchapters from 1990 to2000) describes the location, hydrologic characteristics, and geologic characteristics of the principal aquifers throughout thefiftyStates, Puerto Rico, and the U.S. Virgin Islands. Consisting of up to 1,500 feet of alluvial fill, the aquifer occupies two hydrologically separate basins: the Pecos Trough in the west and the Monument Draw Trough in the east. TWDB maps depict the 9 major and 21 minor aquifers. Would you like to submit an article, provide feedback, or just get in touch? Natural salt pollution in the upper reaches of the Red and Brazos river basins precludes the full utilization of these water resources. Revisions to the reference list since it was first used by NWIS: Northern Great Plains aquifer system was removed:this umbrella term includes four national aquifers but is not considered a national aquifer itself. Irrigation accounts for more than half of the aquifer's discharge. Texas Water Development Board works best with JavaScript enabled, 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).