Publication_Date: 20050901 Title: Edwards Aquifer Protection Program, Chapter 213 Rules - Recharge Zone, Transition Zone, Contributing Zone, and Contributing Zone Within the Transition Zone. This dataset represents the geographic areas identified in TCEQ rules as being subject to regulation under the Edwards Aquifer Protection Program. The coverage was derived from existing official hard copy maps, containing regulatory boundaries based on previous geologic interpretation of the Edwards Aquifer Recharge, Transition, Contributing and Contributing Within the Transition zones, as defined in 30 TAC 213. This dataset contains lines, area features and zone types attributes extended to all 90 USGS 7.5-minute maps under TCEQ rules. Effective September 1, 2005, amended 30 TAC 213 changes the designation of portions of four areas in northern Hays and southern Travis Counties. The commission adopts changes from transition zone to contributing zone within the transition zone, from transition zone to recharge zone and from recharge zone to transition zone. These changes were made to regulatory zone boundaries on the Oak Hill 7.5 Minute Quadrangle, the Mountain City 7.5 Minute Quadrangle, and the Buda 7.5 Minute Quadrangle. Also effective September 1, 2005, with this amendment, the commission is adopting changes from transition zone to recharge zone, and contributing zone within the transition zone; in southern Hays and Comal Counties for areas along the eastern boundary of the recharge zone in the vicinity of the Blanco River, the City of San Marcos, the City of New Braunfels, the community of Hunter and the community of Garden Ridge. Changes are depicted on the Mountain City 7.5 Minute Quadrangle; on the San Marcos North 7.5 Minute Quadrangle; on the San Marcos South 7.5 Minute Quadrangle; on the Hunter 7.5 Minute Quadrangle; and on the Bat Cave 7.5 Minute Quadrangle. The commission also adopted changes along the western boundary of the recharge zone in southern Hays and Comal Counties. Effective September 1, 2005, areas are changed from contributing zone to recharge zone in the Guadalupe River basin, and other areas in the Guadalupe River basin, and near Wimberley are changed from recharge zone to contributing zone. These changes occur on the Smithson Valley, Sattler, Devil’s Backbone and Wimberley 7.5 Minute Quadrangles. Another area near Hays City was changed to recharge zone from contributing zone, and is changed accordingly in the Driftwood 7.5 Minute Quadrangle. Purpose: This dataset provides TCEQ regional office and public with information on Edwards Aquifer Protection areas and types, including changes made to the boundaries by the most recent rules revisions, according to 30 TAC Ch. 213 (1999). This coverage is to facilitate the eventual replacement of the hard copy maps, historically used to identify the geographic location of Edwards Aquifer Protection Program regulated areas. The purpose of the TCEQ Rule 30, Texas Administrative Code(TAC), Chapter 213 is to regulate activities having the potential for polluting the Edwards Aquifer and hydrologically connected surface streams in order to protect existing and potential uses of ground- water and maintain Texas Surface Water Quality Standards. The following definitions are founded under Chapter: The Edwards Aquifer - portion of an arcuate belt of porous, waterbearing, predominantly carbonate rocks known as the Edwards (Balcones Fault Zone) Aquifer trending from west to east to north- east in Kinney, Uvalde, Medina, Bexar, Comal, Hays, Travis, and Williamson Counties; and is composed of the Salmon Peak Limestone, McKnight Formation, West Nueces Formation, Devil's River Limestone, Person Formation, Kainer Formation, Edwards Group and Georgetown Formation. The permeable aquifer units generally overlie the less- permeable Glen Rose Formation to the south, overlie the less- permeable Comanche Peak and Walnut formations north of the Colorado River, and underlie the less-permeable Del Rio Clay regionally. (30 TAC, § 213.3(8) ) Recharge Zone - area where the stratigraphic units constituting the Edwards Aquifer crop out, including the outcrops of geologic form- ations in proximity to the Edwards Aquifer where caves, sinkholes, faults, fractures, or other permeable features would create a potential for recharge to surface waters into the Edwards Aquifer. (30 TAC, § 213.3(25) ) Transition Zone - area where geologic formations crop out in proximity to and south and southeast of the recharge zone and where faults, fractures, and other geologic features present a possible avenue for recharge of surface water to the Edwards Aquifer, including portions of the Del Rio Clay, Buda Limestone, Eagle Ford Group, Austin Chalk, Pecan Gap Chalk, and Anacacho Limestone. ( 30 TAC, § 213.3(34) ) Contributing Zone - The area or watershed where runoff from precipitation flows downgradient to the recharge zone of the Edwards Aquifer. The Contributing Zone is located upstream (upgradient) and generally north and northwest of the Recharge Zone for the following counties: (A) all areas within Kinney County, except the area within the watershed draining to Segment 2304 of the Rio Grande Basin; (B) all areas within Uvalde, Medina, Bexar, and Comal Counties; (C) all areas within Hays and Travis Counties, except the area within the watersheds draining to the Colorado River above a point 1.3 miles upstream from Tom Miller Dam, Lake Austin at the confluence of Barrow Brook Cove, Segment 1403 of the Colorado River Basin; and (D) all areas within Williamson County, except the area within the watersheds draining to the Lampasas River above the dam at Stillhouse Hollow reservoir, Segment 1216 of the Brazos River Basin. ( 30 TAC, §213.22(2) )
Contributing Zone Within the Transition Zone - The area or watershed where runoff from precipitation flows downgradient to the Recharge Zone of the Edwards Aquifer. The Contributing Zone Within the Transition Zone is located downstream (downgradient) and generally south and southeast of the Recharge Zone and includes specifically those areas where stratigraphic units not included in the Edwards Aquifer crop out at topographically higher elevations and drain to stream courses where stratigraphic units of the Edwards Aquifer crop out and are mapped as Recharge Zone. ( 30 TAC, § 213.22(3) )

The Texas Water Development Board classifies the karstic Edwards and Trinity aquifers as major sources of water in south-central Texas. To effectively manage the water resources in the area, detailed maps and descriptions of the geologic framework and hydrostratigraphic units of the aquifers outcropping in Hays County, Tex. are needed. In 2016 and 2018, the U.S. Geological Survey, in cooperation with the Edwards Aquifer Authority, mapped the geologic framework and hydrostratigraphy of the Edwards and Trinity aquifers within Hays County, Tex. at 1:24,000 scale. These digital data accompany Clark, A.K., Pedraza, D.E., and Morris, R.R., 2018, Geologic framework and hydrostratigraphy of the Edwards and Trinity aquifers within Hays County, Texas: U.S. Geological Survey Scientific Investigations Map 3418, pamphlet XX p., 1 sheet, scale 1:24,000, https://doi.org/10.3133/sim3418.

delineates the land use/land cover (LULC) polygons for the Edwards Aquifer Project in Texas from the years 1995 and 1996. Attribution of the polygons is based on a modified Anderson classification schema. LULC classification was done to Level 3 of the classification schema and a new category of Mixed Forest/Shrub was added to better represent the land cover of the area. Fieldwork was performed prior to compilation to gather local data and relate aerial photo images to corresponding ground features. Because of the stunted or lower tree growth common in this region it was difficult at times to differentiate between Forest, Mixed Forest/Shrub, and Shrub. It should be noted that much of the Planted/cultivated land is highly managed pastureland.

This layer contains the Edwards Aquifer, provided by the Texas Commission on Environmental Quality (TCEQ) and maintained by the City of Round Rock GIS/IT Department, located in Williamson County, Texas. The data in this layer are represented as polygons. An aquifer is an underground layer of water-bearing permeable rock, rock fractures or unconsolidated materials. Groundwater can be extracted using a water well. The study of water flow in aquifers and the characterization of aquifers is called hydrogeology. The Edwards Aquifer is one of the most prolific artesian aquifers in the world. Located on the eastern edge of the Edwards Plateau in the U.S. state of Texas, it is the source of drinking water for two million people, and is the primary water supply for agriculture and industry in the aquifer's region.

This geodatabase contains the spatial datasets that represent the Edwards-Trinity aquifer system in the States of Arkansas, Oklahoma, and Texas. Included are:

(1) polygon extents; datasets that represent the aquifer system extent, the entire extent subdivided into subareas or subunits, and any polygon extents of special interest (no data available, areas underlying other aquifers, anomalies, for example),

(2) raster datasets for the altitude of each aquifer subarea or subunit,

(3) altitude, and/or if applicable, thickness contours used to generate the surface rasters,

(4) georeferenced images of the figures that were digitized to create the altitude or thickness contours. The images and digitized contours are supplied for reference.

The extent of the Edwards-Trinity aquifer system encompasses all subunits. It is delineated from the linework of the Edwards-Trinity aquifer system extent and outcrop maps of the U.S. Geological Survey Hydrologic Atlas 73 ...

These iterations of a concept map surrounding the idea of being sustainable with the Edwards Aquifer. The less specific mental modeler concept map is the final product showing how the most positive and negative factors can relate to one another in affecting the aquifer itself. This allowed the understanding of how to interrelate these factors on the respective programs of Insight Maker, Matlab, and Twine in creating our models.

The Edwards and Trinity aquifers are major sources of water in south-central Texas and are both classified as major aquifers by the State of Texas. The population in Hays and Comal Counties is rapidly growing, increasing demands on the area's water resources. To help effectively manage the water resources in the area, refined maps and descriptions of the geologic structures and hydrostratigraphic units (HSUs) of the aquifers are needed. This digital map database presents the detailed 1:24,000-scale bedrock hydrostratigraphic map as well as names and descriptions of the geologic and hydrostratigraphic units of the Driftwood and Wimberley 7.5-minute quadrangles in Hays and Comal Counties, Tex.

The karstic Edwards and Trinity aquifers are classified as major sources of water in south-central Texas by the Texas Water Development Board, and both are classified as major aquifers by the State of Texas. The Edwards and Trinity aquifers developed because of the original depositional history of the carbonate limestone and dolomite rocks that contain them, and the primary and secondary porosity, diagenesis, fracturing, and faulting that modified the porosity, permeability, and transmissivity of each aquifer and of the geologic units separating the aquifers. Previous studies such as those by the U.S. Geological Survey (USGS) and the Edwards Aquifer Authority (EAA) have mapped the geology, hydrostratigraphy, and structure in these areas at various scales. The purpose of this data release is to present the data that were collected and compiled to describe the geologic framework and hydrostratigraphy of northern Medina county, Texas in order to help water managers, water purveyors, and local residents better understand and manage water resources. The scope of the larger work and this accompanying data release is focused on the geologic framework and hydrostratigraphy of the outcrops and hydrostratigraphy of the rocks that contain the Edwards and Trinity aquifers within northern Medina county, Texas. These digital data accompany Clark and others (2024), which supersedes Scientific Investigations Map 3461.

This data release supports the U.S. Geological Survey Scientific Investigation Map (SIM) by Clark and others (2020) by documenting the data used to create the geologic maps and describe geologic framework and hydrostratigraphy of the Edwards and Trinity aquifers for a 442 square-mile area in northern Medina County in south Texas. The karstic Edwards and Trinity aquifers that are the subject of the SIM by Clark and others (2020) are classified as major sources of water in south-central Texas by the Texas Water Development Board (George and others, 2011). The geologic framework and hydrostratigraphy of the Edwards and Trinity aquifers largely control groundwater-flow paths and storage in northern Medina County (Kuniasky and Ardis, 2004). The data provided in this data release and the detailed maps and descriptions of the geologic framework and hydrostratigraphy in Clark and others (2020) are intended to help provide water managers information that is useful for effectively managing ...

These are the figures used in the interface. Two show the 3rd and 5th critical stages of the Edwards Aquifer J17 index well, while another is a map of the Edwards Aquifer. These figures are from the Aquiferium Project headed by Encompass Labs, the Edwards Aquifer Authority, and the University of Texas at Austin.

Confirmed districts are arranged in alphabetical order. Dates indicate when district was established by law or election. * Districts that have, in whole or part, authority as assigned by Chapter 36 of the Texas Water Code. Please refer questions pertaining to individual districts to the district themselves. (www.twdb.texas.gov/groundwater/conservation_districts/index.asp) ** The subsidence districts and the Edwards Aquifer Authority are not groundwater conservation districts as defined under Chapter 36 of the Texas Water Code, but have the ability to regulate groundwater production (Senate Bill 1537 from the 79th Legislative Session and House Bill 2729 from the 86th Legislative Session). Groundwater Conservation District GIS Data created by the Texas Commission on Environmental Quality. For more information, please contact TCEQ at 512-239-1000 or wras@tceq.texas.gov. DISCLAIMER: This map was generated by the Texas Water Development Board using GIS (Geographical Information System) software. No claims are made to the accuracy or completeness of the information shown herein nor to its suitability for a particular use. The scale and location of all mapped data are approximate. Map date: NOV-2019

This layer represents the boundaires of watersheds which have a contributing impact on the Edwards Aquifer.The Edwards Aquifer contributing zones polygon file was created from modeled boundaries (2003 LIDAR) and customized boundaries based on contours, drainage infrastructure, COA Plans, and staff knowlege.

The Edwards and Trinity aquifers are major sources of water for agriculture, industry, and urban and rural communities in south-central Texas. Both the Edwards and Trinity aquifers are classified as major aquifers by the State of Texas. The dissolution of the carbonate rocks composing the Edwards and Trinity aquifers results in distinctive landforms rich in both springs and karst features (caves, sinkholes, and other visible areas of solution-enlarged porosity). Previous studies such as those by the U.S. Geological Survey (USGS) and the Texas Bureau of Economic Geology (BEG) have mapped the geology, hydrostratigraphy, and structure in these areas at various scales. The purpose of this data release is to present the data that were collected and compiled to describe the geologic framework and hydrostratigraphy of northern Bexar and Comal Counties, Texas in order to help water managers, water purveyors, and local residents better understand and manage water resources. The scope of the larger work and this accompanying data release is focused on the geologic framework and hydrostratigraphy of the outcrops and hydrostratigraphy of the Edwards and Trinity aquifers within northern Bexar and Comal Counties, Texas. In addition, parts of the adjacent upper confining unit to the Edwards aquifer are included. These digital data accompany Clark and others (2023), which supersedes Scientific Investigations Map 3366.

This raster data set delineates the predicted probability of elevated volatile organic compound (VOC) concentrations in groundwater in the Eagle River watershed valley-fill aquifer, Eagle County, North-Central Colorado, 2006-2007. This data set was developed by a cooperative project between the U.S. Geological Survey, Eagle County, the Eagle River Water and Sanitation District, the Town of Eagle, the Town of Gypsum, and the Upper Eagle Regional Water Authority. This project was designed to evaluate potential land-development effects on groundwater and surface-water resources so that informed land-use and water management decisions can be made. This groundwater probability map and its associated probability maps was developed as follows: (1) A point data set of wells with groundwater quality and groundwater age data was overlaid with thematic layers of anthropogenic (related to human activities) and hydrogeologic data by using a geographic information system to assign each well values for depth to groundwater, distance to major streams and canals, distance to gypsum beds, precipitation, soils, and well depth. These data then were downloaded to a statistical software package for analysis by logistic regression. (2) Statistical models predicting the probability of elevated nitrate concentrations, the probability of unmixed young water (using chlorofluorocarbon-11 concentrations and tritium activities), and the probability of elevated volatile organic compound concentrations were developed using logistic regression techniques. (3) The statistical models were entered into a GIS and the probability map was constructed.

This raster data set delineates the predicted probability of unmixed young groundwater (defined using chlorofluorocarbon-11 concentrations and tritium activities) in groundwater in the Eagle River watershed valley-fill aquifer, Eagle County, North-Central Colorado, 2006-2007. This data set was developed by a cooperative project between the U.S. Geological Survey, Eagle County, the Eagle River Water and Sanitation District, the Town of Eagle, the Town of Gypsum, and the Upper Eagle Regional Water Authority. This project was designed to evaluate potential land-development effects on groundwater and surface-water resources so that informed land-use and water management decisions can be made. This groundwater probability map and its associated probability maps were developed as follows: (1) A point data set of wells with groundwater quality and groundwater age data was overlaid with thematic layers of anthropogenic (related to human activities) and hydrogeologic data by using a geographic information system to assign each well values for depth to groundwater, distance to major streams and canals, distance to gypsum beds, precipitation, soils, and well depth. These data then were downloaded to a statistical software package for analysis by logistic regression. (2) Statistical models predicting the probability of elevated nitrate concentrations, the probability of unmixed young water (using chlorofluorocarbon-11 concentrations and tritium activities), and the probability of elevated volatile organic compound concentrations were developed using logistic regression techniques. (3) The statistical models were entered into a GIS and the probability map was constructed.

This raster data set delineates the predicted probability of elevated nitrate concentrations in groundwater in the Eagle River watershed valley-fill aquifer, Eagle County, North-Central Colorado, 2006-2007. This data set was developed by a cooperative project between the U.S. Geological Survey, Eagle County, the Eagle River Water and Sanitation District, the Town of Eagle, the Town of Gypsum, and the Upper Eagle Regional Water Authority. This project was designed to evaluate potential land-development effects on groundwater and surface-water resources so that informed land-use and water management decisions can be made. This groundwater probability map and its associated probability maps was developed as follows: (1) A point data set of wells with groundwater quality and groundwater age data was overlaid with thematic layers of anthropogenic (related to human activities) and hydrogeologic data by using a geographic information system to assign each well values for depth to groundwater, distance to major streams and canals, distance to gypsum beds, precipitation, soils, and well depth. These data then were downloaded to a statistical software package for analysis by logistic regression. (2) Statistical models predicting the probability of elevated nitrate concentrations, the probability of unmixed young water (using chlorofluorocarbon-11 concentrations and tritium activities), and the probability of elevated volatile organic compound concentrations were developed using logistic regression techniques. (3) The statistical models were entered into a GIS and the probability map was constructed.