In the 2012 President's Budget Request, the National Biological Information Infrastructure (NBII) is terminated. As a result, all resources, databases, tools, and applications within this web site will be removed on January 15, 2012. For more information, please refer to the NBII Program Termination page.
Explore CSWGCIN's Karst Mapping Application, with data layers for Groundwater and Surface Water Quality and Quantity, Critical Habitat for the Karst Threatened and Endangered Species, Precipitation data and more. The mapping application works with the ArcGIS Viewer for Flex. Click on the image of each of the Edwards, Ozarks, or Roswell aquifers to access the mapping application.
The Major Aquifers in Texas; map created by the Houston Advanced Research Center.
The Edwards Aquifer covers about 4530 square miles in parts of 11 counties in Texas. Edwards is the focus of this study due to its unique physical nature as a karst aquifer resulting in highly sensitive environmental areas that provide habitat to fourteen different threatened and endangered species. Water from the aquifer is used for municipal, irrigation and recreational purposes; 54% of this amount is for municipal purposes.
The Edwards Aquifer is comprised mainly of limestone; over time as groundwater has moved through the system, erosion of the limestone has caused a great deal of porous zones, leading to the cavernous nature of the aquifer. These caves and natural springs honeycombed throughout the aquifer provided small habitats that are ecologically unique. Due to being specialized niches, they are also extremely vulnerable to changes in groundwater or surface water conditions. The high permeability in Edwards Aquifer means it responds quite quickly to changes in precipitation; during times of below average rainfall or drought, conditions in the springs or caverns can quickly be reduced to environmentally detrimental levels. The following pages discuss the variety of threatened and endangered species in the aquifer, and highlight changes in precipitation and surface water and groundwater quality and quantity in the Edwards Aquifer.
Edwards Geo-Referenced Spatial Data
Choose from the spatial layer files below for download. The data include Edwards water quality, threatened and endangered species critical habitat, and sampling station and gauge locations. All data available for download were used in the creation of the spatial data for the Edwards Aquifer portal. The files are available for download as easy-to-use ESRI layer packages, compatible with ArcGIS 9.3.1.
After downloading, double-click the file and specify an output location to unpack the files. The data will then be added, fully symbolized, to ArcMap. For more information about layer packages, click here. Please contact Stephanie Glenn at firstname.lastname@example.org for information about obtaining GIS data compatible with older versions of ArcGIS.
Groundwater Quality Data Source: Texas Water Development Board