Groundwater and Springs

In 2016, the U.S. Geological Survey (USGS), in cooperation with the San Antonio Water System, began a study to refine previously derived estimates of groundwater outflows from Medina and Diversion Lakes in south-central Texas near San Antonio.

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 in Hays County, Texas are needed. In 2016 and 2018, the Oklahoma-Texas Water Science Center (OTWSC), in...

In 2014, USGS, in cooperation with Llano Estacado Underground Water Conservation District, Sandy Land Underground Water District, and South Plains Underground Water Conservation District, began a multiphase project to develop a regional conceptual model of the hydrogeologic framework and geochemistry of the Ogallala, Edwards-Trinity, and Dockum aquifers. The Ogallala aquifer is the shallowest...

In cooperation with Harris-Galveston Subsidence District, the City of Houston, Fort Bend County Subsidence District, Lone Star Groundwater Conservation District, and Brazoria County Groundwater Conservation District, the USGS Oklahoma-Texas Water Science Center Gulf Coast Program collects, processes, and interprets groundwater-level and aquifer-sediment-compaction data to understand the effects of...

The USGS Oklahoma-Texas Water Science Center (OTWSC) is testing the suitability of seismic refraction tomography (SRT) and time-domain electromagnetic sounding (TDEM) geophysical methods for mapping the contact boundary between the Granite Gravel aquifer and the underlying crystalline Town Mountain Granite bedrock in southwestern Burnet County. The Granite Gravel aquifer is anticipated to show a...

The USGS Oklahoma-Texas Water Science Center is implementing a more complete and integrated monitoring network for the Edwards aquifer to improve the understanding of aquifer water quality and establish a baseline for measuring future water-quality changes.

USGS Oklahoma-Texas Water Science Center (OTWSC) is undertaking a 1.5-year study to assess parameter and predictive uncertainty in the Edwards Aquifer Authority MODFLOW Model using both linear and non-linear techniques. The Edwards Aquifer Authority (EAA) uses two models simulating the periods from 2001 to 2015 (verification model) and the drought of record of 1947-1958 (drought of record model).

USGS is undertaking a 5-year study to assess groundwater availability for the aquifers proximal to the Gulf of America from the Texas-Mexico border through the panhandle of Florida, known as the Coastal Lowlands Aquifer System (CLAS). This study is one of several within the Regional Groundwater Availability Studies of the USGS Water Availability and Use Science Program.

Surface-water/groundwater interactions include the exchange of water, and the chemicals that may be present in the water, which can lead to issues with water supply and water quality. Groundwater can be a major contributor to streams, lakes, and wetlands while surface water can contribute recharge to groundwater. The USGS Oklahoma-Texas Water Science Center (OTWSC) uses geophysics and other...

The USGS Oklahoma-Texas Water Science Center (OTWSC) has researched land-surface subsidence for more than 40 years. OTWSC collects and interprets groundwater level and aquifer sediment compaction data to understand the effects of groundwater withdrawal on land surface subsidence.

Hydrogeology is the study of how groundwater moves and is distributed. At the USGS Oklahoma-Texas Water Science Center (OTWSC), hydrogeologic studies focus on regional groundwater assessments, focused investigations, aquifer delineation, and inter-agency science support.

The Edwards aquifer in south-central Texas is one of the most productive aquifers in the Nation and is the primary source of water for the rapidly growing San Antonio area. Springs issuing from the Edwards aquifer provide habitat for several threatened and endangered species, serve as locations for recreational activities, and supply downstream users. The USGS Oklahoma-Texas Water Science Center...