Hydrogeology

San Antonio Texas consistently ranks as one of the fastest growing large cities in the United States. Urban development can affect groundwater quality as trees and open space are replaced by buildings and roads, increasing the amount of urban runoff draining directly into the Edwards aquifer. A network of sophisticated surface water and groundwater monitoring sites is being used to help managers...

Suspended sediment and nutrients from greater San Antonio can affect instream ecological health of the San Antonio River and ultimately impact Gulf of Mexico bays and estuaries. Real-time monitoring in urban and rural parts of the river basin may provide a glimpse into the importance of urban sediment and nutrient sources. Real-time sensors provide a tool to better understand and manage water...

The USGS National Water-Quality Assessment (NAWQA) Project was established by Congress in 1992 to answer the following question: What is the status of the Nation’s water quality and is it getting better or worse? Since 1992, NAWQA has been a primary source of nationally consistent data and information on the quality of the Nation’s streams and groundwater. Data and information obtained from...

The Texas Geology Web Map Viewer is the third generation in a series of Texas geologic mapping products intended to empower and expose this data to a broad range of diverse users interested in exploring the geology of the State of Texas.

USGS is undertaking a 3-year study of water use, availability, and change in the Upper Rio Grande Basin in one of several national “Focus Area Studies” in the Department of Interior’s WaterSMART initiative . The Upper Rio Grande study area runs 670 miles from its headwaters in Colorado through New Mexico and northern Mexico to Ft. Quitman, Texas. Along its river corridor, it is a primary source of...

The effects of urbanization across the recharge zone in Bexar County and potential impact on the water quality in the Edwards aquifer is a topic of specific concern for the City of San Antonio. The USGS Texas Water Science Center is simultaneously collecting water-quality data from surface-water runoff sites and paired shallow groundwater wells within the recharge zone of the Edwards aquifer to...

Many communities along the U.S.-Mexico border have limited surface water supply and rely on transboundary aquifers for industry, agriculture, and drinking water; however, information on water needs, water quality, and the extent and functioning of these aquifers is incomplete. The Transboundary Aquifer Assessment Program (TAAP), established through a binational agreement between the United States...

The USGS is undertaking a 3-year study of water use, availability, and change in the Red River basin in one of several national “Focus Area Studies” in the Department of Interior’s WaterSMART initiative . The Red River basin covers more than 93,000 square miles in New Mexico, Texas, Oklahoma, Arkansas, and Louisiana with a population of about 4.3 million people. Water resources in the basin are...

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 Texas Water Science Center (TXWSC), in cooperation...

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 Texas Water Science Center (TXWSC) 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 contrast...