Mapping Brackish Groundwater in Aquifers of the Upper Coastal Plains, Central Texas

 Andrea Croskrey

The Brackish Resources Aquifer Characterization System (BRACS) program of the Texas Water Development Board is mapping brackish aquifers to better understand water resources in the state. The aquifers in this study include, from oldest to youngest, the Wilcox, Carrizo, Queen City, Sparta, and Yegua. Data mining and mapping the stratigraphy and lithology of aquifers was completed before salinity mapping started. Over 5,000 well records were appended to the BRACS database to achieve the goals of this study. Public water quality measurements from existing wells occur in the outcrop and less saline portions of the aquifers. Estimating TDS from resistivity logs allowed us to map the vertical and downdip variability in salinity where there were no measured water quality samples. Upon completion, all data related to the “Brackish Groundwater in Aquifers of the Upper Coastal Plains, Central Texas” study will be available at: http://www.twdb.texas.gov/innovativewater/bracs/index.asp.

Andrea Croskrey is a licensed professional geologist at the Texas Water Development Board. She has been mapping brackish aquifers and writing publications as a member of the agency’s Brackish Resources Aquifer Characterization System (BRACS) since 2013. Andrea earned a Bachelor of Science in Comprehensive Geology from Northwest Missouri State University and a Master of Science in Geosciences from Western Kentucky University.