GEOHYDROLOGIC MAPPING OF THE EDWARDS AQUIFER RECHARGE ZONE IN KINNEY AND MEDINA COUNTIES, SOUTH-CENTRAL TEXAS
Rock formations, sinkholes, exposed collapse structures, mafic igneous bosses and dikes, and east-northeast-trending normal faults are shown in the Balcones Fault Zone and adjacent areas north and south. The map provides information to help evaluate recharge potential, storage and flow-pathway development, and to aid ongoing 3-D geologic and ground-water modeling efforts. Pantea's work includes 3-D models of the recharge zone in a part of Medina County. The models utilize well data, helicopter electromagnetic surveys, and detailed geologic mapping. The models are interactive, rotatable computer 3-D images of plausible geologic interpretations.
Investor-backed development interests have publicized estimates of annual recharge of the aquifer in Kinney County that significantly differ from those of a local governmental agency which regulates the long-term usage of the aquifer. Differing interpretations of sustainable yield will need to be compared and debated to support approval/denial of specific aquifer-development plans. Ground-water modeling based on detailed geologic maps and hydrologic studies provides more objective estimates of aquifer storage, leading to more credible predictions of sustainable groundwater development.