Diana L. Slagle | USGS Science

USGS1987

Hydrologic and geologic data for the Edwards Aquifer Recharge Zone near Georgetown, Williamson County, Texas, 1986-87

This report presents a compilation and summary of data related to the interchange of water between the Edwards aquifer and streams, and to the hydraulics of vertical movement of water in the Georgetown Limestone in the Georgetown area of Williamson County. It presents hydrologic, geologic, hydraulic, physical, geophysical, and water-quality data collected from selected wells and stream sites in the study area from January 1986 to June 1987. Included are the results from six streamflow gain and loss surveys, two ground-water-level surveys representing low and high water-level conditions, inorganic chemical analyses of water from selected wells and streams, and bulk specific gravity and permeability tests of cores taken at three test-well sites. Water-level altitudes differed by an average of 38 feet between low and high water-level conditions in the confined zone, and by an average of 13 feet in the unconfined zone. Dissolved solids of water from selected wells ranged from 320 to 1,300 milligrams per liter and from 251 to 290 milligrams per liter in water from selected streams.

Open-File Report↗

USGS1986

Recharge zone of the Edwards aquifer hydrologically associated with Barton springs in the Austin area, Texas

The Edwards aquifer extends in a narrow belt from Bell County in the northeast to Kinney County in the southwest (index map) and provides water for at least nine counties in south-central Texas. Hydrologic boundaries divide the Edwards aquifer in the Austin area for which Barton Springs is the major discharge point. This part of the Edwards aquifer provides the municipal, industrial, domestic, and agricultural water supplies for about 30,000 people in the Austin area (southern Travis and northern Hays counties). Discharge from Barton Springs sustains streamflow at the mouth of Barton Creek and flows into Town Lake. Much of the land use within the outcrop area of the Edwards aquifer near Austin is rapidly changing from natural woodland and grassland to commercial and residential developments. Because urban development can result in a substantial degradation of the quality of water that recharges the aquifer, the extent of the recharge zone of the Edwards aquifer was delineated to provide information to the City of Austin for their use in formulating a plan for protecting and managing groundwater quality. The purpose of this report is to define and delineate the areal extent of the recharge zone of the Edwards aquifer in southern Travis and northern Hays Counties. The areal boundary of the recharge zone was determined by: (1) geologic mapping of the aquifer area; (2) interpretation of aerial photographs; (3) field verification of existing geologic maps; and (4) streamflow-loss studies.

Water-Resources Investigations Report↗