Publications

Water-chemistry data from the Edwards aquifer for 1976-85, consisting of nearly 1,500 chemical analyses from 280 wells and 3 springs, were used to statistically evaluate relations among ground-water chemistry, hydrogeology, and land use. Five land uses associated with sampled wells were classified on the basis of published information and field surveys. Four major subareas of the aquifer...

This report contains summary information on ground-water quality in one of the 50 States, Puerto Rico, the Virgin Islands, or the Trust Territories of the Pacific Islands, Saipan, Guam, and American Samoa. The material is extracted from the manuscript of the 1986 National Water Summary, and with the exception of the illustrations, which will be reproduced in multi-color in the 1986...

The Edwards aquifer is a complexly faulted, carbonate aquifer lying within the Balcones fault zone of south-central Texas. The aquifer is recharged mainly by streamflow losses in the outcrop area of the Edwards aquifer and is discharged by major springs located at considerable distances, as much as 150 mi, from the areas of recharge, and by wells. Groundwater flow within the Edwards...

This report updates ground-water information pertaining to the lower unit of the Chicot aquifer in the Orange County area, Texas and Louisiana. The period of data collection was from 1980 to the spring of 1985. Some data collected prior to 1980 are presented to establish long-term trends and relations. The lower unit of the Chicot aquifer, which consists of sediments of Pleistocene age...

Hydrologic investigations of urban watersheds in Texas were begun by the U.S. Geological Survey in 1954. Studies are now in progress in Austin, and Houston. Studies have been completed in the Dallas, Fort Worth, and San Antonio areas. The Geological Survey, in cooperation with the Texas Department of Water Reources, began hydrologic studies in the Austin urban area in 1954. In...

Hydrologic Accounting Unit 120301 is located in north-central Texas and includes that part of the Trinity River basin upstream from the National Stream Quality Accounting Network station 08062700, Trinity River at Trinidad, Texas. Normal annual precipitation ranges from about 28 inches in the western part of the basin to almost 40 inches in the eastern part. The population of the upper...

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...

Most of the water needs of Tom Green County, Texas, are supplied by ground water; however, the city of San Angelo is supplied by surface water. Groundwater withdrawals during 1980 (latest year for which data are available) in Tom Green County totaled about 15,300 acre-feet, all derived from shallow aquifers. Shallow aquifers in this report refer to the ground-water system generally less...

The salinity front, locally known as the "bad-water" line, in the Edwards aquifer separates the freshwater from the salinewater and occurs where the aquifer is confined. The concentration of dissolved solids of the salinewater at the salinity front is 1,000 milligrams per liter. The concentration of dissolved solids in water within the freshwater zone of the aquifer usually ranges from...

As of January 1, 1986, the surface-water data-collection network in Texas operated by the U.S. Geological Survey included 386 streamflow, 87 reservoir-contents, 33 stage, 10 crest-stage partial-record, 8 periodic discharge through range, 38 flood-hydrograph partial-record, 11 flood-profile partial-record , 36 low-flow partial-record 2 tide-level, 45 daily chemical-quality, 23 continuous...

No abstract available.

Twenty-seven geohydrology sections illustrate structural and stratigraphic relationships within the 180-mi-long Edwards aquifer. These sections were used to interpret the location of barriers within the Edwards aquifer. The sections are oriented generally south-southeast, which is approximately normal to both the east-northeast trending Edwards aquifer and the strike of the major faults...