Publications

Four recharge tests were conducted by injecting water from playa lakes through wells into the Ogallala Formation. Injection was by gravity flow and by pumping under pressure. At one site, 34-acre feet of water was injected by gravity and produced a significant increase in yield of the well. At a second site, gravity injection of only 0.58 acre-foot caused a significant decrease in...

Thermal stratification in Lake Conroe, Texas usually begins to develop in March and persists until October. Thermal stratification has resulted in significant seasonal and areal variations in the concentrations of dissolved oxygen, dissolved iron, dissolved manganese, total inorganic nitrogen, and total phosphorus. Volume-weighted-average concentration of dissolved solids generally was ...

The average annual ground-water recharge to the Edwards aquifer in the San Antonio area, Texas, from 1934 through 1981, was 612,400 acre-feet. The recharge in 1981 was 1,448,400 acre-feet, which is the third highest annual recharge since 1934. A maximum annual recharge of 1,711,200 acre-feet occurred in 1958, and a minimum annual recharge of 43,700 acre-feet occurred in 1956. The...

Fresh to slightly saline water is available in most parts of Rusk County, which is located in the Piney Woods region of northeast Texas. The Wilcox aquifer, which underlies the entire county, was the source of most of the ground water withdrawn during 1980. Other units capable of yielding fresh ground water are the Carrizo, Queen City, and Sparta aquifers and the Reklaw Formation. About...

Limestone County, located in east-central Texas, has small to plentiful ground-water supplies available, depending upon the location within the county. The Wilcox Group in the eastern part of the county has adequate supplies to meet the expected water demands in the foreseeable future. The thicker zones of the Wilcox Group can supply yields in excess of 500 gallons per minute. The Midway...

Regional differences in the porosity and permeability of the Edwards aquiifer are related to three major depositional areas, the Maverick basin the Devils River trend, and the San Marcos platform, that existed during Early Cretaceous time. The rocks of the Maverick basin are predominantly deep basinal deposits of dense, homogeneous mudstones of low primary porosity. Permeability is...

The U.S. Geological Survey's investigations of the water resources of Texas are conducted in cooperation with the Texas Department of Water Resources, river authorities, cities, counties, U.S. Army Corps of Engineers, U.S. Bureau of Reclamation, International Boundary and Water Commission, and others. Investigations are under the general direction of C. W. Boning, District Chief, Texas...

This map report is one of a series of geologic and hydrologic maps of States in the Basin and Range Province. These map reports contain information on ground-water hydrology, ground-water quality, surface distribution of selected rock types, data on tectonic conditions, areal geophysical data, Pleistocene lakes and marshes and natural resources. This information is the basis for a...

No abstract available.

Geological contacts were picked on logs of about 480 wells in the San Antonio area of the Edwards aquifer. The base of the Del Rio Clay is the most frequently picked contact because it is the top of the Edwards aquifer and also because it is easily identified on either gamma-ray or electric logs. Other important formation contacts identified were the Austin Group, the Eagle Ford Group...

The importance of the Edwards aquifer as a freshwater resource and its susceptibility to being contaminated, being over utilized, or both resulted in the development of a proposed 10-year plan to monitor and study its hydrology. The plan proposes adjustments to the current monitoring activities of computing and measuring recharge, discharge, withdrawals, water levels, and water quality...

No abstract available.