Publications

Rapid development and population growth are occurring in Webb County in south Texas (fig. 1). Water managers need information on the ground-water resources of the area to address the increased demand for water caused by the development. To help meet this need, the U.S. Geological Survey (USGS), in cooperation with the City of Laredo, began a study in 1997 to assess the ground-water...

No abstract available.

Severe flooding in parts of south-central Texas resulted from a major storm during October 17–18, 1998. The flooding occurred in parts of the major streams and tributaries of the San Jacinto, San Benard, Colorado, Lavaca, Guadalupe, and San Antonio River Basins. Peak gage height, peak streamflow, and documentation of the significance of the peaks were compiled for the streamflow-gaging...

No abstract available.

Many contaminants introduced into the environment by human activities are hydrophobic, meaning they are relatively insoluble in water and, thus, are associated primarily with sediments. These contaminants include the organochlorine pesticides DOT and chlordane, polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) from industrial facilities and urban areas, and...

Water-resources data for the 1998 water year for Texas are presented in four volumes, and consist of records of stage, discharge, and water quality of streams and canals; stage, contents, and water quality of lakes and reservoirs; and water levels and water quality of ground-water wells. Volume 2 contains records for water discharge at 74 gaging stations; stage only at 9 gaging stations...

The lower unit of the Chicot aquifer is a major source of freshwater for Orange County, Texas. In 1989, the average rate of ground-water withdrawal from the lower unit of the Chicot aquifer in Orange County for municipal and industrial use was 13.8 million gallons per day, a substantial decrease from the historical high of 23.1 million gallons per day in 1972. The average withdrawal for...

The reduction of the precipitation depth from a design storm for a point to an effective (mean) depth over a watershed often is important for cost-effective design of hydraulic structures by reducing the volume of precipitation. A design storm for a point is the depth of precipitation that has a specified duration and frequency (recurrence interval). The effective depth can be calculated...

Historical use of pesticides and rapid urbanization have left their mark on the chemistry of bottom sediments in Lorence Creek Lake (fig. 1) in the northern part of San Antonio, Tex. Several metals, organochlorine compounds (pesticides and polychlorinated biphenyls [PCBs]), and polycyclic aromatic hydrocarbons (PAHs) detected in bottom sediments of the lake have temporal trends...

Water-resources data for the 1998 water year for Texas are presented in four volumes, and consist of records of stage, discharge, and water quality of streams and canals; stage, contents, and water-quality of lakes and reservoirs; and water levels and water quality of ground-water wells. Volume 1 contains records for water discharge at 112 gaging stations; stage only at 5 gaging stations...

The hydrogeologic subdivisions of the Edwards aquifer outcrop in the Medina Lake area in Medina and Bandera Counties generally are porous and permeable. The most porous and permeable appear to be hydrogeologic subdivision VI, the Kirschberg evaporite member of the Kainer Formation; and hydrogeologic subdivision III, the leached and collapsed members, undivided, of the Person Formation...

Slug tests were used to characterize hydraulic conductivity variations at a spatial scale on the order of meters in the alluvial aquifer downgradient of the Norman Landfill. Forty hydraulic conductivity measurements were made, most along a 215-meter flow path transect. Measured hydraulic conductivity, excluding clayey layers, ranged from 8.4 x 10-7 to 2.8 x 10-4 meters per second, with a...