Publications

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During 2000–2001, rainfall and runoff were monitored in one mixed agricultural watershed and two rangeland watersheds in San Patricio County, located in the Coastal Bend area of South Texas. During this period, five rainfall samples were collected and analyzed for selected nutrients. Ten runoff samples from nine runoff events were collected at the three watershed monitoring stations...

In November 1997, the U.S. Geological Survey, in cooperation with the City of Houston Utilities Planning Section and the City of Houston Department of Public Works & Engineering, began an investigation of the Chicot and Evangeline aquifers in the greater Houston area in Texas to better understand the hydrology, flow, and associated land-surface subsidence. The principal part of the...

The Arroyo Colorado, an ancient channel of the Rio Grande, extends 90 miles from Mission, Tex., to the Laguna Madre. The Arroyo Colorado flows through areas of intense agricultural cultivation and through important habitat for migrating birds and other wildlife, including several wildlife sanctuaries and refuges. The above-tidal segment of the Arroyo Colorado is included in the State of...

The Bromide Pavilion in Chickasaw National Recreation Area drew many thousands of people annually to drink the mineral-rich waters piped from nearby Bromide and Medicine Springs. Periodic detection of fecal coliform bacteria in water piped to the pavilion from the springs, low yields of the springs, or flooding by adjacent Rock Creek prompted National Park Service officials to...

During 1999–2001, the U.S. Geological Survey, in cooperation with the Texas Natural Resource Conservation Commission, collected samples of untreated water from 48 public water-supply reservoirs and 174 public water-supply wells. The samples were analyzed for volatile organic compounds (VOCs) and soluble pesticides; in addition, well samples were analyzed for nitrite plus nitrate and...

Water-quality trends were assessed in Lake Houston using age-dated sediment cores. Sediments deposited in the lake contain a partial chemical signature of human activities in the watershed. Over time, a water-quality history is recorded in the bottom sediments. Although the sediments in Lake Houston are clean compared to sediment-quality guidelines, increasing concentrations of mercury...

Since 1991, the U.S. Geological Survey (USGS) National Water-Quality Assessment (NAWQA) Program has collected pesticide data from streams and aquifers throughout the Nation (Gilliom and others, 1995). However, little published information on pesticides in public drinking water is available. The NAWQA Program usually collects data on the sources of drinking water but not on the finished...

A model parameter set for use with the Hydrological Simulation Program—FORTRAN watershed model was developed to simulate flow and water quality for selected properties and constituents for the Arroyo Colorado from the city of Mission to the Laguna Madre, Texas. The model simulates flow, selected water-quality properties, and constituent concentrations. The model can be used to estimate a...

The Christmas Bay system is a group of three small secondary bays (Christmas, Bastrop, and Drum Bays) at the southwestern end of the Galveston Bay estuarine system in Brazoria County, Texas. During February 1999-March 2000, hydrologic, water-quality, and sediment-quality data were collected from each of the three bays to establish baseline conditions. Gage-height fluctuations closely...

Some fish in the Donna Canal contain PCBs at levels that might pose a risk to human health if the fish are eaten. Early attempts to locate the source of PCBs in the canal were unsuccessful. An innovative method of sampling and analyzing suspended sediment helped scientists detect PCBs in suspended sediment and narrowed the probable PCB source area(s) from the entire 11-kilometer canal to...

Five streamflow gain-loss measurement surveys were made along lower San Pedro Creek and the San Antonio River from Mitchell Street to South Loop 410 east of Kelly Air Force Base in San Antonio, Texas, during May–October 1999. All of the measurements were made during dry periods, when stormwater runoff was not occurring and effects of possible bank storage were minimized. San Pedro Creek...