National Water-Quality Assessment Program (NAWQA)

The Nevada Basin and Range (NVBR) study unit includes three hydrographic basins and adjacent areas: (1) the Las Vegas Valley area, (2) the Carson River Basin, and (3) the Truckee River Basin. The Las Vegas Valley area is in southern Nevada and the Carson and Truckee River Basins are in northwestern Nevada and northeastern California. The basins were selected for investigation because they (1) contain more than 90 percent of Nevada's population; (2) include geologic features, climate, vegetation, and hydrology representative of Basin and Range physiography; (3) include areas where rapid urban and suburban population growth has increased competition for limited water supplies; and (4) contain various natural- and human-caused water-quality problems.

During Cycle 1 of NAWQA (1991-2000), most of the program's emphasis was on characterizing the status of water quality. During Cycle II, most of the program's emphasis will be on trends and understanding factors that affect water quality. To describe trends, surface-water sites that have been monitored since Cycle I will continue to be monitored. Sub-unit surveys and land-use surveys will be re-sampled to characterize decadal changes in ground-water quality. In addition, lakes and reservoirs will be cored to characterize trends in the deposition of hydrophobic contaminants. The goal of understanding will focus on 2 topics that are important in the NVBR study unit: contaminant transport to public supply wells and effects of urbanization on streams. An extra year of intensive data collection is planned for the first group of Cycle II study units to develop approaches for these topics. Status and trends work will be front-loaded in the first two years of Cycle II, and topics will be worked on during the remaining years of the high-intensity phase.

National NAWQA Program

The NAWQA Program of the USGS is the primary source of long-term, nationwide information on the quality of streams, ground water, and aquatic ecosystems. In more than 50 major river basins and aquifers across the nation, USGS scientists collect and assess information on water chemistry, hydrology, land use, stream habitat, and aquatic life.

Program Details National Synthesis Data Warehouse Digital Map Products Glossary

For Further Information on the NAWQA Program: Michael Rosen, Ph.D. Project Chief USGS 333 W. Nye Lane Carson City, NV 89706 (775) 887-7683 Email: mrosen@usgs.gov

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U.S. Department of the Interior, U.S. Geological Survey
Contact: Nevada District Web Team
Last Modified: July 30, 2003
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