U.S. Geological Survey Fact Sheet 2005-3047
PDF (Portable Document Format) File: FS2005-3047.pdf (811 kb)
Lake Tahoe is famous for its alpine setting and deep, clear water. Over the last half century, clarity has declined by 30–40 feet or 1 foot per year. This decline in clarity has been attributed, in part, to nutrients and sediments delivered to the lake by its tributary streams and nutrients from ground-water inflow.
For decades, the U.S. Geological Survey (USGS) has been involved with a wide range of scientific research and monitoring activities in the Lake Tahoe Basin. Water-related activities include stream quantity and quality, ground-water levels and quality, and lake levels and quality. Mapping activities include topographic, bathymetric, and geologic; land-cover and land-use change delineation; and socioeconomic modeling.
The USGS Water Science Centers in Nevada (NWSC) and California (CWSC), Geology and Geography Disciplines, in cooperation with Federal, State and local agencies, are involved with the following:
Tahoe Decision Support System: The Tahoe Decision Support System (TDSS) tool is being developed to assist the Tahoe Regional Planning Agency (TRPA) with estimating the effects of policy decisions on local economic and environmental health.
Land-Cover Characterization: A land-cover characterization study is being completed as part of a Nationwide study. The land-cover dataset includes information from LandSat satellites as well as many other sources such as census statistics.
Stream Monitoring: Nutrient, suspended-sediment, water-quality, and streamflow data are currently collected at 20 sites, in cooperation with TRPA and the University of California, Davis, and as part of the Lake Tahoe Interagency Monitoring Program (LTIMP). Runoff from the Gondola Fire area also is being monitored. These data are used to provide a consistent, long-term database and to identify trends throughout the Basin. Data are stored in the National Water Information System (NWIS) and are compiled annually.
Ground-Water Monitoring: Shallow ground-water in South Lake Tahoe is being studied to determine potential transport of contaminants. A ground-water study in the Bijou Creek area of South Lake Tahoe was recently completed as was a ground-water/surface-water interaction study in the Trout Creek area. Data from these studies are stored in NWIS and are compiled annually.
Cattlemans Detention Basin Effectiveness: The effects on ground-water quality and levels from the construction and operation of a stormwater detention basin along Cold Creek are being examined in partnership with El Dorado County, Calif. This project includes examining geochemical processes affecting water quality and using a numerical ground-water flow model to analyze ground-water/
Tim Rowe, USGS Hydrologist, presents results from a USGS study at Lake Tahoe. Photograph by M.L. Strobel, May 2004.
|AccessibilityFOIAPrivacyPolicies and Notices|