Prepared in cooperation with the TAHOE REGIONAL PLANNING AGENCY Surface- and Ground-Water Characteristics in the Upper Truckee River and Trout Creek Watersheds, South Lake Tahoe, California and Nevada, July-December 1996 Water-Resources Investigations Report 00-4001 U.S. Department of the Interior U.S. Geological Survey U.S. Department of the Interior U.S. Geological Survey Surface- and Ground-Water Characteristics in the Upper Truckee River and Trout Creek Watersheds, South Lake Tahoe, California and Nevada, July-December 1996 By Timothy G. Rowe and Kip K. Allander Water-Resources Investigations Report 00-4001 Prepared in cooperation with the TAHOE REGIONAL PLANNING AGENCY Carson City, Nevada 2000 U.S. DEPARTMENT OF THE INTERIOR BRUCE BABBITT, Secretary U.S. GEOLOGICAL SURVEY CHARLES G. GROAT, Director Any use of trade names in this publication is for descriptive purposes only and does not constitute endorsement by the U.S. Government For additional information Copies of this report can be contact: purchased from: District Chief U.S. Geological Survey U.S. Geological Survey Branch of Information Services 333 West Nye Lane, Room 203 Box 25286 Carson City, NV 89706-0866 Denver, CO 80225-0286 email: [email protected] http://nevada.usgs.gov CONTENTS Abstract.................................................................................................................................................................................. 1 Introduction............................................................................................................................................................................ 2 Background ................................................................................................................................................................ 2 Purpose and Scope ..................................................................................................................................................... 4 Previous Studies......................................................................................................................................................... 4 Acknowledgments...................................................................................................................................................... 5 Description of Study Area ..................................................................................................................................................... 5 Geology...................................................................................................................................................................... 5 Vegetation................................................................................................................................................................... 7 Climate ....................................................................................................................................................................... 7 History........................................................................................................................................................................ 7 Upper Truckee River Watershed ................................................................................................................................ 7 Trout Creek Watershed............................................................................................................................................... 8 Inventory and Measurement Methods ................................................................................................................................... 8 Streamflow and Seepage............................................................................................................................................ 8 Wells and Ground-Water Levels ................................................................................................................................ 11 Water Quality ............................................................................................................................................................. 21 Surface- and Ground-Water Conditions ................................................................................................................................ 28 Streamflow and Seepage Estimates ........................................................................................................................... 28 Ground-Water Levels and Direction of Flow............................................................................................................. 30 Water Quality ............................................................................................................................................................. 33 Summary and Conclusions .................................................................................................................................................... 36 References Cited.................................................................................................................................................................... 38 PLATE [Plate is in pocket at back of report] 1. Map showing ground-water level contours and stream sections of gaining and losing flow in Upper Truckee River and Trout Creek watersheds, California and Nevada, August-November 1996 FIGURES 1-4. Maps of the Upper Truckee River and Trout Creek watersheds showing: 1. Lake Tahoe Basin, California and Nevada............................................................................................................ 3 2. Locations of roads, streams, and general surficial geology.................................................................................. 6 3. Streamflow measurement sites, September 1996. ................................................................................................ 15 4. Location of well sites and general surficial geology, September 1996................................................................. 20 5-6. Boxplots showing summary statistics for surface- and ground-water sites, July-December 1996, for: 5. Water-quality field measurements......................................................................................................................... 25 6. Nutrient concentrations......................................................................................................................................... 26 7. Hydrograph showing streamflow for the Upper Truckee River at South Lake Tahoe, California, and for Trout Creek near Tahoe Valley, California, and daily precipitation below Fallen Leaf Lake, California, 1996 water year.......................................................................................................................................................... 29 8. Graph showing cumulative streamflow gains and losses for Upper Truckee River and Trout Creek, California, September 1996 ......................................................................................................................................................... 30 9. Hydrographs showing water-level changes in wells 73 and 131 in Upper Truckee River and Trout Creek watersheds, California ............................................................................................................................................... 32 CONTENTS III 10-11. Graphs showing for sites on Upper Truckee River and Trout Creek, California: 10. Relation between distance from Lake Tahoe and specific conductance for surface-water-quality monitoring sites, September 1996. ................................................................................................................ 34 11. Field ground-water-quality measurements, July-December 1996.................................................................... 35 TABLES 1-7. Tables for Upper Truckee River and Trout Creek watersheds, California, listing: 1. Periods of record for daily streamflow, water-quality, and suspended sediment data at current and historical U.S. Geological Survey gaging stations and sampling sites.......................................................... 5 2. Streamflow measurement sites used for seepage estimates, September 1996......................................................9 3. Streamflow and water-quality data for streamflow sites, September 1996. ......................................................... 12 4. Streamflow measurement data and seepage estimates for designated main-stem reaches, September 1996....... 14 5. Selected characteristics of ground-water monitoring sites, July-November 1996................................................16 6. Water-quality data for selected streamflow sites, July-December 1996 ............................................................... 22 7. Water-quality data for ground-water monitoring sites, July-December 1996....................................................... 27 CONVERSION FACTORS, VERTICAL DATUM, AND ABBREVIATED WATER-QUALITY UNITS Multiply By To obtain cubic foot per second (ft3/s) 0.02832 cubic meter per second cubic foot per second per mile (ft3/s/mi) 0.01760 cubic meter per second per kilometer foot (ft) 0.3048 meter inch (in.) 25.4 millimeter mile (mi) 1.609 kilometer square mile (mi2) 2.590 square kilometer Temperature: Degrees Celsius (oC) can be converted to degrees Fahrenheit (oF) by using the formula oF = [1.8(oC)]+32. Degrees Fahrenheit can be converted to degrees