Streamflow and Water-Quality Data for Selected Watersheds in the Lake Tahoe Basin, California and Nevada, Through September 1998 By Timothy G. Rowe1, Dina K. Saleh2, Sharon A. Watkins1, and Charles R. Kratzer3 1 U.S. Geological Survey, Carson City, Nevada. 2 California State University, Sacramento, California. 3 U.S. Geological Survey, Sacramento, California. U.S. GEOLOGICAL SURVEY Water-Resources Investigations Report 02-4030 Prepared in cooperation with the LAHONTAN REGIONAL WATER QUALITY CONTROL BOARD TAHOE REGIONAL PLANNING AGENCY UNIVERSITY OF CALIFORNIA, DAVIS Carson City, Nevada 2002 Cover photograph: Incline Creek inflow to Lake Tahoe, looking south from mouth near Incline Village, Nev., June 1999. Photograph by Timothy G. Rowe, U.S. Geological Survey. U.S. DEPARTMENT OF THE INTERIOR GALE A. NORTON, Secretary U.S. GEOLOGICAL SURVEY CHARLES G. GROAT, Director Any use of trade, product, or firm names in this publication is for descriptive purposes only and does not imply endorsement by the U.S. Government. All World Wide Web links that appear in this document were current only at the time of publication and are not maintained. For additional information contact: District Chief U.S. Geological Survey 333 West Nye Lane, Room 203 Carson City, NV 89706–0866 email: [email protected] home page: http://nevada.usgs.gov CONTENTS ABSTRACT........................................................................................................................................................................... 1 INTRODUCTION ................................................................................................................................................................. 2 Background ................................................................................................................................................................ 2 Acknowledgements .................................................................................................................................................... 2 Purpose and Scope ..................................................................................................................................................... 8 ENVIRONMENTAL SETTING ........................................................................................................................................... 8 Subdivided Areas ....................................................................................................................................................... 8 Climate ....................................................................................................................................................................... 12 METHODS............................................................................................................................................................................ 18 Streamflow ................................................................................................................................................................. 18 Watershed-Drainage Information............................................................................................................................... 18 Water-Quality Data..................................................................................................................................................... 18 Field Measurements........................................................................................................................................ 18 Nutrients and Suspended Sediment ................................................................................................................ 18 Nutrient and Suspended-Sediment Load Estimation ................................................................................................. 19 ESTIMATOR Program ................................................................................................................................... 19 FLUX Program ............................................................................................................................................... 19 Trend Calculations ..................................................................................................................................................... 20 RESULTS .............................................................................................................................................................................. 20 Streamflow ................................................................................................................................................................. 20 Water-Quality Data..................................................................................................................................................... 29 Field Measurements........................................................................................................................................ 29 Water Temperature .............................................................................................................................. 29 Specific Conductance.......................................................................................................................... 29 pH........................................................................................................................................................ 29 Dissolved Oxygen ............................................................................................................................... 29 Nutrients and Suspended Sediment ................................................................................................................ 41 Dissolved Nitrite Plus Nitrate Nirtogen .............................................................................................. 41 Dissolved Ammonia Nitrogen............................................................................................................. 41 Total Ammonia and Organic Nitrogen................................................................................................ 41 Soluble Reactive Phosphorus.............................................................................................................. 41 Total Phosphorus................................................................................................................................. 41 Biologically Reactive Iron .................................................................................................................. 52 Suspended Sediment ........................................................................................................................... 52 ConcentrationVersus Time and Streamflow........................................................................................ 52 Load Estimations ............................................................................................................................................ 52 Comparison of Nutrient and Suspended-Sediment Load Estimations................................................ 52 Monthly Loads from Primary and Secondary Stations....................................................................... 52 Dissolved nitrite plus nitrate nitrogen ..................................................................................... 65 Dissolved ammonia nitrogen ................................................................................................... 65 Total nitrogen........................................................................................................................... 65 Soluble reactive phosphorus.................................................................................................... 65 Total phosphorus...................................................................................................................... 65 Biologically reactive iron ........................................................................................................ 65 Suspended sediment ................................................................................................................ 65 Index Station Monthly Loads.............................................................................................................. 65 Incline Creek near Crystal Bay................................................................................................ 75 Upper Truckee River at South Lake Tahoe.............................................................................. 75 Watershed-Load Comparison.............................................................................................................. 75 Within-Watershed Station Load Comparisons.................................................................................... 75 Yields and Ranks................................................................................................................................. 89 CONTENTS III Primary Stations.................................................................................................................................. 94 Within-Watershed Stations.................................................................................................................. 94 Trends in Concentrations................................................................................................................................ 94 SUMMARY..........................................................................................................................................................................