WRIR 02-4030:
Streamflow and Water-Quality Data for Selected Watersheds in the Lake Tahoe Basin, California and Nevada, through September 1998

CONTENTS

INTRODUCTION

Background

Acknowledgments

Purpose and Scope

ENVIRONMENTAL SETTING

Subdivided Areas

Climate

Streamflow

Watershed-Drainage Information

Water-Quality Data

Field Measurements

Nutrients and Suspended Sediment

Nutrients and Suspended Sediment Load Estimation

ESTIMATOR Program

FLUX Program

Trend Calculations

Streamflow

Water-Quality Data

Field Measurements

Water Temperature

Specific Conductance

pH

Dissolved Oxygen

Nutrients and Suspended Sediment

Dissolved Nitrite Plus Nitrate Nitrogen

Dissolved Ammonia Nitrogen

Total Ammonia and Organic Nitrogen

Soluble Reactive Phosphorus

Total Phosphorus

Biologically Reactive Iron

Suspended Sediment

Concentration Versus Time and Flow

Load Estimations

Comparison of Nutrient and Suspended Sediment

Monthly Loads from Primary and Secondary Stations

Dissolved nitrite plus nitrate nitrogen

Dissolved ammonia nitrogen

Total nitrogen

Soluble reactive phosphorus

Total phosphorus

Biologically reactive iron

Suspended sediment

Index Station Monthly Loads

Incline Creek near Crystal Bay

Upper Truckee River at South Lake Tahoe

Watershed Load Comparison

Within-Watershed Station Load Comparisons

Yields and Ranks

Trends in Concentrations

REFERENCES CITED

APPENDICES

Appendix 1: Water-Quality and Streamflow Information on the Internet

Appendix 2: Estimated Nutrient and Suspended-Sediment Monthly Loads

FIGURES

List of Figures

TABLES

CONVERSION FACTORS AND VERTICAL DATUM


Multiply	By	To obtain

acre feet (acre-ft)	0.001233	cubic hectometer
cubic foot per second (ft³/s)	0.02832	cubic meter per second
foot (ft)	0.3048	meter
inch (in.)	25.4	millimeter
mile (mi)	1.609	kilometer
square mile (mi² )	2.590	square kilometer
kilogram (kg)	2.205	pounds (lbs)
kilogram per square kilometer (kg/km²)	5.712	pounds per square mile (lb/mi²)

Temperature: Degrees Celsius (°C) can be converted to degrees Fahrenheit (°F) by using the formula °F = [1.8(°C)] + 32. Degrees Fahrenheit can be converted to degrees Celsius by using the formula °C = 0.556(°F - 32).

Sea level: In this report, "sea level" refers to the National Geodetic Vertical Datum of 1929 (NGVD of 1929, formerly called "Sea-Level Datum of 1929"), which is derived from a general adjustment of the first-order leveling networks of the United States and Canada.

NOTE: U.S. Bureau of Reclamation datum for the surface-water elevation of Lake Tahoe is 1.14 feet higher than the NGVD of 1929.

Water-quality units:

micrograms per liter	µg/L
microsiemens per centimueter	µS/cm
milligrams per liter	mg/L
kilograms per month	kg/mo
kilograms per square kilometers per month	kg/km²/mo