TABLE OF CONTENTS 



PART I 



Page 



FOREWORD 5 



LETTER OF TRANSMITTAL 15 



ACKNOWLEDGMENT 16 



ORGANIZATION, STATE DEPARTMENT OF PUBLIC WORKS 17 



ORGANIZATION, UNITED STATES DEPARTMENT OF AGRICULTURE 18 



Chapter I 



INTRODUCTION AND SUMMARY 19 



Introduction 19 



Summary 20 



Santa Ana, Prado, and San Bernardino Stations 20 



Victorville Station 23 



Coldwater Canyon Investigations 24 



Evaporation from free water surfaces 25 



Chapter II 



INVESTIGATIONS IN THE SANTA ANA RIVER VALLEY AND COASTAL 



PLAIN 26 



Santa Ana Station 26 



Description of site 26 



Station equipment 28 



Method of filling soil tanks 29 



The Mariotte tank 30 



San Bernardino Station 32 



Description of site 32 



Station equipment 33 



Prado Station 34 



Description of site 34 



Station equipment 34 



Meteorological records 35 



Operation of tanks 40 



Sources of errors in tank experiments 40 



Santa Ana Station 41 



San Bernardino Station 45 



Prado Station — 45 



Protection from rainfall 45 



Soil alkali in tanks 47 



Consumptive use of water 49 



Evaporation from soil surfaces in tanks 49 



Use of water by salt grass — 50 



Use of water by Bermuda grass 53 



Use of water by tules and cat-tails 58 



Use of water by willows 64 



Use of water by wire rush 66 



Adjustment factors 67 



Soil characteristics 68 



Mechanical analyses 6 8 



Moisture equivalent 69 



Porosity, specific yield and specific retention 70 



Apparent specific gravity "2 



Chapter III 



INVESTIGATIONS IN MOJAVE RIVER AREA 74 



Procedure J6 



Consumptive use of water 81 



Chapter IV 



INVESTIGATIONS IN COLDWATER CANYON 88 



Equipment 93 



Controls 93 



Flume for winter measurements 94 



Flow recorders 96 



' Evaporimeter 97 



Evaporation and transpiration losses along the stream channel 99 



Loss from stream between controls 99 



Loss from stream above the highest control 114 



Comparison of use between controls with meteorological data 116 



Yield of water from drained slopes on Arrowhead Mountain 119 



(9) 



