TABLE OF CONTENTS 



Page 



LETTER OF TRANSMITTAL x 



ACKNOVLEDGriENT xi 



ORGANIZATION, STATE DEPARTMENT OF PUBLIC WORKS xii 



ORGANIZATION, UNITED STATES DEPARTMENT 07 AGRICULTURE xiii 



INTRODUCTION 



CHAPTER 1 



CHAPTER 2 



RELATION OF PLANT COMMUNITIES TO MOISTURE SUPPLY 5 



Drought-resistant plants 7 



Indicator value of ground-water plants 10 



Marsh vegetation 14 



CHAPTER 3 



METHODS OF DETERMINING CONSUMPTIVE USE l6 



Tank measurements l8 



The Mariotte tank 19 



Float valves 22 



Factors affecting the use of water by vegetation grown 



in tanks 23 



Soil-moisture studies 28 



Stream-flow studies 30 



Water-table fluctuations 3^ 



CHAPTER 4 



im^STIGATIONS OP THE DIVISION OF IRRIGATION 59 



Basis and scope of studies 39 



Santa Ana Valley, California 39 



Saltgrass 41 



Wire rush 43 



Willow 43 



Bermuda grass 46 



Tules and cattails 48 



Brush ^5 



Grass and weeds 59 



Mojave Valley, California 39 



Tules 39 



Adjustment factors for large areas 62 



Temescal Creek, California 66 



Canyon-bottom vegetation 66 



Supporting tank data 70 



Probable limits to the losses along stream channels 71 



Coldwater Canyon, California 74 



Canyon-bottom vegetation 74 



Stream losses by evaporation and transpiration 79 



Studies in the Sacramento-San Joaquin Delta, California 85 



Tules and cattails 83 



ueeds 85 



Northern Colorado studies 88 



iii 



