xiv CONTENTS 



Watercourse Problems 136 

 Where the surface water is usable 138 

 Where the surface water is unsuitable for use 147 

 Where the surface water is used downstream 150 

 IV. Ground-water Problems Resulting from Land Oc- 

 cupancy 161 



Effects of Agricultural Use of Land 162 



Effects upon infiltration and overland flow 164 



Effects upon storage in ground-water reservoirs 170 

 Historic records, 170; Experimental research, 176. 

 Artificial replenishment of ground-water reservoirs 187 



Effects of Urban Use of Land 191 



Irrigation and Drainage 192 



Rising water table in irrigated areas 193 



Lowered water table in drained areas 194 



Regulation of position of water table 196 



Disposal of Wastes 200 



Sewage 200 



Chemical wastes 203 



River Control 205 



Reservoirs 205 



Regulated flow 206 



Levees and flood walls 207 



Navigation Channels 208 



V. Our Increasing Requirements for Water 213 



Consumptive Use and Waste 215 



Nonconsumptive Use and Disposal 217 



Anticipation of Future Requirements 220 



The Ground-water Quota in Meeting These Require- 

 ments 223 

 VI. Current Deficiencies and Future Needs for Effec- 

 tive Ground-water Development 228 



Hydrologic Data 228 



Adequate inventory of water passing through the 



hydrologic cycle 231 



Characteristics of ground-water reservoirs, 235; Inventory of 

 water utilization, 237. 



Manipulation of storage for maximum utilization of 



water 240 



Legal Concepts 243 



