326 



CONSERVATION OF GROUND WATER 



Quality of water, legal rights to, 255 

 from soluble rocks, 76, 148 

 (See also Contamination; Treat- 

 ment) 



R 



"Rain making," 251 

 Reasonable use of water, 245 

 Recession of glaciers, 173 

 Recharge, artificial (see Artificial re- 

 charge) 



by irrigation water, 193 



by precipitation, 189, 192, 242 



by streams, 188, 206, 208 



limited, by climate, 40-43 

 by geology, 42—47 



rejected, 127, 206 

 Recharge areas, definition of, 29 



proportion of total land area, 190 

 Recharge basins, 143, 188 

 Recharge ponds, 53, 128 

 Recharge wells, 73, 100, 125, 147 

 Recirculation of water, 80, 141, 273 

 Recreational use of water, 215 

 Redistribution of wells, 100, 120 

 Reduction, in pumping, 60 



in waste of water, 61 

 Regulation of development and use, 



61 

 Reuse of water, 215 



legal rights in, 255 

 Rice irrigation, requirements, 49, 106 

 River-basin development, 229 

 River infiltration, 138 



reduced, by industrial waste, 204 

 by silt, 144, 207 

 Runoff (see Overland flow; Stream 

 flow) 



S 



Safe yield, 261 



Saline water, suitability of, 126, 130, 



150, 238 

 Salt, left by evaporation, 59, 199 

 removed from soil, 221 



Salt-water encroachment, from con- 

 taminated streams, 149 

 from navigation channels, 208, 210, 



212 

 from oceans, 51, 123 

 from other aquifers, 57, 109, 134 

 from tidal streams, 148 

 through drainage structures, 195 

 through wells, 44, 53, 131 

 Salvage of unused water, by creating 

 storage space, 55 

 by diverting to areas of shortage, 



70-76 

 by reducing natural discharge, 80- 



82, 94, 95 

 water rights acquired by, 252 

 Sand aquifers, 47, 128, 135 

 Sandstone aquifers, 101, 119 



poorly permeable, 115 

 "Saved" water, 221, 252 

 Sea level, rise in historic time, 174 

 Sediment, in reservoirs, 181 



in streams, 187, 208 

 Sewage, natural purification of, 201 

 Sewage effluent, 54, 67, 126 

 Soil moisture, 28 



increased by conservation practices, 



163-168 

 legal right to, 251 

 Solar energy, 15 

 Spreading areas, 67, 189 

 Spring discharge increased by irriga- 

 tion, 90 

 Sprinkler irrigation, 221 

 Steel mills, water use by, 80 

 Storage space, as an asset, 226 

 created by pumping, 50, 71, 113 

 inadequate for current use, 140 

 Stream flow, inventory of, 21 



relation to ground water, 138, 150— 

 160, 266 

 Subirrigation, 88, 194 

 Subsurface storm flow, 177 

 Supplemental irrigation in humid 



areas, 220 

 Synthetic oil manufacture, require- 

 ment for water, 222 



