280 CONSERVATION OF GROUND WATER 



ally. The perfect syllogism of land and water management is 

 neither easy to define nor likely to be practiced, because the 

 forces involved, both human and material, are so complex that 

 they do not lend themselves to precise calculation and adjust- 

 ment. 



No two ground-water situations are exactly alike. Usually 

 they differ greatly with respect to the underground reservoirs 

 and the percolation of ground water. A ground-water reser- 

 voir is dynamic rather than static in character. Its water is in 

 flow even though at a slow rate, and the storage available may 

 have come from yesterday's precipitation or from that rain 

 which fell a hundred or more years ago. 



In each area the citizen is confronted, therefore, with a 

 different problem in which many rather than one circum- 

 stance control wise management. A grand generalization as 

 to what should be done in ground-water management is prob- 

 ably impossible to make. This does not mean that certain 

 important and universal guiding principles may not be ap- 

 plied. It is important for the reader to bear in mind, however, 

 that generalizations inevitably and invariably must be geared 

 to the local situation. A universal formula for ground-water 

 replenishment and withdrawal has no place in the thinking 

 either of the professional or the man in the street. The quan- 

 tity of water which may be safely withdrawn in one area may 

 not be safely withdrawn from another, and the physical meas- 

 ures designed to promote storage in one area would probably 

 turn out to be unsuitable and ineffective in another. 



The present volume has attempted to show, through exam- 

 ples, the experience of selected localities in this country where 

 ground-water problems have occurred. It has set forth the 

 factors affecting supply, development, use, management, and 

 protection. It has attempted further to indicate how each of 

 these factors may be modified or adjusted, within limits, to 

 produce the maximum values from this resource. One of the 

 constant characteristics of each of these locality discussions has 

 been the significance of local factors. However, before at- 

 tempting to illustrate by selected examples what is meant by 



