226 CONSERVATION OF GROUND WATER 



than with stream flow, because we could not see what was hap- 

 pening underground. The natural flow in many ground-water 

 reservoirs has been sustained both in dry and wet years but 

 generally with more hindrance than help from man. 



In recent years there has been an increasing trend toward 

 regarding permeable rock materials as places where water can 

 be stored, rather than merely as places where water is stored 

 by nature (or was until man pumped it out). Many Califor- 

 nians are taking the lead in recognition of the opportunities 

 for putting water underground in storage for future use: the 

 water they propose to work with may be precipitation upon 

 the headwater areas, flood flows or winter flows of streams that 

 would otherwise continue unused to the ocean, and reclaimed 

 sewage and industrial water. The ground-water storage capac- 

 ity will be utilized wherever possible for regulating stream 

 flow and for holding water for sustained use. 6 



In several other states the complementary relations of too 

 much water on the surface during floods and not enough un- 

 deroTound when it is needed are receiving attention. As an 

 example, the Indiana Flood Control Commission is investi- 

 gating the potentialities of abandoned glacial valleys for ab- 

 sorbing floodwaters. The prime purpose of the Queen Creek 

 Reservoir now under construction by the Corps of Engineers 

 in central Arizona is to hold back floodwaters just long enough 

 to be absorbed by the ground-water reservoir of Salt River 

 Valley. Experiments have shown that fresh water can be stored 

 and later recovered from an aquifer that produces brackish 

 water under natural conditions. 7 



The ground-water reservoirs along watercourses are certain 

 to be drawn upon substantially to meet increasing require- 

 ments for water. The development of ground water there may 

 have the same effect upon stream flow as pumping direct from 



6 Berry, W. L., The California Water Plan, Jour. Am. Water Works Assoc, 

 vol. 42, no. 4, pp. 381-385, 1950. 



Conkling, Harold, Utilization of Ground-water Storage in Stream System De- 

 velopment, Trans. Am. Soc. Civil Eng., vol. Ill, pp. 275-354, 1946. 



7 Cederstrom, D. J., Artificial Recharge of a Brackish-water Well, The Com- 

 monwealth, vol. 14, pp. 31, 71-73, December 1947. 



