12 CONSERVATION OF GROUND WATER 



be formulated. In the country as a whole, there are doubtless 

 some areas where soil conservation and water conservation are 

 mutually beneficial, some where either may be undertaken 

 without affecting the other resource, and some where conserva- 

 tion of one will be detrimental to the other. 



Few ground-water reservoirs are yet utilized to store flood 

 flows for later use, and they are generally not even considered 

 in river-basin flood-control and storage programs. Yet many 

 have a capacity far greater than the largest artificial reservoirs. 

 They can provide holdover storage with minimum loss of 

 water by evaporation and with minimum loss of productive 

 land. Some certainly deserve a far larger place in plans for com- 

 plete water development but cannot attain that place until hy- 

 drologic knowledge is sufficient to show the way to successful 

 manipulation of ground-water storage. 



The lack of adequate hydrologic data is recognized by tech- 

 nicians in all fields related to development and utilization of 

 water resources. Many have stressed the need for far more basic 

 data to ensure that these developments be sound and eco- 

 nomical. There is need for more research in the basic prin- 

 ciples of hydrology and in techniques and equipment for meas- 

 uring the quantities of water moving in each phase of the 

 hydrologic cycle. Comprehensive planning for development 

 of all water resources requires a well-coordinated analysis of 

 a great variety of data by scientists in many specialized fields. 

 The large number of Federal, state, and other agencies re- 

 sponsible for and authorized to conduct research in those sev- 

 eral specialized fields have endeavored to achieve this coordi- 

 nation on a voluntary basis but with limited success. 



The need for more ground-water data is especially acute in 

 river basins where comprehensive development of water re- 

 sources is planned or actually under way. In most river basins 

 the ground-water data are so meager that proper evaluation 

 cannot be made of the potentialities of ground-water reser- 

 voirs, and those reservoirs are therefore ignored in the develop- 

 ment plans. Indeed, the ground-water conditions are known 

 with reasonable reliability in only about 5 per cent of the Na- 



