INCREASING REQUIREMENTS 223 



will become worse, but there are hopeful signs, too. There is 

 a trend toward dispersion of industrial plants and residential 

 areas because of the serious difficulties of traffic, transporta- 

 tion, housing, and plain lack of elbowroom in present indus- 

 trial and commercial centers. Security in wartime is a great 

 incentive to such decentralization. In addition, an increasing 

 number of water users are becoming cognizant of water in 

 their operations and are selecting sites where ample water 

 supplies will be available. 



If the nation's water resources are to meet increased re- 

 quirements without creating more and more problems than 

 already existing, intelligent development will be essential. 

 Many defects of the present pattern of development need cor- 

 rection, and there is need for more comprehensive planning 

 based on adequate hydrologic knowledge. 



The Ground-water Quota in Meeting These 

 Requirements 



It is estimated that wells and springs currently furnish about 

 one-sixth of the water for irrigation, industrial, and public 

 use: an average of 25 to 30 billion gallons a day. Ground water 

 is unimportant as a direct source for power, navigation, and 

 recreation, but is of considerable indirect importance because 

 the minimum flow of streams is sustained chiefly by ground- 

 water inflow. 



The selection of ground water as a supply, rather than 

 surface-water sources, has generally been on the basis of one or 

 more of the following advantages: 



1. Accessibility. Ground water may be reached within a few 

 hundred feet of the place where it is to be used, and on 

 the same property, whereas surface water may require 

 pipelines and rights of way over stretches of several miles. 



2. Availability. Ground water may be available for use in 

 areas where the water in streams and lakes has already 

 been appropriated by other users. 



