THE UNDERGROUND WATERS OF SOUTH- 

 ERN CALIFORNIA.* 



BY 



WALTER C. MENDENHALL, 



U. S. GEOLOGICAL SUHVEY. 



IT often happens that in inaugurating 

 work along new lines only a few 

 far-sighted men are able to discern the 

 future bearing of that work, so that 

 those engaged in it are constantly met 

 with skepticism as to its usefulness. 

 This is particularly true in America, 

 where the direct practical question 

 What is it for ? must be met and a sat- 

 isfactory answer returned before sup- 

 port will be given to any line of activity. 

 This is no less true of governmental 

 than of private work. It is indeed much 

 more emphatically true of work of a 

 public nature, because as each citizen 

 contributes to the support of that work 

 he feels a personal interest in it, and, 

 true to the instinct of his race, demands 

 that it have a direct and useful bearing 

 upon every-day affairs. This is on the 

 whole a most healthful spirit. Its ef- 

 fect is to subject each public project to 

 a searching examination, in which those 

 who plan it must be able to justify it on 

 the broad basis of usefulness. 



Our government bureaus, which have 

 been created and have expanded in an 

 atmosphere of this kind, are eminently 

 practical. Their constant endeavor is 

 to secure results of direct benefit to the 

 body politic and of immediate applica- 

 tion in daily life. To the more abstruse 

 results, whose bearing upon practical 

 problems is less manifest or more slowly 

 realized, much less attention is devoted. 

 As a consequence there is little of the 

 aloofness in the public service here, 

 which marks it in some of the older 

 countries of the continent. 



The Geological Survey is one of a 

 number of such government bureaus 

 which endeavors always to guide its 

 work into useful channels and to give 

 it a direct practical bearing. When it 



came into existence, 25 years ago, the 

 value of such work as it was created to 

 do had been made manifest through the 

 geographic and geologic achievements 

 of its predecessors, the various trans- 

 continental surveys. Its maps, upon 

 which the physical features of the vari- 

 ous sections are faithfully shown, and 

 its reports upon the mineral deposits of 

 the West, and later of the East reports 

 in which the deductions of its special 

 students were made available for the use 

 of the practical mining man filled a 

 distinct want and led to the support of 

 the Bureau by Congress and to the 

 gradual extension of its functions. 



As the most attractive parts of the 

 West were settled and interest was 

 aroused in the possibility of reclaiming 

 its arid lands, the Survey, responding 

 to this interest, undertook a series of 

 observations to determine the amount 

 of water available for the purpose. 

 That branch of the organization which 

 undertook this work is known as the 

 Division of Hydrography. When, two 

 years ago, the plans for rescuing the arid 

 lands from their desert condition crys- 

 tallized in the famous Reclamation Act, 

 the Secretary of the Interior, to whom 

 was entrusted the task of carrying its- 

 provisions into effect, turned to the Bu- 

 reau, which for a decade had been col- 

 lecting the data, without which no sin- 

 gle project could safely be undertaken, 

 and the Director of the Geological Sur- 

 vey was instructed to take up the actual 

 work of constructing great irrigating 

 systems, to be sold at cost to the com- 

 munities benefited. 



Out of the experience of the Hydro- 

 graphic Branch and the Reclamation 

 Service there arose the need for a special 

 study of underground waters their oc- 



* Published by permission of the Director, U. S. Geological Survey. 



(44*) 



