DEPARTMENT OF THE INTERIOR. 



UNITED STATES GEOLOGICAL SURVEY. 



P. H. Newell, Hydrographer. 



RESERVOIR SURVEYS. 



At the present time the subject of water storage is being widely 

 discussed and many questions are asked by correspondents regarding 

 the surveys and examinations of reservoir sites made by the Geolog- 

 ical Survey. This circular has been prepared as a reply to such 

 letters. 



LEGISLATION. 



The organic law from which has grown the present work of the 

 Geological Survey is dated March 3. 1879. It creates the office of the 

 Director of the Geological Survey, and states that "this officer shall 

 have direction of the Geological Survey and the classification of the 

 public lands and examination of the geological structure, mineral re- 

 sources and products of the national domain. '' A fundamental function 

 of the Survey is, therefore, the classification of the public lands, a 

 work which cannot be accomplished until a thorough knowledge is 

 had of the water resources, since for the most part the public lands 

 are within the arid region. The Geological Survey has not only to do 

 with the fundamental scientific problems relating to the earth but 

 more largely with present and prospective developments of mineral 

 resources and products. Throughout much of the United States the 

 principal mineral of economic value is water, and the study of the 

 distribution and fluctuations of the water supply is among the most 

 important of the functions of the Survey. 



The work of the Survey is not confined to the public lands, for 

 later acts of Congress have extended its operations to the "national 

 domain", which includes all of the territory within the possession of 

 the United States. In every State and territory surveys have been 

 or are being made. The extent of these is governed by many con- 

 siderations, such as the economic and scientific importance of results 

 and the aid or cooperation of individual States. 



From the initiation of this Survey in 1879, much attention has 

 been given to the arid region, its great possibilities having been early 

 appreciated. In 1887 the Director was called upon by Congress to 

 consider the question of Federal recognition of the irrigation subject, 

 and in March, 1888, a resolution was passed requiring the Secret ary 

 of the Interior, by means of the Director of the Geological Survey, 

 "to make an examination of that portion of the arid region of the 



