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CHAPTER XXIX 



RELATION OF STREAM PLOW AND SUSPENDED SEDIMENT 



THEREIN, TO THE COVERING OF DRAINAGE BASINS. 

 By J. B. LIPPINCOTT, Civil iingineer. Resident Hydrographer U. S. Geological Survey 



Purpose of the work of the Hydrographic Branch of the U. S. Geo- 

 logical Survey. 



The Irrigation Survey, under the management of the XJ. S. Geo- 

 logical Survey, was authorized by the following Act of Congress, ap- 

 proved October 2, 1888: "For the purpose of investigating the extent 

 to which the arid region of the United States can be redeemed by 

 irrigation, and the segregation of irrigable land in such arid region, 

 and for the selection of sites for reservoirs, and other hydraulic work 

 necessary for the storage and utilization of water for irrigating, and 

 the prevention of floods and overflows, and to make the necessary 

 maps." This survey lasted until 1891, when a discontinuation of ap- 

 rpopriations by Congress brought it to an end. One of its principal 

 duties was the study of the water supply of the arid region. It was 

 considered as important to find the manner in which the streams 

 discharged as to determine the amount of the annual output. A stream 

 of constant flow, and with few floods, largely eliminates the necessity 

 for storage reservoirs thereon, the province of storage being primarily 

 to catch flood water and hold It ever for periods of drouth. Records 

 were begun on numerous typical western rivers, and were maintained 

 until 1891. 



Appreciating the value of this work, Mr. F. H. Newell was retained 

 by the Geological Survey to continue as many stream observations as 

 were possible, but in 1894 the Director decided that it was impossible 

 to set aside funds for this hydrographic work unless a special appro- 

 priation was made for that particular purpose by Congress. Mr. Newell 

 at once energetically undertook the task of getting this appropriation 

 to be expended under the direction of the Geological Survey. He was 

 successful in obtaining $20,000 to be available during the fiscal year of 

 1895-6. The work has been gradually developed in all portions of the 

 United States. It is evident that this work is closely allied to for- 

 estry. In addition to the question of lumber supply, the aim of for- 

 estry is to regulate the water supply. In an arid region this is the 

 principal province of the forest. 



