78 W. & L. E. GURLEY, TROY, NEW YORK 



CONDITIONS REQUIRING THE USE OF AUTOMATIC 

 WATER STAGE REGISTERS 



The conditions requiring the use of automatic registers have 

 been admirably discussed in detail by the Engineers of the 

 United States Geological Survey.** 



It may be said that automatic water stage registers are 

 necessary: 



1. WHERE WATER is VALUABLE AND EXCEPTIONALLY 



ACCURATE RECORDS ARE NECESSARY. 



In irrigation enterprises information concerning the quan- 

 tity of water that can be supplied is necessary to interest capital, 

 and the accuracy of the stream-flow records will determine not 

 only the feasibility of a project, but in a large measure the 

 future of the community interested. Recent development in 

 the West has created a demand for water, and the quantity 

 available must be accurately measured before the water subject 

 to filing or the quantity in excess of prior rights is known. 

 Owing to lack of stream-flow data, many streams are over 

 appropriated by water users. Often the discharge of the 

 streams on which such conditions exist is small and difficult 

 to measure. In determining the flow of a stream subject to 

 additional appropriation of water, the automatic register is 

 absolutely necessary. 



2. WHERE THE ARTIFICIAL OR NATURAL CONDITIONS ON A 

 STREAM CAUSE SUDDEN CHANCES IN STAGE DURING THE 24-HOUR 



PERIOD. 



Sudden changes in stage due to natural conditions may 

 occur, on streams draining areas of high altitude and fluctuating 

 with melting and freezing snows. A stream subject to change 

 because of the climatic conditions may show great variation 

 in stage within the 24-hour period, especially during the spring 

 or when the mountain snows are melting, the effect depending 

 to a certain extent on the distance between the gaging station 

 and the mountainous section of the drainage area. At a station 



By Mr. Glenn A. Gray. M. Am. 800. C. E.. DlRtrlct Engineer. In a 



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ir. Q II. Pierce, M. &fl - ' i:.. Ui-.tri.-i KIILMIM <T. in < out ril.u- 

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