PART II. 



GURLEY AUTOMATIC WATER STAGE REGISTERS 



III! IK CONSTRUCTION, INSTALLATION 



AND OPERATION 



INTRODUCTION 



FOR ili-- ini|M ..i ,,l,i., mm;,' < ..iihmioii* records of stream 

 llo\%. K i- necessary to eslal.h-h and to r.pnp permanent 

 stream gaging stations and to observe and tabulate 



.,-it.im data. 



each gaging station, a -t.tii..n < table 



the discharge corrr>| Hiding to all gage heights within the 

 .- preparrd. The n-Lh,,n-hip between gage 

 height and discharge remains constant as long as the control is 

 mi. hanged, so lh.it .1- l.-n- as the gage heights are accurat. K 

 re.id anil e.irefulK reeorded tin- data ohtam.-d will ! an urat.-. 

 lii.- discharge of uniformU tl>\Mn^ unregulated streams 

 at well selected gaging stations may be obtained by appl 

 to tin Cation di-rharp- table two daily gage heights per day, 

 ,-t \\hi. h oiu> is usually taken in the inoniing and tin- othrr in 

 th< ,\ ming. But such gage heights read morning and evening 

 \\ill not take art-mini <>l Middrn inrreases in stage due to floods, 

 ! to those due to regulation of the flow. To take account of 

 -u. h \ariation*. inrludinj; lho-e inrident to power regulation^ 

 of the stream, \\hirh materially affect the estimates of run-off 

 I -nm, tunes aiVeetin^ tin- iiionthlx HUMUS a> niiieh a> .'W) |MT 

 r.nt.i. it i- necessarN to in-tall uutomat 



It is aUo highly desirable, and in many cases, as a matter of 

 record, is essential, to u-- th.-m at an\ >tatin from which the 



reeords are l he u-ed a- a ha-i- of propoi t i,.nm- th- -tr.-ain 



flow among a number of users, as in power, irrigation, and 



mining prart 



