CURRENT METERS 63 



SELECTION AND LOCATION OF GAGING STATIONS 



RECONNOISSANCE 



-l.i.Mii the best results with a -urn-nt meter, stations 

 .should he located only at sites well adapted to its use. The 

 same cart* ful aitt iinmi -li..uld ! n\.-u t<> the selection of a 

 m i. -lit iii.i.-i >t.iii.ii as is given in establishing a system of 



;ol |,,,mt. t..i .1 tojxigraphic survey, in which case the 

 mi'ir proldem is roii-id.-n-d liom .ill \i.-\\ point*, only sueh 



rol points being located as will give consistent and 

 rate results. 



The final location >( the gaging station and the choice of 

 equipment to !* in-l.ill. .1 \\ill -I- |- ml \rr\ l.iiu'--l\ on a thorough 

 reconnoissance. This work is of equal, if not gn-.ii.-r. impor- 

 tance than any other detail connected with the location of a 

 gaging station. It -li.-uld IK? performed by an engineer exper- 

 ienced in stream gaging work. Poor results obtained at many 

 stations may be traced directly to the fact that such stations 

 are not properly located. 



When selecting and equipping a station, while considering 

 the present use of the data to be obtained there, the importance 

 of all possible uses for which the records may be required in 

 the future, under changed conditions, should be kept well in 

 mind, and all the return -MM -nt- should be coordinated as com- 

 pletely as circumstances permit. 



If the greatest immediate value of the data is for a power 

 >iud\ in .1 -i\. n drainage area, locate at or near the center of 

 the power zone a primary or bast* -Lit ion, and elsewhere as 

 in. my secondary -t.it io MS as may be necessary. For this par- 

 titular case, as in any other water supply problem, the base 

 station should be placed at tin- >trateuie point on the main 

 stream. and all data collected in the basin should be compared 

 with the data obtained at the base station. 



\- ili- object of the reconnoissance is to find the best loca- 

 tion that will furnish the desired data, it is well before locating 

 the primarx -t.ition to examine the locality carefully du 

 various stages of flow, considering the stream under ice con- 

 ditions, as well as during the summer season. At low stages 

 the bed and the minimum veloeit\ . .m be examined, and some 



