WATER LOSSES FRO.Ar WET AREAS 



95 



PLATE XXII 



COMBINATION FLUME FOR MEASUREMENT OF WATER AT BOTH HIGH 



AND LOW STAGES. 



across the entire width of the flume. The large flumes should, therefore, 

 be rated iu place when the conditions are extreme, such as are indicated 

 in the example cited. 



With clear water it is best to set the gaging station so that there 

 is the least possible grade in the approach channel to the flume. "Where 

 heavy loads of detritus are being transi)orted, deposition will occur in 

 tlie entrance to the flume where the grade is flattened at the installa- 

 tion, and enough debris may lodge to affect the measurement. Usually, 

 however, other conditions, sucli as bedrock exposure in the channel, 

 will determine the location of the station, and it will be found more 

 economical to rate the large flume for the given set of conditions after 

 other factors have determined its location. 



