Here, a relatively low variation in {HEAD ~ water level} would indicate the presence of {TAIL ~ a siphonic phenomemon} 
Here , a relatively low variation in { HEAD ~ water level } would indicate the presence of { TAIL ~ a siphonic phenomemon }
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL