PE Teacher Question / Concern

3rd grade gym class.. The class visits the water fountain 
on the way out of class.. If the class has been noisy or
presenting any discipline issue, they are denied water after 
 P/E .

I jogged thru my school life, and I realize that the 3rd 
 aren't doing anything incredibly strenuous, but It strikes
 me as a little bit unwise to not hydrate , and certainly
 not a bright idea to use water as a method of discipline.

Noisy kids should get some justice, but does this sound right? 

Any opinions on the subject?