There are many theories about water. I personally think anything more than a gallon per day is hideous, that's my opinion. Keep drinking and if your using a trainer, she what that person says about what to do the week of the show. For me, it was something like:
Sunday - 1 gallon
Tuesday - 1 gallon
Wednesday - 1 gallon
Thursday - 1/2 gallon
Friday(morning) - 1/4 gallon
Saturday(show) - just sip if needed
Again, that is what I have done in the past and have put a couple clients through and they came in dry.
Good Luck,