How much water to drink while BF?

Nad
I have a very low supply and I feel like I've done everything to increase it. I pump 1 1/2 oz at most before she feeds. I know water intake is important during BF but how much is more than normal? I drink at least 64 oz a day, sometimes double that and no change. I'm 5'3 150 lbs. can you BFeeding moms tell me how much I should be drinking, how much you drink, etc. I'm at my wits end with this. I'm desperate to increase my milk. Any tips (don't have to be water intake related) are welcome! 
PS: my baby is 7 weeks old. I've been in a pumping schedule Recommended by my lactation consultant ever since.