Drinking enough liquid is important, but recent studies have found that you can easily throw your electrolytes out of balance by drinking too much water. For this reason, the ACSM no longer recommends even 8 glasses a day. Instead, you're supposed to drink when you're thirsty and if needing excessive amounts of water, make sure to consume some form of electrolytes as well.
Because of the way creatine works, you could probably get away with more water, but I'd recommend experimenting with throwing in an electrolyte supplement some days and not throwing it in other days, and seeing which days you have the better workouts on. Try it out.