You should bring a gallon or two of water for you to drink on your way in, in case you have trouble finding the camp. The camp will be providing a lot of water which we will use to cook and clean with in the kitchen. We'll also have water as well which we'll offer for showers, as long as our camp supplies hold out. The water team will monitor the water use and ensure that we have enough to do cooking and cleaning for the rest of the week, and send a crew out to Gerlach or Empire to get more water when it is needed.
You may also want to bring other drinking fluids such as gatorade, or other flavored drinks which are non-alcoholic and uncaffineated.
More details are here: http://www.burningman.com/preparation/event_survival/water.html