water intoxication involves drinking excessive amounts of water (read: gallons) in a very short period of time, so its unlikely you'd have to deal with water intoxication. you neglected to mention how much a "ton" of water is, though, but i'm sure that if you're smoking crystal it would be hard enough to over-hydrate yourself.
Remember that it's just a salt imbalance that kills you. Not the water itself. Buy a Lucozade or something else isotonic and drink a sip of that now and then. Water intoxication is excessively rare and the publicity of it on forums probably does more harm than good.
Two situations I'm aware of where water intoxication deaths have occurred. Schizophrenics and people with dementia can get in a water drinking frenzy with bad effects. Some military bootcamp deaths have also happened because in a desire to have no dehydration problems there has often been a requirement that people consume their whole canteen weather they were thirsty or not.
Generally a healthy person will find the concept of drinking more to be nauseating if they are so well hydrated that they are heading towards water intoxication. For most people an instruction to not drink if you are not thirsty is enough to prevent water intoxication.
I went to jail one time in a county where if you were in on a drug charge you had to piss clean to bond out. When I went in I was dirty for everything except alcohol and PCP. So I start drinking water until my piss looked like tapwater and tell them I'm ready for my UA. 12 hours later they come to get me. I had to keep drinking water the whole time because I don;t know when they're coming to get me. It fucked me up pretty bad, but I was drinking probably a gallon a day all fucking day. This shit is real, but you have to work at it.