What should be the daily water intake for 12 year old?

Although it is not permitted, you are able to. Although many would agree it'd would be probably not the best idea.

I could understand if you drank that much if you were outside, jogging, but if it's just for a silly reason, then it could be a health risk. Water, although good for you, can turn slightly bad for you, when you drink to much. If I were you, I'd probably look up a resonible ammount of water to drink.

So like I said previously, I could understand for a good reason for example if you were dehydrated, but for silly reasons, I wouldn't believe it would be good for you to drink so much water.