How much water should a 7 yr old be drinking daily?

[bouncy]

Any idea's, I know the adult is 2 litres, but surely a child is different.

TIA

I don't know about water specifically but my DS1 is being seen by the Enurisis clinic and they advise 6 to 8 cups of fluid, advising against fizzy drinks, caffinated drinks etc.

Oh and DS1 is 7.