Anybody here who has experienced not giving water to formula-fed babies? I've read somewhere that babies do not need water. How true?

I have not given water to my baby because he's still in my tummy, but as a member of the Breastfeeding Pinays group, I've read that too much or excessive water may cause water intoxication among babies. Some scholars say that even a few mL of water may affect blood sodium in a baby's body. This isn't good because it leads to electrolyte imbalance. Even a slight change in a baby's electrolytes is detrimental for his/her health as it may cause tissue swelling.