Is giving water to Babies after taking breastmilk harmful?

Breastfeed babies do not need water to supplement their feeds as compared to formula fed babies as breastmilk is 80% water. Also, it is not advisable to give water to 6 months and below as their livers are not fully developed yet and puts them at risk of diarrhoea and malnutrition. http://www.who.int/features/qa/breastfeeding/en/