Newborn babies drink ~750 ml of milk:
(45-90 milliliters) every 2-3 hours.
So the claim
The basic equation for determining this is by dividing your body weight in half.
is certainly not true without further restrictions on age.
There was a study regarding the 8 times 8 glasses rule (2002) which turned out:
I have found no scientific proof that we must “drink at least eight glasses of water a day,” nor proof, it must be admitted, that drinking less does absolutely no harm.
The reference list for water in Germany, Austria and Switzerland (2015) lists slightly different values by age, but not by weight:
They say the values can change with increased energy exchange, heat, dry air, eating salt, high protein input or illness like fever, vomiting or dirrahea. Weight is not mentioned.
If it were scientifically proved in 2013, I would expect the 2015 recommendations to consider these studies (or at least some update until 2020). The fact that Yuri Elkaim does not mention a study, makes me believe that it's just his own, limited observations.