Source please for your water "fact."
Both of my parents are doctors. They have 50-60 years of experience between them in the medical profession, and they regularly have to deal with de- and overhydration. I talk to them about medical stuff. They told me.
Mayo's website describes 3 litres per day for males as adequate. That's not even a max.
There's actually not a consensus on how much water you have to drink, per day. Some people say six, some eight, some ten, glasses. If you sweat a lot, due to physical exertion or even just biological propensity, you can safely drink more. How much more...

Obviously, the limit varies from person to person and region to region.
Mayo's the only source I've
ever seen cite 3 litres as "adequate".