So while playing the other day, I had 31 Dwellers in one of my vaults. I only had 2 double-width Water Treatment Stations (not plants -- stations), each staffed with only 1 Dweller. 1 had 6 Perception, the other 9.
These 2 individuals were solely able to supply my entire vault which has: 2 double-width Power Stations; 1 single Power Plant; 2 double Cafeterias; 1 double Clinic; 1 double Medbay; 1 double Science Station; 1 double of each type of classroom; assorted and sundry living quarters and storage/depot rooms.
I KNOW "it's just a game" but it seems to me water production and supply should be MUCH more difficult than this as water would be integral to and consumed by most everything else in the vault; power and food production, med supplies production, consumed by the Dwellers themselves (I'm assuming there's some sort of advanced water-less waste disposal process in the vaults). I've gotten to the point that I keep otherwise-useless, armed Dwellers (YOU know who you are!) in the water production rooms just to help in case of rad roaches.
Anybody else think water is given short shrift?