[dukha]

I don't agree it's a logical move.

a) tap water is going through decontamination procedures

b) there is no evidence that tap water can transmit virus

c) if you don't trust tap water you can boil it easily

d) even in single household people are not really drinking from shared pool of water

It can be argued that it's better to have water and not need it rather not having it in the need, but on the other hand if you're at the point where basic needs like water and electricity are not provided anymore lack of stockpiled water is unlikely your biggest problem.