Survival water is your single most precious resource. The average person can only live 3 days at best without water and without clean and pure drinkable water.
Compare that to the fact that an average person can live 3 weeks without food. Not having a reliable source of survival drinking water is simply not an option for smart people.
If you are considering what to purchase for your survival stash, there is simply no single better choice that you can make than reliable, fresh, pure drinking water.