You need water, all the time, every day, & lots of it!
You don’t need anything special but sometimes there are advantages.
Camelbacks are great by themselves for cycling or short hikes near safety.
The “Zombie Apocalypse” calls for something much more robust than a pop bottle or a camelback. A full on battle rig, dual canteens, metal canteen cups (Not shown here), Fanny pack (For the pop bottle) as well as the Camelback!