You get empty cans back when you drink them. I'm not sure if that is a bug then, but the strategy we used was to keep all the empty cans we got and turn them into cans of boiled water because we would get the cans back each time we consumed it. This allowed us to stay hydrated even if we got dysentery up to 66% from drinking multiple cans of water (10% dysentery from can of boiled water).
To get bottles of water you need to be able to craft the empty glass jars in bulk which requires a blacksmith forge and mold. Molds are fairly easy to make, getting the forge is the tricky part. Until then, the only reasonable way to get water consistently is with cans, which can be annoying because they don't stack, but at least you don't instantly die from thirst.