Watercarrier Backpack

A backpack/attatchment that carries water.

Core concept
A backpack that has fewer slots/an attatchment that goes on the side of the backpack. It carries water and liquids.

Personal twist
Am alternative could be a water purifier where you could get purer water from alchemy/equipment, thus removing the need to carry more water.

They have brought up that bags will have different uses so this sounds within the range of possibilities, plus I love the idea!