We sourced all our drinking water from streams, using concentrated iodine to make the water drinkable (I think we had to wait 30 mins for it to take effect).

There was one part of the journey where we ran out of water and couldn’t drink from a nearby small river because it was downstream of a paper processing factory. And we had to go out of our way using old school topographical maps (which we used for all our navigation) to find another water source and hope it was available and flowing.