Maybe in areas with common rain the player can get some degree of renewable rainwater, albeit incredibly slowly. There would probably need to be a substantial upfront cost and such rain collection process likely wouldn't be very efficient unless the player invests a lot of time and effort into it.
I'd love to see fog and storms integrated into the game in some way, even if its only for a set area/scripted event.
Edit:
Perhaps there could be a cold & snowy area where you might become really cold when a unit of time passes, especially at night, if only there was somebody soft and warm there you could snuggle with ;3c
