Water from atmospheric moisture
 

I think that given the situation in most post-apocalyptic games, sooner or later, somebody is going to create something like this - a small tower that collects moisture and lets it pool into a suitable container.

https://www.greenprophet.com/wp-cont...ater-tower.jpg

Even though this might appear to be a new idea, the principle has been used in the past to collect water, everything from tying rags around your legs to soak up water as you walk through sodden grass to hanging out sheets during misty weather or at night to collect morning dew.
What makes this different is that it was created to supply water for more than just one or two people, these towers can apparently collect up to 100 litres a day (but I'm willing to bet that depends on atmospheric conditions).

Plus it uses low cost and lightweight materials and it was specifically designed to allow construction by unskilled workers without access to electricity.
I think variations of the idea could occur depending on the need, available materials and weather conditions as long as somebody gets creative enough to imagine it.

YouTube video: -
https://www.youtube.com/watch?v=THJVuinPbc0

Website with more specific information: -
https://www.warkawater.org/
https://www.warkawater.org/warkatower/

Other websites: -
https://www.greenprophet.com/2014/12...t-of-thin-air/