Like what
Shurutsue has said, Your natives needs Water to work, Gathering food by the natives are consider jobs
I prefer having Water Wells(or that Lab one having the widest range) over that rain catcher, make sure the Water well's circle covers everyone's
location point, they'll drink/eat by themselves
View attachment 4932129
There is also another factor, you being
far far away from them will cause them to stop working as the game de-load them to save you some RAM, making the game run smoother, I have notice when I'm at a location nowhere near them, the game doesn't really allow them to gather/dig/farm/chop/mine resources, it also affects on training too...
Spoiler due to showing the map.