Really? Where? Only place I've found water was a skin that was left for me near the start and only food I've come across is grubs from plants?
I assume if it's like ark you need to go into water with the waterskin equipped and then drink as and when you need to keep thirst quenched. Also not sure if it has a similar mechanic that the more physical activity you do (sprinting etc) the quicker your water levels drop.