YOLO! Be brave with the water effect, friend. I've personally found that every time I do something that scares me because of its potential to ruin a ton of hard work, it always works and comes out very, very good.
What did you use for the tree stumps? I can tell you added the brush to it, but what is the wood? Store bought or real?
This is going to be an epic experiment. Your base work recently has been off the hook! I always walk away inspired....about to PM you.