The trees are in the river because the water is an object layer like the road and not actual water. I suspect it will stop GV's and planes while allowing PT and LVT to navigate on it. Wonder if that means we now have high elevation water objects that can be used as high alt lakes?
---Update---
Oh shnizzle, I just realized I will have to test the boundary at the river shore berm to see how close I can paint trees and not have them popup in the river. In Africa during the dry season, the banks of rivers have greenery and trees because of the water. I'm doing a rift valley type theme on my new terrain with lots of rivers for bridges. Next question will be do the end berms of the bridges have to be set outside of the river bank berms or will it cause object on object z-fighting? More testing......