We have a narrow wooded area on our golf course between two fairways. Water naturally drains across one fairway, through the wooded area, and across the other fairway. Casual water occasionally occurs on the fairways. In the wooded area there are shallow ruts from drainage and exposed roots.
Is it required or optional to mark the wooded area as a hazard? Water is rarely present.
It's a tough decision because marking it would allow you to take a penalty and drop if you prefer. But it would also mean you couldn't move loose impediments if you wanted to play from the original spot. (there are usually lots of twigs, leaves, etc. in the area)
If we mark it, then we probably mark a LARGE area because there are several of the shallow (usually dry) ruts and we would just include them all as one hazard.