Can the same area value be found in multiple departments? If not, I don't see the need for an area/department junction table.
Not sure what the reason for junction for owner and employee since owner was described as the one who owns documents. It may be valid but without really understanding the relationship, not sure of that one either. The only other comment would be your use of what looks like multi-value fields (since I don't use them and probably never will, I can't say what they look like in a relationship). Many of us here would not use them. AFAIK, their primary reason for existing is to work with SharePoint lists. Beyond that, you may find that some of your queries won't work.
The more we hear silence, the more we begin to think about our value in this universe.
Paraphrase of Professor Brian Cox.