Help with very basic construction, generalized building code info?

We have a situation with the neighbor. Without getting into the history of events, other than to say we have gone out of our way to accommodate her, here is where we are now: This really is the short version.

Our neighbor is planning to install a berm (?) in her backyard along our driveway – 2 feet underground and 6 inches above. This will turn our driveway into a swimming pool during heavy rain and possibly cause flood damage to our home. There may be things we could do to counteract the impact to our property, but they would be things that would piss her off and I really don’t want to participate in Driveway Wars. She has the money for this crap. We don’t.

We will need to call the county at some point, but I am trying to wait since we received this information through mutual neighbors and I don’t want to put them in the middle of things. Still, I want to get an idea of where we stand. I have read the county building code online, but can’t understand it well enough to get much out of it. I don’t know if this thing is a berm, a retaining wall, a permanent structure or what and I don’t know WTH “unbalanced fill” means.

I know that these things differ by area and I will eventually need someone to officially assess the situation in person, but does anyone have some general, basic information about the questions below? Even an educated guess would be appreciated.

1 – Is this berm/wall of hers a “structure”?
2 – What is a typical set-back (distance from property line) for this sort of thing? (Our property extends slightly past our driveway.)
3 – What does “unbalanced fill” mean?