How to project basement level of humidity before building?
If you have to account for water penetrating the basement, then you likely don't want to be building a basement there.

If you're building from scratch, you'll ideally build a basement that is properly waterproofed and insulated from the outside and is set up to handle any drainage issues.

At that point, the humidity you have to deal with will be airborne. That humidity comes from the air...so for instance, if you live in MN in the summer, you'll note that it's incredibly humid. The basement tends to be cooler, allowing some of that humidity to condense, and basements tend to not have much air flow, so it can build up.

The solution to that problem is to include the basement as part of your conditioned space. Ideally it would have AC and Heat, but, barring that, you'll want to have a dehumidifier running.