All those pictures show houses that are mostly built above ground level and just have the earth banked over. And not too thickly eather.
That is a way of fixing the ground water issues.
Most of the good info I've found, for underground habitable construction, is from companies/sites dealing with cellar building or converting.
Yeah. The ones I posted aren't true bunkers. They're either built into a hillside or have earth banked up the sides. They are very practical for their purposes though (the ones I mentioned regarding storm resistance and temperature stability) And yes, our big problem with true underground construction here is ground water just as you mentioned.