Well, where I live a whole lot of people need ordinary buses. Drainage seems a luxury.
That sounds snippy, but no kidding.
Drainage is not always a problem here and apparently no one is taught about it.
Both Diane's and my houses have the concrete graded toward the back door, mine in three ways. I saw it when I bought, but thought I had the money to fix it (I know grading). I gather whatever test there is for contractors here is very simple or rigged.