That's pretty cool, Zhel! It reminds me of the Innui who have dozens of words for "Snow".
I can't thinking of any distinction in those sorts of caves...though the act of exploring a cave is called "spelunking"
Similarly, I can't really think of the fine difference in the springs you mention, though your "vrelo" made me think of an "Artesian Well", but that is not generally a HUGE body of water-- can have a lot of volume, though.
Hmm.....we need Lev, I think
PS-- of course there are unscientific words like Brook, stream, creek, slough, etc....