I was looking for an answer on forums and on wiki guides, but couldn't find specific one, so I'll ask here:

I'm not doing quest The Black star, I discovered Ilinalta's deep by luck and cleared it through. Then I read on the wiki that a pulling chain removes a boulder to 2nd zone - Ilinalta's deluge. However, I didn't read anywhere that this area is available only after you acquire the appropriate quest. The boulder doesn't open for me, so I'm asking - does it remove only when on this specifc quest or should it remove itself in any case?

Thanks!!

Given that a lot of quest-related locations have areas that are only accessible if you are on a particular quest, I would say that it's probably the same thing here.

According to UESP:

The way that's worded makes it sound like the second part of the dungeon is only supposed to be accessible if you are on the Black Star quest. Otherwise pulling the chain lowers a bridge but does not open a passage to the Deluge section.

I see.

Thank you, at least I won't bother with it anymore.