The sewers

[Unity]

I'm playing " Dracula: The Last Sanctuary ", and I'm in the sewers. I don't know if anyone's noticed, but it's pitch-black, and they expect you to find some kind of pool, which I'm supposed to drain. I've looked around for at least an hour, and I can't find the pool, or anything that might give me entrance to an unopen entrance/exit. Can anyone give me specific details on what to do in this area?
:confused: