I dunno if if this is a bug or not, but I thought I'd throw this out there. In the sewers when you go into chute #1 (counted from left to right as you come into the room with the four switches) and go into the control room and press the switch that looks over the large room you need to cross, the room always
fills up--no matter what the state of the other switches are in the other control rooms in the other chutes.
The other thing is even if you've flipped all the switches in the other rooms and then flip the one in chute #1 and see it fill the room, once you exit that area and go into chute #2 to the large room it's no longer flooded.
Maybe I'm missing something, but this seems like a scripting error to me.
Also, the switches in the other rooms (other than the one in chute #1) don't let you turn them off once you activate them. Doesn't seem like much of a puzzle to me--but I could
be missing something obvious.