ARGGHHH stuck on this sewer level! (please help)

[Mystical_Ice]

I'm in the 'sewers', running around... and i dropped down into this room, onto some barrels, and there's a bunch of those red things flying around and attacking me. i killed them all, but now i'm STUCK... and i've been looking around for half an hour, and i can't figure out where to go. there's the "big" room with the flammable barrels (first picture), then if i climb down the ladder, there's two pipes (i can't get into) with water. then if i climb UP the ladder onto the pipe, and walk down it, i come to another room, with water in the bottom (third picture) and ladders and stuff... no way out as far as i can see.

what am i missing? someone who's played this want to help me out? thx

EDIT: lowered picture quality so they weren't a few hundred KB

 

[HWHorathla]

turn the valve in the 3rd screeny so the water level rises, then go back into the room where all the explosive barrels and manhacks were and go down the ladder into the lower level thro a little tube and up

 

[Smoove]

Go to the opposite room.

Spoiler

Climb down and open the valve to flood the room, you will then swim down and break open boxes to release a wooden cable reel - that will allow you to climb out and move on.