Okay, capitolising on that whole 'mob mentality' you slide, one after the other down the drek-slide, and into a 'pool' as it were... you can't touch the ground, ... but even if you were tempted to dive down and find out how deep it is, you really don't want to. Then again, you may not have a choice...
<Inventory check> Who's encumbered? if you have more than your body rating in Kelo's of gear, you are sinking...
Okay, that being said, there are two waterfalls leading out, one to sky, one back the way you came. there are lights bouncing arround like someone running is carrying them down the tunnel you just exited, there are ladders allongside each of the 'waterfalls', and one deeper dump basin going further underground. the dump basin is covered by a trash grate at the bottom (much like the one that was rotted out where you were last) but it is open to the sky. (so, you can't swim under it, but you can jump over it / climb over it)
there's an onimous sucking sound coming from that dirrection.