I'll be posting some more pictures here from the drains/sewers in my city. But for now, here are some photos of one CSO section (the segment between the diversions and the river) that we explored about a month ago:
The brick wye not far from the entry
Our entry point
Looking up a branch (note the nice brick floor)
Detail of where the stone invert meets brick side. Most of the sewer downstream of the diversions is like this.
Sewage flowing into a diversion pipe
Less sewage flowing into another diversion, from above
Me, standing in shit, pointing back the way we came
The huge weir in the diversion structure that diverts most flows into the new CSO tunnel
The super-scary ramp that leads down to a ~100ft vortex drop shaft, into the CSO tunnel
And finally, in the largest section of the sewer (9 ft diameter) -- a photo taken by a friend (but that's me doing the lighting and modeling)
Add to all this that we found by the entry what I believe is a tag by the old PVC group ... and you have a completely awesome sewer (for Portland, at least).