I parked near the outfall, and walked around for a while. I went downstream from the outfall just to see if there were more outfalls into the creek, and sure enough, there was a just-walkable RCP outfall not far downstream. As I approached it, I heard footsteps inside! It was a couple of taggers.

This drain is nice, but fairly featureless. It's big and long, and has nice, older concrete work. There is one walkable tributary, a 72" semi-elliptical pipe; I didn't go far because I didn't have much time, but at some point it starts to smell a bit like there is a sanitary sewer leak into it, or maybe an illegal connection.

The one junction

Given the taggers I had just seen, I was also surprised to find very little graffiti in this tunnel.

Came out the infall, walked back above ground. Very fun little trip! I found out my waders had a leak!