Okay, not really, but that's the visual association I got from the scene. You see metal plaques around street drains here that say "Caution. Sewer drains to river," with a picture of a fish. This looked to me like some giant, rough pipe that thrust out of the levee next to the Mississippi.
But of course it isn't. It's in Citygarden, one side of the large sculpture Eros Bendato that's been seen here before (e.g., https://saintlouismodailyphoto.blogspot.com/2013/08/all-you-need-is-love.html). You can crawl right in there, and lots of children do. I just don't want to see that worker washed away by slime.