re: Pylons in the water 1-10w on spillway

The ones that ran parallel to the I-10 were a sea wall. We used to ride our bikes on I-10 before it was opened, I think it was around 1972. The perpendicular wall was still intact, even had some trees growing on it. The parallel wall was just pilings by then. My dad said it was a sea wall long ago (told me this in the 70's) and people used to go out there and hang out.
He also said there was a civil war cannon out there past the bend in I-10 that was underwater.