There is no way any engineers would have planned this. They would never
have built a seating area surrounded by a flood plane.
The only way this could have happened would be if there was a bigshot
organizer with no common sense, telling the engineers what to do, like
Dilbert (comic strip) and he would have said "I don't care if it's risky, just
build it cheap. We're not putting in any fancy drains or bringing in any
truckloads of dirt. Just build it."
So, you get what you get. Been there done that.
Now, what are they going to do with it? Who would want this stupid
thing for anything in the first place? What are all those square prisms
for? It looks like Devil's Postpile, state park in CA.