KC Burke, earthresearcher,
what is that dark rectangle ? Some large piece of concrete slab?
I saw the pics and explanation, so its not a big slab of concrete....?
I guess what y’all are saying is that something could block the main spillway and thus all the water would go over the weir?
>>what is that dark rectangle ?<<
That is a good question. The two trees in post image 1,320 align with the trees in post image 1,346 - which aligns with the left image side edge of the “dark rectangle”. Why it is so dark is a good question. What is also of note is that the curved “J” part of the “approach wall” doesn’t really show itself in the turbulent profile in post image 1,320.
When/if things dry out and the inlet water levels are lower may clues be answered. (The coloration of the top of the wetted far concrete wall on the main spillway has a similar color). Just not enough information to answer well.