I agree that most of the writing has been rather poor. You are right that the main spillway (concrete lined) is lower than the emergency one. The main one has the gates that can be opened and throttled to control outlet flow. The emergency weir just does what it does when the water overflows the top. I’m amazed that the emergency spillway just flows over earth! That’s what the environmentalists were complaining about a decade ago — that too much dirt would be washed into the river if it were used.
Thanks for clearing that up.
So the only flow mechanism is on the main spillway. I read that they had to cut the flow on the main spillway back to about half on Sunday because they feared it would be undermined. That sent much more flow over the auxiliary one and severe erosion of the hillside.
So the rush is to get the main spillway close to full capacity, so the level will not rise up to the auxiliary outlet.
I’m sure they have the brightest and best working on this, but they need help from Mother Nature.
Hopefully, they can get enough water out of the lake before the next rains hit. They were hoping to lower it 50 feet, but don’t know if they can make that in time.