To add, I think that the issues that affect flow through the generation turbines also affects the relief valve system - there is a need to dredge and clear the river below. Lots of debris remains that was washed down through the damaged area below the main spillway.
Hi meyer, Have you seen this latest picture? They can't open any of the gates at the powerhouse as it is below the backed up river water level. They constructed temporary water containment walls with plastic (& sandbags?). Notice the rigged up piping.
It looks like they have removed the generator turbines/pumps as you can see the large empty area with the blue walkway. Normally there is a row of 6 of these huge units flush with each blue circular walkway zone. Crane rail booms above in the power house likely were used to pull these out (i.e protection measure of some very expensive generators & equipment).
