I agree for the most part, but that strategy would have been fine without spillway damage... shutting the spillway in the middle of the heaviest sustained rain of the season got them on the wrong side of the curve... if they could have run 100k CFS throughout the last big storm (which would have been pretty standard given the inflow rates), they’d have been fine. If anything, this is a call to review procedures at all dams to better prepare for failures at the worst possible time... analyze the reliability of redundancies and verify their performance if necessary and prudent. The procedures in place are assuming proper maintenance and operating condition... lacking that, the status quo has significant risk.
I think that post-event, if the entire structure survives, they need to develop another way to move water quickly and safely. Well, obviously, they need to fix the main spillway. But they also need to re-think the emergency spillway and perhaps add a gate to it so that they can spill at a modest amount long before water pours over the top.