Something I’ve noticed about human nature and even more in government situations, is the mindset that says, “If it ain’t broke don’t fix it”, which often means although some are vaguely aware that an underlying, latent problem may exist, it isn’t dealt with until its effect is manifested in some dangerous or catastrophic way.
Now that it’s “broke” we’ll see how they “fix it”. I’m very interested to see what they do to repair the main spillway. There likely will be reports given from analysis to what led up to the failure. That should be revealing (understatement).
One piece I’m curious about is what the top engineers thought the design “safety factor” was if the main spillway (and including the ES). Any good engineering source would know the extra margins of safety designed into all aspects of the project.
You don’t always know what you are going to run into. The Brooklyn Bridge construction is an excellent study. The designer & project leader was amazing. Even when they discovered that a vendor was cheating in providing poor quality steel wire, and a good deal of that wire had been already integrated into the suspension cables, they tested the strength of the poor quality wire and compensated the design with a greater amount of overall total high quality wire (to make the main cable “ropes”). This gave them the required “safety factor”.
There were other project challenges that very large project overcame. The bridge is still functioning to design today.