I can’t help but wonder about the sheer vastness of scale of this project dealing with such incredible masses of water and dynamic force.
At the time, was there anything comparable to this project meant to artificially contain such force and scale of dynamic-water force?
One wonders if part of the problem may have been possible miscalculation of the incredible, tremendous force of water at full load on this enormous spillway.
It worked for fifty years without a problem, so the system was relatively sound. Something changed in the last few years. If the system deteriorated, that means maintenance was neglected.
B-52’s are still flying 60 years on. I can’t believe a concrete structure, properly maintained, won’t last at least as long.
Bid dams had been built for many decades prior. Sure, it was tall. The spillway length and slop was and is very massive but many dams like Hoover Dam had been built in the 30s and after prior to this structure.
The 1880s Johnstown dam failure was a spillway event but I don’t know how similar the spillway was so knowledge of this being a critical feature was not new ground.
I still think that a junior engineer was detailed to show a french drain under the slab and as he started to detail it out in a normal manner someone stopped him and said, the bulk of the spillway slab is going to be on rock and we don’t want to have them cut individual channels in the solid rock. He drew something else and no supervising threw it out.