Originally Posted by FreeMe
Originally Posted by Steve
Main spillway. Couple of days ago v. today.

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It's abundantly clear that the failure began at a seam in the concrete, where I would bet anything that the seal had been lost and water intrusion has been allowing the rebar to rust.

Years ago, I was involved in a whistleblower event regarding a bridge that was on the verge of collapsing. My voiced concern was blown off by the controlling authority initially, with explanation that fractures in concrete were not a problem unless rebar was rusting - and rusting rebar would have to be evidenced by rust stains streaking the concrete. My follow-up photos showing the rust streaks, along with threat to go public when the bridge fails, drew immediate and dramatic positive response.

Originally Posted by Middlefork_Miner


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I'd bet that the photo posted above from 2013 shows when crews were out there looking at rust stains. Makes me wonder what else might not have been reported or dealt with.


Looks like it may have failed from undermining. Percolation from the earthen dam created voids under the slabs.