What about bridging steel sheeting over the spillway erosion hole to stop the water from entering the hole. I’m thinking of that interlocking marine pier sheeting that is driven into the ground. At the angle of the hill and velocity of the water there should not be that much water weight that the steel would need to support. Not sure how large the hole is though.
Won’t work, its 300 foot long. You would have to literally build a bridge and then even plate steel wont hold up against the outflow.
They are about to abandon ship on this, they cannot use the emergency again, they are literally gouging out the mountain where the main spillway has collapsed which has piled up so much debris in the river it has flooded the main outlets at the power station. They cannot use them at all.
They desperately need to use the main outflow again. I hope they can shut down the spillway long enough to clear the debris in the river, or maybe use explosives.
And whats not being said is why the main spillway collapsed, two theories floating around is one, sabotage on the side gate which allowed water to get under the spillway, second is and underground hydraulic leak that lifted the spillway and buckled it.
A lot a drone video has been shot and subsequently erased from Youtube.
Last time they had eyes on the hole it was 300 feet long and 45 feet deep, it’s probably much worse now. Nothing short of a complete back fill and a months set time for a new slab of concrete.