If the emergency spillway goes, that's 30ish lake-feet of water that would drain uncontrolled. That would likely wipe out a few towns down the river.

I think gp was getting to the fact that the main spillway is eroding as well, and it could reach a point where it was unusable. In that case, with significant rainfall expected in the next week and a good deal of snow melt to follow, there could be huge amount of water coming into the basin with no way to control the outflow, which could result in much worse flooding.

Hopefully that all can still be avoided. It's a bit dramatic to say it's inevitable. It's a possible scenario, but it's also possible the right plan avoids it.

The emergency spillway was used because the main one was already badly damaged so they shut it off. Now they're saying the damage to the emergency spillway is even worse than the main spillway so their turning the main spillway on full tilt to drain below the level the emergency spillway activates.

The thing is... They drained below the emergency spill way level many hours ago and it's off, but they're still running the heavily damaged main spillway at full tilt. I think it's a last ditch attempt to drain the lake before the dam fails, they just don't want to say it because everyone will panic