crunch, that is exactly what Scott Cahill said. It had to be gates first. The erosion into the hillside was a problem but not threatening the dam....it wasn't cutting backwards to the lake.

If they use the spillway and the gates fail to shut, then water will run out until it reaches the bottom of the gates. If there is no erosion in the intake channel then everybody will relax and hope it stays that way for the melt season. Fix the gates next year.

But if Cahill's concerns about scour opening up channels under the gates happens, then the dam is doomed.

I read somewhere they were doing some grouting in the voids near the top to prevent that water piping scenario. Not sure if true. And I recently read that all of the piezometers measuring water flow underneath the surface have failed and none have been replaced. That seems insane. You need to be checking for water movement. Maybe they just aren't telling us, and they did install new ones?

The question is, how much time would there be if a channel opened up under the gates, to evacuate? A few hours? A day?