Earthen emergency spillways are designed to erode gradually and release dangerous volumes of water in a controlled manner to prevent down stream catastrophe. Oh, by the way, the emergency spillway is designed to be destroyed in the process, draining the body of water behind it.
“Earthen emergency spillways are designed to erode gradually and release dangerous volumes of water in a controlled manner to prevent down stream catastrophe. Oh, by the way, the emergency spillway is designed to be destroyed in the process, draining the body of water behind it.”
I’ve designed a few dams. You never, ever, never, never, never want the dam to be overtopped in any way, or to erode in any fashion.
And the spillway is meant to be armored (grass, rip-rap, concrete..whatever the velocity merits) so it does not get destroyed.
I have no idea how erosion from an overtopped dam can be considered gradual or controlled.
I guarantee that this Oroville dam is experiencing an event beyond its design parameters, and it is not at all eroding slowly or gradually...and frankly nobody knows what might happen. I pray it holds long enough to draw down - but its gonna rain again soon :(