find a hill blast it to fill dirt status and repair the dam.
No can do. Any hill they might choose will have to be analyzed for endangered species for fifteen or twenty years, after which it will be found to be the one and only habitat of some unique species of puffing titgrouse, and therefore absolutely untouchable.
Easier to bring the dirt by barge across the Pacific Ocean from Indonesia, or perhaps by jetliner. Two or three hundred thousand trips ought to do it.
There’s a lot of slurry mix (if not straight concrete) under the actual spillway structure slab. The should actually have a mobile plant out there making concrete. Whoever is testing that concrete is going to have a LOT of cylinders to break!