“... DWR spokesperson Lauren Bisnett said the department estimated there
was 500,000 to 1 million cubic yards of debris in the Diversion Pool.
The higher figure is the equivalent of a football field
stacked 470 feet high with debris, she said.
Figuring that mass in terms of dump truck loads that must be hauled away,
the average commercial dump truck can carry up to 18 cubic yards of material.
That’s 55,556 truck loads that will be hauled away and dumped near the dam ...”
That’s a LOT of debris. Essentially, that’s the rock and concrete that the river cut away. I suspect that there’s some silt there, but a lot of it went downstream.