Here is part of the evidence supporting a ‘run for your life’ evacuation order. Photographs in the ‘gallery’ show the top of the emergency spillway and illustrates the erosion with 1.5 foot depth of flow across the weir. The assumed solid bedrock of the spillway has revealed poor strength—the weir as cast in place with no anchorage to the underlying rock is as deep as 40 feet. No core testing was performed upon the rock—appears as an original design flaw based on the assumption of solid rock which has been shown as mistaken.
http://www.latimes.com/local/california/la-me-oroville-spillway-failure-20170216-story.html
#39 The concrete was just plopped on the rock....
No spillway either, just the dirt and trees they mentioned plus the power lines across the area.
Even I know you gotta do better then that!