Apparently, The failure of the concrete spillway at the dam has been getting worse, and the volume of water that was diverted to an aux. spillway is also putting that in danger of failure, also. Here is a link to the story @ http://www.breitbart.com/california/2017/02/12/emergency-evacuations-ordered-oroville-dam-spillway-fails/
Linked story has photos of dam and failing area. The article mentions that the threat is to downstream of the dam: FTA “…The Feather River flows south into the Sacramento River. Flooding could potentially affect the Sacramento River and surrounding areas…”
"Update: A flash flood warning has been issued for significant parts of Butte County. The Butte County Sheriff has issued a warning: “This is NOT a drill.”
Not being familiar with the area and the terraine, BUt I remember reading about it while it was under construction in the 1960’s. The Southern Pacific RR was involved ( I think they were hauling in materials to build the dam(?). The article mentions that the water in the dam is ‘normally’ about 700’ above sea level, but due to the rains and infeed to the lake, it is now about 900’ above sea level. They seem to indicate that so far the only failure is in the area of the regular spillway and the auxillary spilway.
Major flooding would effect Sacramento area, quite a bit of agricultural activities(?) and I think the Ca. Railroad Museum? It seems like a potentially, very dangerous situation. Maybe some local Posters can advise of the situation.