Dam Trouble

Just remember this situation the next time the water guys start talking about building yet more dams, like at Sites and Temperance Flat.

you don't have any role in this, of course, except to be a public scold...

There's only so much money for everything to go around and politics play a huge part of it especially when;

Oroville has, apparently, had listed deficiencies that went unaddressed for up to 12 years.

The rainy season commenced on the 8th of November, and for four weeks, with scarcely any intermission, the rain continued to fall very gently in San Francisco, but in heavy showers in the interior. According to the statement of a Grass Valley paper, nine inches of rain fell there in thirty-six hours on the 7th and 8th inst. Whether, it is possible that so much rain could fall in thirty-six hours I will not decide; but it is certain that, the amount was great, for the next day the river-beds were full almost to the hilltops. The North Fork of the American River at Auburn rose thirty-five feet, and in many other mountain streams the rise was almost as great. On the 9th the flood reached the low land of the Sacramento Valley.

"[1]Back to the dam, any experts here want to chime in on the subject as to why the emergency spillway has nothing but dirt underneath it...

[2]Also, if a big sinkhole collapsed under the main spillway does that mean water has been leaking under there for a while?"

2- not necessarily. Could be they used precast concrete panels without sealing joints, or had cracking that got big enough to leak through. Any of a bunch of reasons that the failure could have occurred.

1- it looks to me like the issue is the pool at the end of the spillway - the turbulence eating out under the end of the spillway. I don't know what design standards were in the 1960's when this was built, but it is possible they don't have sufficient (size & amount) rock to break up the energy from the water at the end of the emergency spillway.