Oroville Dam Spillway Failure 'Expected'

 Water flows over the damaged main spillway at Lake Oroville and into the Feather River in Oroville, Calif., on Saturday. (Brian van der Brug / Los Angeles Times)

LA Times:

Residents of Oroville and nearby towns were ordered to immediately evacuate on Sunday afternoon after a “hazardous situation” developed involving an emergency spillway at the Oroville Dam.
The National Weather Service said the auxiliary spillway at the Oroville Dam was expected to fail by 5:45 p.m., which could send an “uncontrolled release of flood waters from Lake Oroville.”
Those in Oroville were asked to flee northward toward Chico. In Yuba County, those in the valley areas were urged to take routes to the east, south, or west.
“This is not a drill. This is not a drill. Repeat this is not a drill,” the National Weather Service said. Authorities urged residents to contact neighbors and family members and reach out to the elderly and assist them in evacuating.

The Butte County Sheriff’s Department and the state Department of Water Resources said the failure of the auxiliary spillway — a 1,700-foot-long hillside route — was caused by “severe erosion.”
The evacuations marked a dramatic turn of events at the nation’s tallest dam. For several days, officials have been trying to figure out how to get water out of Lake Oroville after the main spillway was damaged.
The emergency spillway had never been used before — and until the last few hours it seemed to be working well. Video from television helicopters showed water flowing into a parking lot next to the dam, with large flows going down both the damaged main spillway and the emergency spillway.
The water is flowing into the Feather River, which runs through downtown Oroville and other communities. Water levels were rising on the river.

Wow, that is very scary.  I'll follow up tomorrow.