From the ChicoER News:
Emergency spillway could fail; evacuations ordered
Evacuations were ordered Sunday afternoon after erosion raised fears the emergency spillway at Oroville Dam could fail.
An evacuation information center has been set up to answer questions: 530-872-5951.
The Department of Water Resources said about 3 p.m. Sunday a headcut appeared in the soil downhill from the emergency spillway, and appeared to be spreading upward toward the structure.
If the spillway structure were undercut by the enlarging hole, it could fail, and the water behind that barrier would come down the hill into the Diversion Pool and down the Feather River.
With that possibility, and “an abundance of caution,” Sheriff Kory Honea ordered the evacuation of downtown Oroville and other low-lying areas downstream. Yuba and Sutter counties followed suit.
The bridges across the Feather River between Marysville and Yuba City were closed.
The dams regular spillway was built 50 years ago and failed during normal operation. It will be some time until the actual cause is determined. The Oroville Dam is the tallest dam in the United States.
The ChicoER also published this damning editorial:
Editorial: Oroville Dam crisis a failure on many levels
History was made in Butte County this week, and it isn’t the good kind of history either.
A 50-year-old spillway broke in the middle on Tuesday next to Oroville Dam and the modern equivalent of hydraulic mining happened Saturday when water topped the north side of the dam face and down an emergency spillway.
To call it an emergency spillway is to vastly oversell it. It is not a structure. It is a ravine that until this week was filled with trees, rocks and dirt.
Once dam operators figured out that the lake’s inflow was more than the crumbling spillway would allow as an outflow, crews scrambled to clear a path for the water from the inevitable overflow.
Using rocks and cement, they tried to steer a path away from the damaged spillway.
The overflow started Saturday morning just after 8 a.m. By 11 a.m., the stream was large. With tributaries still running high from last week’s storms, the inflow to the lake was 84,000 cubic-feet per second. The spillway could only handle 55,000 cfs.
Getting to the point:
For the state, Lake Oroville is a source of cheap power and cheap water for people downstream. From Butte County’s point of view, it has been a draw on resources, from lost property taxes to money spent on public safety and infrastructure. For too long, our area has received the worst end of this deal.
The reservoir’s water and power have been a cash cow for the state and obviously the state didn’t reinvest on inspections, maintenance and contingency plans.
The DWR can argue all day that this was an unforeseen and unpreventable act of nature, but that has to be part of the lesson. When you have a spillway (and a dam) that’s a half-century old, you’d better pay attention to the maintenance.
Much more at the site - the state of California was making a lot of money from the electrical power generation and potable water sales but they were not reinvesting this revenue back into upgrades and maintenence. Now the butcher's bill has come due - the next six months or so will be interesting.
Here is a somewhat dystopian video:
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