Lake Oroville emergency spillway expected to fail

[SternWake]

Not a dam failure,  the original spillway has been heavily damaged ion the last week, the emergency spillway has been employed and the erosion is getting to the point where the emergency spillsway is precicted to fail.

Evacuation orders are in place.

Repeat this is not an expected failure of the whole dam which would be catastrophic.

At least at this point.

http://www.kcra.com/nowcast

 

[GotSmart]

I had some property above Oroville.  If that goes, Not good at all!

http://fox40.com/2017/02/12/evacuat...s-situation-developing-at-emergency-spillway/

 

[BobBski]

Trying to manipulate Mother Nature can sometimes be costly. Hope everyone gets out of this ok. I was just reading about this...one of the stories was about the evacuation of salmon from the hatchery.

 

[SternWake]

Another Atmospheric river type of rain system is lining up for later in the week.

Looks like 5 separate low pressure systems will slam into Northern California starting on Thursday.

http://www.atmos.washington.edu/~ovens/loops/wxloop.cgi?gfs_pcpn_slp_thkn+///6

Considering it has not rained in a few days there, yet the water levels still rose to the highest level ever recorded, despite them opening up the regular spill way as much as they can......

This could get interesting. Good time to not be a property owner in the area, and on Wheels.

Looks like 10s of thousands are being evacuated and they will be opening up the opposite lanes of traffic to reduce the traffic jams.

Local news here in Southern California, devoted about 10 seconds to this developing emergency situation, The Human fluff stories must run!!

 

[highdesertranger]

it's amazing, last year the reservoir behind that dam was at 30% approximately. this year it's overflowing. Lake Shasta is almost full too. we are out of the drought. highdesertranger

 

[SternWake]

Only Northern California is considered out of the drought.

Southern Areas are in moderate, and severe, and a few sections of 'extreme'

http://www.latimes.com/local/lanow/la-me-g-california-drought-map-htmlstory.html

 

[ColdBrook]

I don't know where to post this but I read on another Rving group that they are evacuating everyone south of the Oroville Dam in California.  I pray anyone camping or boondocking in that area got the message to evacuate immediately.   Includes the Yuba area, so please contact anyone who might be in the path of that dam to evacuate immediately.

 

[DannyB1954]

They can form up and pour concrete underwater, I don't know why they can't divert the water on the spillway long enough to patch the bad spot.

 

[SternWake]

Because 100,000 cubic feet of water is rushing past the damaged concrete spillway ever second, at high speed. To divert the water elsewhere means diverting it to the earthen emergency spillway which is now also extremely compromised. The only other path for the water to take is through the hydroelectric part, or through the dam itself.

While the concrete spillway is basically a write off at this point, the fear is that the emergency earthen spillway, that only has a small area around the lip that is reenforced by concrete, has been overflowing, and the water has been eating under the thinner concrete lip and running the 800 vertical feet down into the river below chewing up and eroding the hillside.

The fear is that the concrete lipped portion of this emergency spillway would collapse, and then instead of 1.5 feet thickness of water spilling over it, it would be 12 or 15 feet of water thickness pouring down the 800 vertical feet over muddy earth. This fear caused the evacuation, and it see,s they got lucky, so far.

I believe the plan is at first light is to use heavy transport helicopters and drop large cages of stone bulkwarks into the hole that is eating the underside of the emergency spillway and hoping to prevent its collapse.

The concrete spillway is basically total writeoff at this point, and the flow is now eating into the earth next to and under it., and into the earth under the emergency spillway. they were limiting the flow of water down the damaged concrete spillway to slowand limit the the damage to the concrete spillway, but once the earthen emergency spillway started to erode dangerously they said heck with trysing to save the concrete spill way and allowed 60% more flow down it, basically writing it off completely.

While it has not rained in a few days, today's spillover was caused by snow melt and was not predicted to reach the level it did. If they had known, I bet they would have opened the spigot earlier on the damaged concrete spillway sacrificing it, rather than trying to prevent its total destruction.

On thursday the rain starts again, and hopefully that is enough time for them to reenforce the emergency spillway's concretelip, so it does not crumble and allow 12 or 15 feet to just pour into the valley bottom 800 feet below.

I think this drama is just beginning, and hopefully it does not get as bad as it could. I am surprised it is not getting more attention from the media, But they seem preoccupied by whatever the insane evil cheeto tweets next.

 

[LeeRevell]

Hard to understand folks living on the low side of a dam. I know, folks say that about Florida and hurricanes, too. Yada, yada.
But any dam will eventually be overtopped and cause a flood, or even worse fail completely. River bottom land is very fertile and tempting, but it has it's dangers.
Here, there is a smaller dam on a river about ten miles down the highway from my property. Every so often, storm waters bloat the river, the dam overflows or must open the floodgates, and the same families immediately below it get flooded. Again, and again. The county bails them out, again and again.

 

[DannyB1954]

  To divert the water elsewhere means diverting it to the earthen emergency spillway which is now also extremely compromised.  The only other path for the water to take is through the hydroelectric part, or through the dam itself.

I was thinking of diverting only a part of the regular spillway. Not sending the water somewhere else, but just enough to shield part of the hole in the spillway.  Just enough to repair the hole a little at a time. Once one section is patched, move the diverter over to the next bad section.
I am pretty good at figuring out simple solutions to complex problems. Unfortunately they would probably never work in reality.

 

[bullfrog]

In Eastern Kentucky people with flood insurance make a living out of rebuilding their the first floor of their 2 story house each year!

 

[SternWake]

They are talking about getting the level down far enough, then simply trying to mitigate the damage to the regular heavily damaged spillway.

The regular spillway looks to be completely destroyed on the bottom half.

They are not going to be able to effect any real repair until the Summer.

I believe the goal now is to shore up the Emergency spillway with canvas baggs filled with aggregate, in case the lake level exceeds 900 feet again, and to attempt to slow the inevitable destruction of the main spillway.

They cannot effect any repair on the main spillway until they drop the lake level, and shut off the flow. Right now 100,000 cubic feet per second of water are flowing down it.

 

[TrainChaser]

They are expecting a THREE-STORY wall of water! [This from today's news.]

 

[DuneElliot]

Hard to understand folks living on the low side of a dam.  I know, folks say that about Florida and hurricanes, too.  Yada, yada.
But any dam will eventually be overtopped and cause a flood, or even worse fail completely.  River bottom land is very fertile and tempting, but it has it's dangers.
Here, there is a smaller dam on a river about ten miles down the highway from my property.  Every so often, storm waters bloat the river, the dam overflows or must open the floodgates, and the same families immediately below it get flooded.  Again, and again.  The county bails them out, again and again.

Avoiding living below a dam is pretty tough...even I, in a tiny little town in the mountains of Wyoming, know of at least two mountain dams above me...pretty much everyone somehow lives on the low side of a dam.

 

[LeeRevell]

No mountains here. Flooding is much more limited when it happens. It is just sheer pigheadedness on these people's part. Plenty land available around the area, that doesn't flood. I made sure I bought on higher ground. If I get flooded, it is Biblical! My winter temps run several degrees warmer than low lying areas, so I tell people I live on a "volcanic ridge". ;-)

 

[ccbreder]

SternWake, we are looking at this from the east coast and don't see why it is such a problem.

 

[GotSmart]

Tell that to the 200,000 people evacuated, and the tens of millions of people that will be affected if the top half of the central valley is destroyed.   

BTW, there has not been one report of looting, shooting, or price gouging in that area.

 

[GotSmart]

FEMA has stepped up, and rock and gravel is being moved into place to shore up existing structures.  The whole Dam is built on bedrock, so it is doubtful that a catastrophic failure will occour.  

[font=Arial, sans-serif]After evaluating the erosion on the emergency spillway, a plan was put in place to prevent further erosion. Utilizing trucks and helicopters, crews moved large rocks and gravel to fill erosion on the emergency spillway. Department of Water Resources staff continues to inspect and evaluate the emergency and primary spillways for further erosion.[/font]

[font=Arial, sans-serif]Total discharges from the reservoir remain consistent with flood control releases at this time of year under these weather conditions. Department of Water Resources does not expect the discharge from the reservoir to exceed the capacity of any channel downstream.[/font]

http://www.lakeconews.com/index.php...ry-spillway-failure&catid=1:latest&Itemid=197

 

[TrainChaser]

This dam is the tallest one in the U.S.

Dumping concrete into it isn't going to help; yes, concrete will cure underwater, but it takes at least 28 days to cure, and I doubt that they have 28 days.

Nice to see someone using their head and opening up both sides of the freeway. That just doesn't happen much.

Here's what it looked like ahead of Katrina; note that the other side was virtually empty. The cars on the empty side were probably reporters: http://s186.photobucket.com/user/The_Macallan/media/Stuff/BugOut/FleeingFromKatrina.jpg.html

At least they're not ignoring it and telling everyone 'It will be fine -- don't worry'.