Emergency: California’s Oroville Dam Spillway Near Failure, Evacuations Ordered

To: Jim 0216; rodguy911; LucyT; KC Burke

“Oro” is Spanish word for “gold”

2,081 posted on 03/01/2017 10:31:00 AM PST by WildHighlander57 ((WildHighlander57, returning after lurking since 2000)

To: WildHighlander57; rodguy911; LucyT; KC Burke

Those barges could strike at rich but what a waste if it went to government. Anyway this gold angle could get interesting

2,082 posted on 03/01/2017 10:51:31 AM PST by Jim W N

New images added at the beginning of the series. They’re really attacking that pile of debris/rubble at the bottom of the spillway.

https://pixel-ca-dwr.photoshelter.com/galleries/C0000OxvlgXg3yfg/G00003YCcmDTx48Y/I0000Hz3yG1RSfDI/BSB-7817

2,083 posted on 03/01/2017 11:55:32 AM PST by meyer (The Constitution says what it says, and it doesn't say what it doesn't say.)

Related to those picture, the two issues I see and posted earlier are...

1) The Main Spillway damage is so gargantuan that until the rainy season is over, if the Main Spillway is needed, it will continue to move earth and rock into the middle of the river below and back it up into the power plant. I mean even remedial repair looks like it would take weeks or months to fix that problem. I don’t know exactly what they plan to do in the next seven days. I don’t know how long a permanent fix would take.

2) The Emergency Spillway looks more threatening to cause a catastrophic emptying of the reservoir and flooding from its failure. Maybe the whole Emergency Spillway design needs an overhaul including the un-anchored upside-down half shell at the top. Have no idea how long that could take.

Is it possible that the time to do the job right on these spillways could take more that one summer season? If so, couldn’t that change the priorities of what the do first to reasonably hold off a problem next winter and finish the job the following summer?

2,084 posted on 03/01/2017 12:03:03 PM PST by Jim W N

To: Repeal The 17th

Have to wonder about the condition of that lake side floor to the main spillway gates. Had to be some serious hydraulics there, too...

2,085 posted on 03/01/2017 12:14:00 PM PST by polymuser (There's a yuuuge basket of deportables.)

All that activity in that small of space is impressive. Hope they have a good safety culture that is an accident waiting to happen.

2,086 posted on 03/01/2017 12:18:21 PM PST by mad_as_he$$ ("It's a war against humanity!" Donald J. Trump)

To: Repeal The 17th

Wonder how they got that many little people on one crew. ;-)

2,087 posted on 03/01/2017 12:19:54 PM PST by mad_as_he$$ ("It's a war against humanity!" Donald J. Trump)

I think that they have the trucks working basically a loop where they get loaded, then move on and out to the dump area. Wherever that is.

2,088 posted on 03/01/2017 12:30:18 PM PST by meyer (The Constitution says what it says, and it doesn't say what it doesn't say.)

They come in a little box with the ant hill already assembled.

2,089 posted on 03/01/2017 12:31:41 PM PST by Jim W N

CAT’s PR department will have field day...

this is far from over....pattern turns more active/wet again soon

and huge snowpack about to start melting

there is still some water flowing out.....and it may be slowly eroding under the ledge of the main spillway similar to the hillside of the ES spillway? When the water was on the flow of the water was pushing it out but now it falling straight down

2,090 posted on 03/01/2017 12:33:45 PM PST by janetjanet998

2,091 posted on 03/01/2017 12:55:15 PM PST by mad_as_he$$ ("It's a war against humanity!" Donald J. Trump)

To: Grampa Dave; Jim 0216; maggief; Mariner; Ray76; daisy12; janetjanet998; LucyT; Yaelle; SE Mom; ...

>>Years of Warnings at Blowout Area? Missing drain water/slabs being repeatedly repaired at leakage..

Where's the water? Apparently there were years of pre-warning signs [2] of an anomaly at the area where the main spillway failed. It is missing water. The main spillway has drain pipes under the concrete slabs that collect any penetrating sub-slab water and route it up into drain outlets in the concrete sidewalls.

btw- Scott Cahill, a dam expert, notes that a well designed/sealed/maintained spillway would have very little drain water during spillway operation [3] (should not be "jets of water" - these "jets" reveal how much volume and pressure the water may "scour" underneath the spillway slabs and substructure rock).

You can see water from these drains from 2013 and in 2017 (just prior to the "blowout failure"). Critically, the "blowout area" has missing water from the drain outlets. This is a critical indicator as a non-presence of waterflow indicates that water is not being collected (possible drain pipe failure) OR the water is not entering the drain either by an improper gravel layer emplacement OR the water has found a deeper flow path (or combinations of all three). Water has been observed to well up from under the main spillway slabs at the area of the blowout failure. The 2013 image reveals this. The 2017 image also shows a "defect" chip in a seam in the main spillway slab (at/near the blowout failure area). This 2017 picture was taken in the last week of Jan 2017, just before the Feb flooding & main spillway failure. Having this defect present would have likely initiated very damaging cavitation erosion from spillway flow (jackhammer effect on the concrete). Likely a precursor to the "missing water" substructure penetration = (i.e. potential sub-structure erosion deep under the slabs or undermining the "backfill concrete" chunks [1]).

= = reference notes:

1. Stagnation Pressure' as described by the Bureau of Reclamation: "Stagnation pressure refers to two conditions that can result in damage and/or failure of the spillway: (1) High velocity, high pressure flows enter cracks or open joints in the spillway flow surface (such as a chute), which results in uplift pressure that lifts (displaces) portions of the spillway conveyance feature; and (2) High velocity, high pressure flows enter the foundation through cracks or open joints in the spillway flow surface, which results in internal erosion of the foundation and loss of support of portions of the spillway conveyance feature [26]."

2. Alarms Raised Years Ago About Risks of Oroville Dam's Spillways:

..excerpt: "The cratering of the main spillway — which spiraled into the current crisis in Butte County — occurred in a spot where cracks and other defects had been found repeatedly since 2009, said Robert Bea, a professor emeritus and engineering expert at UC Berkeley." “My God, we had evidence that there was trouble going back to 2008, 2009,” said Bea, who at The Chronicle’s request reviewed 14 dam inspections from 2008 to 2016 conducted by the Division of Safety of Dams, which is part of the Department of Water Resources.

“Yes, they had detected the defects (in the main spillway) and yes, they had put into gear remedial measures,” Bea said. “Were those repairs sufficient? No. The result was a breach.”

.. end excerpt

http://www.govtech.com/em/disaster/Alarms-raised-years-ago-about-risks-of-Oroville-Dams-spillways.html

3. One highly respect dam design expert, Scott Cahill, had some very enlightening information regarding Oroville's main spillway & issues linked to his extensive knowledge on dam failures. Three of the key issues he noted in detail was (1) thorough & expert level maintenance (2) the Oroville main spillway had too high of an underflow of water beneath the concrete [as he noted by the amount, volume, and velocity of the "jetting" underdrains - this is a significant issue to address to prevent erosion scouring and sub-spillway pressurized leakage] - [i.e. this was an "early warning" that should have been taken action upon] (3) the original construction MUST be thorough on its bedrock/concrete and anchoring stability.

Workers in 2013 at pre-failure blowout area - notice the missing drain flow (red circle) and the notable upwelling of water in the main spillway.

Same missing waterflow in drain near pre-failure blowout area. notice the defect in the concrete slab seam at/near the pre-failure blowout area.

2,092 posted on 03/01/2017 1:12:07 PM PST by EarthResearcher333

To: carriage_hill

.......and don’t forget those high priority sex change operations for prisoners!

2,093 posted on 03/01/2017 1:14:04 PM PST by Cen-Tejas (it's the debt bomb stupid)

To: EarthResearcher333

Here's a sketch I made of how I see the drainage system as built. Over the past couple of weeks, I've spent a lot of time over @ Metabunk, discussing the drains with several other technical types. It's not to scale, and I believe each collection along the wall footing served as many as 10 underslab drains.

One of the things we learned was that the drainage system was fabricated using vitrified clay pipe (VCP). It is similar to glazed pottery and is rather fragile. If the plugged drains as shown in the photo, well, that water was going somewhere. I suspect it washed out the fill alongside the outside wall, then the washout progressed up underneath the wall and main slab.

2,094 posted on 03/01/2017 2:15:50 PM PST by abb ("News reporting is too important to be left to the journalists." Walter Abbott (1950 -))

Appreciate it, abb and EarthResearcher333.

Metabunk’s been a good resource for studying this situation and learning.

2,095 posted on 03/01/2017 2:58:02 PM PST by meyer (The Constitution says what it says, and it doesn't say what it doesn't say.)

Working in a coal mine
Going on down, down
Working in a coal mine
Oops, about to slip down
-
Lee Dorsey-Working In The Coal Mine(1966)
-

2,096 posted on 03/01/2017 3:18:05 PM PST by Repeal The 17th (I was conceived in liberty, how about you?)

To: Repeal The 17th

2,097 posted on 03/01/2017 3:30:29 PM PST by Jim W N

To: Repeal The 17th

You load sixteen tons, what do you get
Another day older and deeper in debt
Saint Peter don’t you call me ‘cause I can’t go
I owe my soul to the company store
-
https://www.youtube.com/watch?v=zUpTJg2EBpw

2,098 posted on 03/01/2017 3:50:01 PM PST by Repeal The 17th (I was conceived in liberty, how about you?)

To: Repeal The 17th

I remember that song!

2,099 posted on 03/01/2017 3:52:34 PM PST by meyer (The Constitution says what it says, and it doesn't say what it doesn't say.)

2,100 posted on 03/01/2017 4:03:34 PM PST by meyer (The Constitution says what it says, and it doesn't say what it doesn't say.)

FreeRepublic, LLC, PO BOX 9771, FRESNO, CA 93794

The California Department of Water Resources issued a sudden evacuation order shortly before 5 p.m. Sunday for residents near the Oroville Dam in northern California, warning that the dam’s emergency spillway would fail in the next 60 minutes.