Posted on 02/12/2017 4:26:47 PM PST by janetjanet998
Edited on 02/12/2017 9:33:58 PM PST by Admin Moderator. [history]
The Oroville Dam is the highest in the nation.
In contrast to post image 1,320 the "Crest" is sizable, indicating a different condition than the "balanced" flow. Again, this may be from the inlet turbulence.
This image shows a lower water view of the front of the Main Spillway Weir.
You can see the vegetation (bush/tree) locations. The dark color is from a grassy covering. What is also of note is the wood debris laying on top of the other side inlet above the concrete. This debris matches the images that another engineering forum was debating as to what the material was (i.e. was it scoured erosion coloration, etc). This material was partially submerged from the inlet flow hydraulics. Yet it found an "eddy" where the material clustered together from the turbulent inflow.
The good news is that the berm itself does not seem to have experienced much scouring - other than the small surface erosion to aggregate material.
Obviously with the auxiliary spillway being much lower than the top of the dam, it would also prevent a build-up of pressure on the dam just with the water overflowing it.
At the same meeting I mentioned the “emergency” spillway, and another person (also an engineer that works with dams) quickly corrected me and said “We use the term auxiliary spillway.”
I'm sure they have their reasons for the nomenclature - but in this case, seeing as it is the first time since it was built in 1968 that water has gone over the top, this spillway could be properly called an “emergency spillway”!)
Here’s an article on some of the history of the auxiliary spillway, and concerns on it’s construction. Of course 14 years after they were raised, they just now cut the powerlines in anticipation of the towers failing:
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Many groups knew that, if the reservoir were ever hit by a major flood, water toppling over the emergency spillway would cause serious erosion. In 2002, the Yuba County Water Agency which owns transmission lines and other infrastructure in the area highlighted these concerns in a technical memorandum.
The discharge area below the emergency spillway is not armored, and extensive erosion would take place if the emergency spillway were used, the memo stated. The spillway road and possibly high voltage transmission towers would be impacted.
Read more here: http://www.sacbee.com/latest-news/article132528514.html#storylink=cpy
Here is the significant (some noted as "car sized") bubbles that were surfacing in front of the Emergency Spillway. The equivalent water displacement for these sized & number of "bubbles" indicates a penetrating flow. Where to has not been discussed by authorities other than unconfirmed reports of "leaks" (scanner traffic). Maggief has more info on the "reports" in some of her excellent detective work.
It would be interesting to see a video of that, to see if they are in fact bubbles. There are no ripples from any prior bubbles, and the camera just so happened to be here when the bubbles appeared. Maybe they’re just reflections. Need video.
The auxiliary spillway seems to been a perfunctory effort. It will only be used during a high water event, the very worst time to be pouring water on bare earth (as if there is a good time). They could have at least hardened the area out to the crest of the hill.
http://www.sacbee.com/news/local/transportation/back-seat-driver/article133485154.html
Mass chaos of Oroville evacuation prompts worry over exit strategy
http://www.sacbee.com/news/state/california/water-and-drought/article133326709.html
Oroville Dam: Spillway releases dialed back to relieve pressure on downstream levees, repair power plant
150,000 cubic yards of debris stand in the way of Oroville Dam’s hydroelectric plant restart
https://www.youtube.com/watch?v=Z8rbYVhM7cU&app=desktop
Lake Oroville Spillway blowout footage 2/17/17
Published on Feb 17, 2017
Some awesome video from the base of the spillway and still shots of the Excavators being assembled at the base to clear the sediment buildup in the Diversion channel..
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Officials may operate controlled spillway for first time since 1997 - Lake Don Pedro
Turlock Irrigation District officials may operate its controlled spillway Monday or Tuesday for the first time in two decades.
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http://www.latimes.com/local/lanow/la-me-storm-los-angeles-20170217-story.html
Major flooding, mudslides and deadly winds as biggest storm in years barrels into L.A. area
https://twitter.com/abc7robmcmillan/status/832815027849551872/video/1
Rob McMillanVerified account
@abc7robmcmillan
INCREDIBLE VIDEO: part of SB I-15 is washed away; fire engine tumbles off the side; fortunately no one hurt
8:52 PM - 17 Feb 2017 from Rancho Cucamonga, CA
At the last video I saw before the water began to recede, there were a couple of spots below the emergency spillway, near the main spillway that shows streams of water coming out like fire hoses. The impression I had was that there were two streams of water, under pressure working their way beneath the emergency spillway.
I agree they are withholding data from the public, but I would expect that examination on the lake side of the spillway would reveal where water was escaping. They can't afford to ever let the water get this high again. Northern California dodged a bullet.
Tin foil hat?
https://www.youtube.com/watch?v=0j_qxZGPbEI&feature=youtu.be
What Is Causing This Radar Anomaly At Oroville Dam In California
>>It would be interesting to see a video of that, to see if they are in fact bubbles.<<
I watched the video. I saw the bubbles coming up and bursting. I captured some of the video into images (this is one of them). I’d have to search for the video source if it is online still.
Not reflections.
What was interesting is the helicopter camera operator was in a wide angle view of the whole dam. Then he saw these huge bubbles coming up. That is when the operator zoomed in to this view. So they too saw the action.
I’ll take your word for it.
Very cool!
http://www.sacbee.com/news/local/article133545764.html
Check out this interactive 3D model of Oroville Dam
OROVILLE DAM master model for 3D printing by EOSGIS on Sketchfab
Want to get a great perspective of the Oroville Dam and surrounding areas? Below is a 3D model that will let you zoom around and remember the main spillway as it was before the huge hole emerged.
To zoom, scroll or pinch. To pan, right-click and drag or use two fingers to drag on touch devices.
(at link)
That first link is interesting. Evac a success? Wow. Q: Was contraflow used? If not, why not? And is Hwy 70 an Interstate? If not, why the heck should federal taxpayers get stuck with a $320 mil plus tab for expanding it. That’s CA’s problem.
That’s so cool...great perspective.
“This enlarged image shows trees growing in the berm/embankment that what looks like a concrete wall that joins to the upside down “J” of the curved “approach wall” inlet.”
Comparing this image with the image you posted in #1320 showing the turbulence before the spillway gate, it appears to me that the “upside down J” approach wall is gone, and may have collapsed.
The concrete wall that joined it remains, and the earth that abutted it on the near side has eroded away allowing water to flow on both sides of it, but at least two of the trees remain.
If true, could this be the cause of the turbulence you circled in #1320?
Thanks for all the pics and the info! Q: In that pic, it looks like one side of the spillway, the left side, is lower than the other? Is that the case?
>>Q: In that pic, it looks like one side of the spillway, the left side, is lower than the other? Is that the case?<<
No there is no tilting.
This “crest peak” may look as an illusion as the water has a natural shift in the sluice jetting. However, in this large “Crest” peaking, it is most likely from an asymmetrical input flow from the turbulence in front of the Weir inlet.
Got to have funds to feed sanctuary cities, lavish pensions, and railroads to nowhere. Can’t be wasting money on roads.
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