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  1. samfriday

    samfriday New Member

    There is a user on youtube posting videos daily showing the work progress on the upper section. Search for the username Alan Kuentz. He says that the approximate distance is 2.45 miles from his location to the spillway. The footage of the machinery is not very close up, he says it's on the optical limits of his camera. A pity his camera doesn't have a higher zoom capability as it is a very good angle. The footage does show two pylons on the left hand side of the spillway. Any other comments on the footage?


    Source: https://www.youtube.com/watch?v=wD7WzYVW4iU
     
    Last edited by a moderator: Feb 16, 2017
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  2. Mick West

    Mick West Administrator Staff Member

    Moderation Note Please don't post unsourced rumors. We do not want to spread misinformation.
     
  3. SeanT

    SeanT Member

  4. A. Hunter

    A. Hunter New Member

    Some new pictures have been uploaded onto the CA DWR site (mostly construction work on e-spillway) but no pics of the main spillway/waterfall yet. Will continue to check news outlets and various sources to see if there are any new images.

    Source: http://pixel-ca-dwr.photoshelter.co...QU/DK-Oro-Spillway-damage-4203-02-15-2017-jpg

    Edit: The DWR pictures uploaded today are from yesterday, 2/15/17.
     
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  5. SeanT

    SeanT Member

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  6. A. Hunter

    A. Hunter New Member

    At 12 pm, flow is 90,000 cfs. According to the DWR press conference, they plan to lower spillway flow to 80,000 cfs and hold. They do not expect further erosion of main spillway.

    ORO CFS FLOW 2017-02-16 at 12.21.47 PM.

    Source: http://cdec.water.ca.gov/cgi-progs/queryF?s=ORO
     
  7. Junkie

    Junkie New Member

    The pictures of the entrance to the spillway appear to show unlined reasonably competent (grey) rock. With a lower water level, the same flow rate would require a higher velocity. It sounds like they're worried about erosion to the inlet of the spillway if they keep up 100k flow rate. I imagine debris from the erosion process could potentially damage the gates as well (I'm not sure what, if anything, they have to prevent logs from impacting but rocks are much harder).

    If they're confident they have enough storage capacity for what's coming, I can see why they're decreasing the flow rate. No need to cause even more damage.
     
  8. Cesar

    Cesar New Member

    Can someone please explain why erosion, due to upcoming rain, is not more of a concern for the newly formed cliffs near the mouth of the spillway? Wouldn't shifting soil in that area be a major concern? What is preventing that from happening?
     
  9. Junkie

    Junkie New Member

    It appears that the soil and less competent rock has been eroded away from that area, and that all that remains is reasonably competent rock which won't erode quickly.

    It doesn't sound like they expect to increase discharge rates any time soon, so I don't see why erosion there would increase.
     
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  10. Mick West

    Mick West Administrator Staff Member

    The concern would be with the "cliffs" in the waterfall region, the lower down ones are not too important. The most important one would be by the transmission towers (although they are going to move them anyway).

    20170216-125010-o2ut3.

    Given the pounding and spray already, I suspect that some rain isn't going to do much damage. The hillside is relatively stable and has been there for decades (if not thousands of years). Maybe a bit more surface erosion.
     
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  11. stuart little

    stuart little New Member

    just wanted to note on the drainage system flowing into the chute of the main spillway. after the hole formed and the sidewalls blew out... all the upper drains were still running but everything below the break was no longer draining.. not sure what that means.. or the relevance but throwing it out. on closer inspection i see some trickles through the drains from the left side of the photo.. kayaker's right
    [​IMG]
     
  12. KenMH

    KenMH Member

    In this video of a previous release from the spillway it shows the drains start flowing about there, apparently that is normal for this spillway.


    Source: https://www.youtube.com/watch?v=XsS_93cOJ7k

    Something else about that video, how the water aerates as it drops to the steeper slope, cavitation ripped the concrete apart seems possible. Bubbles in a flow bursting release energy and are known to break down rock surfaces. I think someone was posting a more detailed and scientific viewpoint along those lines. this video might support that.
     
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    1. Have you seen any photos from today of the main spillway breach? I had a quick look on the CA DOW website, and it appears that all photos are still from yesterday or earlier...
     
  13. You might be right. It is hard to tell if water is coming out of the drains, but it is certainly not gushing out. The stains could be from earlier (rainstorm or previous rainy season?).
     
  14. A. Hunter

    A. Hunter New Member

    I've found a gallery of pictures taken by a photographer, Bill Husa, for the Chico Enterprise-Record today.


    Source: https://twitter.com/billhusa1/status/832394438936711170


    Here is a screenshot of the top of the main spillway. Haven't found a good, clear shot of the new ravine. But will keep digging.

    Image credit-Bill Husa Enterprise-Record 2:16:17.

    Source: http://photos.orovillemr.com/2017/02/17/photos-oroville-updates-thursday-2-16-2017/#22
     
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  15. Mick West

    Mick West Administrator Staff Member

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  16. Thanks! Unfortunately it looks like we have lost some ground (literally) on the left hand side of the spill way in the last 24 hours (as compared to photos from Feb. 15)..., and to my untrained eye the exposed underburden looks like it might not be "competent" at the newly exposed cut... **I may have jumped the gun on losing ground since yesterday as it is hard to tell where the extent of the erosion is on the Feb. 16th photo**
    I also noticed appreciable running water just outside the left hand wall on the Feb. 16 photo, at the top of the break and about the level of the deck. This might help explain the issue of the drains.
     
    Last edited: Feb 16, 2017
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  17. Mick West

    Mick West Administrator Staff Member

    Here's a contrast enhanced section of both photos (not lined up here, this is just to compare the material)

    20170216-175927-vbjtp.


    20170216-175832-cy4qh.
     
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  18. wrorke

    wrorke New Member

    Is that flow out of a broken drainpipe immediately behind the sidewall? (Relevant to discussion of flow through sidewall outlets.)
     
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  19. SeanT

    SeanT Member

  20. Possibly. When I first noticed the water (post #58) that thought crossed my mind as well. Hard to tell from this photo, and I haven't seen any indication of a sloped drain pipe in any other photo.
     
  21. CRM114

    CRM114 Member

    It's possible, but watch as the rain does come. If there are any vertical fractures or tension cracks behind the face and somewhat parallel to it, they can fill up and the water acts as a hydraulic wedge that can peel off a chunk of the face.
     
  22. KenMH

    KenMH Member

    CRM114 posted this photo in the other 'how they work' thread,
    [​IMG]
    it appears to show the terminating end of the drain and correlates pretty well with the image in this thread to indicate the pipes come out nearly horizontal and terminate, if that is a broken pipe and water flowing on the right side of the second image in your post (that Mick posted earlier).
     
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  23. JustCurious

    JustCurious New Member

    Last edited: Feb 16, 2017
  24. A. Hunter

    A. Hunter New Member

    Is this the flow you are referring to? 20170216-175832-cy4qh.

    Could this be part of the under drainage system? Hard to tell from this photo.
     
  25. It was the flow I was referring to in my above post #58 (last two sentences).
     
    Last edited: Feb 17, 2017
  26. KenMH

    KenMH Member

    yep thats the flow I was referring to, if it is flow.
     
  27. Mick West

    Mick West Administrator Staff Member

    This?
    20170216-215922-fxhcu.
     
  28. Ecomorphologist

    Ecomorphologist New Member

    Close inspection of Mick West's photos in #59 shows that there has unequivocally been some loss of material from the scarp between Feb. 9 and Feb. 16, and that the mode of movement is geotechnical slumping, not just plain particle-by-particle erosion as in a standard head cut in a channel. Either that material is fill, or it is weathered rock that is so extremely weathered that its mode of failure looks exactly like the textbook diagrams of soil slumps. (My point in a post that related mostly to the drains and has been moved to that offspring thread.) Looking at the high-res photo, I don't see any discontinuity in the slope, soil color, or vegetation that provides any reassurance that something might arrest the process of slumping continuing up the slope for some additional distance. We'll like see that over the course of upcoming storms. However, I still think the spillway chute might possibly remain intact, if it's closely attached to more competent material. The photos of the side walls suspended high in the air, but almost not deformed at all (#64), suggests that it's pretty stout reinforced concrete construction. Absent a failure of under drains (discussed elsewhere) that caused the original failure, we could see loss of a lot of the left side slope but the spillway chute remain mostly intact and functional.
     
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  29. Mick West

    Mick West Administrator Staff Member

    I think it was largely in the first few days though. Here's Feb 11
    http://pixel-ca-dwr.photoshelter.co...mDTx48Y/I0000_kQrW2SJ8ME/FL-Oroville-1441-jpg

    Comparison:
    b. a.


    The loose material seems to have gone, but the top edge is relatively unchanged.
     
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  30. Scott Gates

    Scott Gates Active Member

    Spillway construction notes - page 133

     
    Last edited by a moderator: Feb 17, 2017
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  31. Paul Bogdanich

    Paul Bogdanich New Member

    As of this morning (02-17-17) outflows have been reduced to 80,000 cfs, inflows averaging about 27,400 cfs and the lake level at 861.18 feet (901 is the emergency spillway action) and falling at about three an a half inches an hour. Still no current pictures I see. I kind of figured as much. The state doesn't like to share potentially embarrassing information irrespective of how relevant it may be. Probably an executive order to stop it with the pictures and a trip to visit Bradley Manning for any violators (sarcasm people, just barely but sarcasm).
     
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  32. No.
    Sorry for the confusion. I have edited my post #67 to clarify.
     
  33. SeanT

    SeanT Member

    Last edited: Feb 17, 2017
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  34. I've got mixed feelings about the lack of recent photos in the areas that concern me most (extent of spill way erosion and newly formed ravine on left hand side). The authorities are clearly working their butts off to keep the reservoir fully contained, and from I can tell they are doing a great job. Will they be successful in the long term remains to be seen, but I hope so. The last thing I would want to have on their priority list is to snap some photos for armchair experts such as myself. That being said, it is likely that this blog is monitored by the authorities, and they are likely to benefit from the insights offered herein, and the more info they provide us the better those insights will be.
     
    Last edited: Feb 17, 2017
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  35. Thanks for posting this. The ravine is clearly increasing in size and in flow, as is the bypass flow just to the left of the left channel wall. I think it is likely that most of the loose soil and loose rock between these to streams is in jeopardy. Some of this will make its way to the river, and will complicate (add to) the dredging operations. It may even be a safety issue for the dredging crews. Not sure if this will impact the extent of the upstream spill way erosion up at the towers, or whether this will lead to further loss of general stability on the hillside given the ongoing deluge (rain). Apparently still no photos posted of the spill way at the towers, although from the news conference I believe they are saying no further upstream migration of erosion.
     
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  36. SeanT

    SeanT Member

    It looks to me like the stream starts above the break in the spillway. DWR (Croyle) was asked about this during press conference and said they weren't aware of it.
     
    Last edited: Feb 17, 2017
  37. Paul Bogdanich

    Paul Bogdanich New Member

    "from the news conference I believe they are saying no further upstream migration of erosion."

    I have a hard time believing that. Venturi erosion should have taken at least a few feet to a section of the spillway wall away by now.
     
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  38. When you say "It looks to me like the stream starts above the break in the spillway" is there a photo that you are referring to?
     
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  39. Mick West

    Mick West Administrator Staff Member

    What are you basing that on?

    I don't see why that would be a given. Consider the most energetic part of a regular release - the flow around and over the detentes (big tooth-like things at the bottom).
    20170217-130309-p9mq7.
    Source: http://www.chicoer.com/article/NA/20170210/NEWS/170219971#

    Yes, a patch was needed after a large release some time in the past. But just one spot.
     
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