Search results

  1. A

    Oroville Spillway Investigation and Repair

    Well, in truth, the image is a crop from a DWR photo, only the colored lines are the work of SweepLeader, but I read the entire report and kept seeing all these photos and concepts that had been built here through our discussions. I was humored - seems we at least have a professional who agrees...
  2. A

    Oroville Spillway Investigation and Repair

    The brown streaking is likely leakage from the damaged and now incomplete herringbone drains that would have connected further down the spillway. It is not surprising that they do not have a complete seal at the shotcrete/slab interface and any water that is trapped there would naturally find...
  3. A

    Oroville Spillway Investigation and Repair

    There is no pipe here - a zoom from a photo just after the initial spillway shutdown shows the large rock pile being used as a tool rest: Source: https://pixel-ca-dwr.photoshelter.com/galleries/C0000OxvlgXg3yfg/G00003YCcmDTx48Y/I0000e_s_NS5UuRM/FL-Oroville-7745-03-03-2017-jpg The applied...
  4. A

    Oroville Dam Spillway Failure

    Based on the post closure pictures - this prominent plume of brown appears to be originating at the downstream edge of the shotcrete application along the left edge. You can see in the post shutdown photo that the area has been undercut which is indicative of the impact point and churning due to...
  5. A

    Oroville Dam Spillway Failure

    You can see that there is significant flow down the left side (nearest) by looking at the bottom center right of the image I posted: This pipe, providing a temporary extension of the VCP longitudinal drain, covers only the last remaining section of herringbone drains on this side and is...
  6. A

    Oroville Dam Spillway Failure

    So, during the time the spillway was not in use - we saw photos and heard reports from DWR that they were doing a full review of the upper portion and repairing any possible cracks and voids. Review the most recently posted photos on the DWR pixel site such as this one...
  7. A

    Oroville Dam Drains in The Spillway Walls - How Do They Work?

    I agree that was what appears to be the original design intent. Here is why I don't believe that is how it was ultimately constructed: Such a position for the longitudinal drain would have made for unnecessarily complicated connections from the lateral "herringbone" drains into the collector...
  8. A

    Oroville Dam Drains in The Spillway Walls - How Do They Work?

    This picture has provided me with some great information about the arrangement and operation of the drains: https://pixel-ca-dwr.photoshelter.com/galleries/C0000OxvlgXg3yfg/G00003YCcmDTx48Y/I00006q7HWGbgJS8/FL-Oroville-8728-jpg From this I have zoomed and annotated the following image: Based...
  9. A

    Oroville Dam Spillway Failure

    New photos posted at the DWR site, including night work - appears they are filling in across the emergency spillway face with the grouted rip-rap. http://pixel-ca-dwr.photoshelter.com/galleries/C0000OxvlgXg3yfg/G00003YCcmDTx48Y/I0000UIZKGhtp2Ss/ZC-Night-Oro-Spillway-5-02-20-2017-jpg
  10. A

    Oroville Dam Drains in The Spillway Walls - How Do They Work?

    I think I found a remaining drain line in some of the early photos after the damage was discovered original image source: http://pixel-ca-dwr.photoshelter.com/galleries/C0000OxvlgXg3yfg/G00003YCcmDTx48Y/I0000kN9PORvuykE/KG-oro-spillway-damage-10060-jpg It exists on the SE side here: original...
  11. A

    Oroville Dam Spillway Failure

    Based on these new photos as well as the panorama you posted above @Mick West , they appear to be constructing a new construction service road down the hillside between the emergency spillway channel and the main spillway. You can see the beginning in the panorama on the extreme right. My...
  12. A

    Oroville Dam Drains in The Spillway Walls - How Do They Work?

    From the full resolution image It appears to be just stones.
  13. A

    Oroville Dam Spillway Failure

    I believe this is reference to this debris field shown caught against the FCS gate works FL_Oroville-2590_02_14_2017 (1) by AlmostaCE posted Feb 20, 2017 at 12:18 PM http://pixel-ca-dwr.photoshelter.com/galleries/C0000OxvlgXg3yfg/G00003YCcmDTx48Y/I0000NtLpqQZaW.4/FL-Oroville-2590-02-14-2017-jpg...
  14. A

    Oroville Dam Spillway Failure

    Any activities directly in front of or near the flood control structure would be ill advised with the gates open. While the floating boom provides some restraint of debris, its real purpose is to keep boaters and others out of the danger area where currents could pull them into the FCS.
  15. A

    Oroville Dam Spillway Failure

    The turbulence is a result of the piers between the gates, so 8 gates and 7 piers. The water passing through the throat of the gate is essentially laminar when the gate has head pressure.
  16. A

    Oroville Dam Spillway Failure

    I encourage folks to review this study regarding the flood control and spillway designs - its interesting to note how much the final constructed unit differs from the initial proposed designs, including some designs that initially included a larger outlet works for both normal and flood flow rates.
  17. A

    Oroville Dam Spillway Failure

    I believe you are correct - based on this photo from post Oroville Dam Spillway Failure']995[/URL] it appears that there are just 3 sets of drains between the gate house and the point the flood control channel becomes convex.
  18. A

    Oroville Dam Spillway Failure

    An excellent question I think. Overall, I don't see any way to replace/update the drain system in the upper section without removing the interior panels of the spillway. One could reasonably retain the 2 sidewalls and excavate outside of them to replace the longitudinal drain piping, but the...
  19. A

    Oroville Dam Spillway Failure

    In my opinion, a competent engineer or manager would not rely on the emergency spillway for reservoir control. This structure exists primarily for dam safety based on the designs we have seen documented previously. The lack of flow management and its high spill-over height (901') make it...
Back
Top