ToDaZeD CA *facepalm*

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  1. For some reason, I keep thinking of the Deep Water Horizon disaster. And, there’s even lots of water involved.

    Maybe it’s the “Hail Mary” of helicopters and bags of rock being mentioned. Sounds like desperation to me.

    But what do I know?

    Comment by Blake — February 13, 2017 @ 9:22 am

  2. Earth dams, when water has the opportunity to flow unimpeded anywhere on an unprotected outside slope, will eventually fail. More water, the faster the failure.

    I see what they’re trying to accomplish, but unless they stop the water flowing over the spillway for a time period long enough to place rock to fill the hole, the continued water pressure will wash much of it away, cause more failure, due to the weight on the super-saturated soil, and the erosion will continue toward the basin.

    If I had to guess, I’d say more rain will lead to the loss of the reservoir. Otherwise, ignoring wiser minds ten years ago has a cost.

    As you named your blog: “Knowledge is power”.

    Comment by Jess — February 13, 2017 @ 12:35 pm

  3. ^^ Seems azo I remember they used that technique to repair levee breaches in Nyawlins.

    Comment by DougM (side-eyed so-and-so) — February 13, 2017 @ 12:44 pm

  4. (1) Blake. I was thinking the same thing. And the oil leak was just one little pipe. Sure, it had enormous pressure, but still.

    As for the “bag of rocks” method, I hear from Wiley, my go to source on all things ACME, that ACME doesn’t have enough bags for this project.

    Comment by MikeG — February 13, 2017 @ 3:10 pm

  5. This might be a good time to remind folks that this is one good reason for avoiding gov’t deficits and debt. You have no way to handle emergencies quickly, and you probably have to beg for help from outsiders (who have conditions not necessarily in line with the taxpayers’ interests).

    Comment by DougM (side-eyed so-and-so) — February 13, 2017 @ 3:18 pm

  6. Yeah, so how come there are no pictures (that I can find) showing where they’re dumping those bags of rocks? No videos. No pictures. Why?

    Comment by Mike Soja — February 13, 2017 @ 7:55 pm

  7. ^how come there are no pictures
    Maybe because it’s more embarrassed Prog kabuki theater. At about 2 cubic yds. of rock per lift, it will take months of Blackhawk sorties with only five or six helos to bring a couple hundred thousand cubic yards to fill that hole.

    Comment by dick, not quite dead white guy — February 13, 2017 @ 9:17 pm

  8. ^^ Looks like they haven’t begun the helo ops yet:
    http://www.kcra.com/article/repair-work-on-lake-oroville-spillways-begins/8777148

    Comment by DougM (side-eyed so-and-so) — February 13, 2017 @ 9:42 pm

  9. They have begun some helo ops, though one report admitted a couple hour’s worth, while the general tone en mass was that it was all day. But dick is right in that helo drops are negligible (is that racist?) considering the scope of the erosion.

    I still haven’t seen any pictures or videos of a bag drop anywhere at the dam site.

    Comment by Mike Soja — February 14, 2017 @ 12:06 am

  10. ^ Yeah, I wanna see the bag-drop, too.
    When they did it in Nyawlins, it was really cool.

    I assume they’re gonna go back in with the quick-set concrete between the rocks. Dunno.

    I’d also like to see a cross-section of the footings and geology there. I know there’s some bed rock, but don’t know where or how the aux spillway foundation was designed.

    Nature: trying to kill you 24/7 (but it’s in no hurry)

    Comment by DougM (side-eyed so-and-so) — February 14, 2017 @ 11:45 am

  11. ^aux spillway?
    Make that faux spillway

    Comment by dick, not quite dead white guy — February 14, 2017 @ 12:19 pm

  12. Now when an idea comes along that’s obviously dumber than a bag of rocks, we’ll have a new mental image to accompany it — thanks, Cali!

    Comment by Auntie Media — February 14, 2017 @ 12:37 pm

  13. Couple of things:

    Earth and rubble dam wall are supposed to be built between ROCK abutments, to anchor the dam.

    They are also supposed to have a core of a special clay called “smectite” that acts as an “impermeable membrane” within the actual rubble wall.

    The water behind the wall can NEVER be allowed to rise above the level of this clay core or the water WILL penetrate the rubble structure and start to wash out the clay, with the obvious catastrophic results.

    Thus, the “engineers” should have been releasing water, via the floodgates, well before it got anywhere near that level.

    The “spillway is essentially an “emergency” overflow outlet, usually cut into the solid(ish) rock of the abutment, to automatically dump water well before it gets to the top of the dam core. Some dams even have the provision to deploy explosively-driven “blowout sections” in these rock spillways in the event the water is rising faster than the floodgates and the “Normal” spillway can release it. It is probably better to have a couple of days of “minor flooding” downstream, than a 100ft high wall of water going downstream at 60mph.

    Rubble-fill dam walls are actually a good idea in places prone to “seismic” activity, like you-know-where. The dam wall can flex a bit as the earth shuffles around, without simply cracking open.

    Any decision to let the water get to the point where the “emergency spillways” are in action, will have been “politically” motivated; “We MUST save all that water. Look how long the drought has been”.

    THEY won’t be the ones riding a giant wave down the valley when if “goes”.

    Comment by Bruce — February 14, 2017 @ 3:09 pm

  14. @MikeG – My thought when it came to helicopters and bags of rock to fill or stabilize the huge amount of erosion on the aux. spillway was that it would be the equivalent of trying to bail the Titanic with a teaspoon. I’ve seen helicopters in action carrying loads and they just cannot carry that much, relatively speaking, nor are they all that efficient when it comes to moving lots of material in a short amount of time.

    @ Mike Soja, I’ve seen video of helicopters moving the bags, but, strangely, there isn’t any video of where the bags are being dropped. It’s almost like the powers that be don’t it to be widely known that the amount of material being moved by helicopter isn’t really meaningful considering the scale of damage.

    Comment by Blake — February 14, 2017 @ 3:39 pm

  15. Bruce ^^
    Good briefing.
    When they started talking about the aux spillway, I was worried about erosion at the parking lot area on the left, mainly because it wasn’t clear if there was reinforcement there. Water seeping beneath the parking lot would end up being as bad as a breach in the aux spillway, so I dismissed that as a likely issue (too obvious).

    Blake ^
    Yeah, from what I’ve heard, the helos are assigned to areas the trucks can’t reach. The last vid I saw showed them filling over by the parking lot (see: para above)

    Looks like they have the water level way down, now.
    We’ll see what happens after the storms come through tomorrow and Thurs.

    I hope the CA voters remember who spend their billions on glamorous high-speed rail and PC immigrants, rather than on the boring, mandatory, routine gov’t stuff… like dams.

    Comment by DougM (side-eyed so-and-so) — February 14, 2017 @ 4:13 pm

  16. @DougM, the other thing that bothers me is that all this work is being done on the aux. spillway, yet, curiously, there is little mention of the main spillway, which looks to me like it should be stabilized also.

    I get that that aux. spillway needs to be repaired because of the danger to the damn, but I find it hard to believe the continuous undercutting of the main spillway (part of a riverbed in Minneapolis collapsed due to undercutting. The river wore down the softer material underneath until the harder rock on top could no longer support the shelf) isn’t also extremely serious.

    Of course, it’s also possible the water flow down the main spillway isn’t undercutting the the section of the spillway that is intact. But it would be nice if news agencies would give us a broader picture of what’s going on. /rant

    Comment by Blake — February 14, 2017 @ 4:40 pm

  17. I’ve seen video of the bags of rock, and some bags of sand?, are being used around the parking lot. (CHP helicopter video.) They know water erosion undercutting the far side of the emergency spillway will lead to its failure just as easily as closer locations.

    Problem is, no matter where they add the bags, (or even mortar in a fresh rock layer), it will be undercut on the downstream side unless it is built on bedrock. (Even then the bedrock in this area seems to erode quite steadily.) This calls for a steep overhanging drop-off, which is currently apparent on the damaged spillway, which has prevented its further uphill erosion. I’m not sure there is a way to create this type of overhang, or waterfall effect, on the hillside downstream of the emergency spillway.

    Comment by FishOrMan — February 14, 2017 @ 9:54 pm

  18. Also, I’ve heard numbers from the last storm was inputting close to 200,000 cubic feet per second into the reservoir. With the current output on the damaged spillway at 100,000 cubic feet per second for the last 2 days, it would take 2 days at 200,000 cubic feet per second to be right back to the top of the emergency spillway. It appears it will be closer to 4 days of release at 100,000 so it will take 4 days at those higher input levels to bring the reservoir back to full where they might have to test the emergency spillway again.

    They can, of course, still open the spillway gates even more. I believe it maxes out around 160,000 cubic feet per second, (a number still under some of the input levels they have recently seen). This could increase the erosion of the cement spillway, (and no lawyer wants to have to defend the action that caused that), so I believe they will wait until they are forced to do it when the emergency spillway again shows erosion happening around its footings. The only reason the erosion around the footing stopped on Sunday with the 100,000 cubic feet per second spillway release was because the input levels of the reservoir had dropped dramatically and this release was able to lower the reservoir. If they had had this trouble while the rain event was still ongoing, their efforts wouldn’t have lowered the lake and the undermining of the footings would have continued.

    Comment by FishOrMan — February 14, 2017 @ 9:59 pm

  19. Personally, I think they need someone with a pair of balls to make the decision to increase the spillway to its highest levels right now. There really is no chance their quick fixes under the emergency spillway are going to stabilize that hillside to prevent erosion on the downhill side, leaving whatever they have done undermined and collapsing. The cement spillway, although damaged, still has a much better chance of surviving that extra 60,000+ cubic feet per second than the hillside, which caused 200,000 people to be evacuated while it was only in the 8,000 – 12,000 cubic feet per second range.

    Comment by FishOrMan — February 14, 2017 @ 10:02 pm

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