About evacuation.....
There was a post here a couple weeks ago maybe, expressing concern about Susan Wolding and her cry to evacuate now being somewhat of a chicken little sort of problem, and if the dam holds up and nothing happens, in the long run it does more harm than good and makes her and by implication all the dam doomers lose credibility.
I meant to quote it and reply....not sure who posted it and don't remember what page.
I agree. By that I don't mean anybody is wrong to evacuate now, and I would want to get out permanently, but here is the problem:
If people are going to appeal to Scott and Lisa Cahill and their decades of dam remediation work, and their concerns about water porting under the hill and so forth, and make them an authority that the dam has problems and DWR is lying, then you can't turn around and dismiss what they have to say about non evacuation right now.
Back when the soil erosion started I wrote to Lisa Cahill and I posted it here, and Lisa has been active on Twitter. I specifically asked if signs of internal erosion meant people needed to evacuate now and she said no. A lot of people have called and emailed them and they are clear that dams can stay like this for years. (or days or hours). They have openly said that the dam may hold up this year and hopefully DWR will start intensive grouting and gate remediation this summer and maybe it will work.
Now personally a maybe isn't good enough for me. I would sell my house at a loss and get out and do anything to not be in the flood zone. But the dam could get gradually dismantled and not harm anybody, or there could be a 20 year drought ahead.
Dr. Robert Bea said the left abutment never sealed and that green spot is so worrisome that the dam could start breaching on a sunny summer day. Cahill described phreatic water levels and why the seepage should not be as high as that green spot. So its all very concerning. But, the dam could hold for another decade. We just don't know. DWR won't install the proper piezometers so even DWR doesn't know what is really going on.
The bottom line is that Susan Wolding is NOT somebody with 50 years of dam construction and remediation, and she has no business setting herself up as an authoritative voice that the dam is about to fail this year. When Cahills say it may hold up just fine, they should be respected.
With what looks like increasing earthquake activity, and a fault line in the lake itself, it is possible that people like Bea and Cahill could issue a public warning that evacuation should happen now, and if we began to see high levels of internal erosion I can picture Cahills issuing a warning to get out if you are below. But that isn't happening now.
I find Susan Wolding to be disrespectful of dam experts who are far more knowledgeable than she will ever be, saying the dam may hold up fine. She has no business insisting that it is 100% about to fail. Frankly I find her annoying, and while I as a cautious prepper would get out, it is just not right to be talking the way she talks.
Quoting: Prayandprepare000 Well Said! I agree with you 100 percent!
I almost totally agree but I'm a self acknowledged uneducated speculator so who but me really cares what I think anyhoo?
An official evac order will in reality mean gridlock.
Imagine watching live stream of up to a million people stranded bumper to bumper, children, wives, etc. screaming. Imagine that for a second.No one mistakes Susan Wolding for an official nor a dam specialist. She's just a woman with a heart trying to forewarn people. That's how she's perceived.
If that Dam blows and up to a million people do die at least Susan tried.
Don't get me wrong. I find this dam terrifying, mainly the gates. This link to the Tony Johnson section of the 124 page Bea report has been posted countless times here.
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link to www.catholic.org (secure)]
But, you can't appeal to Cahill as the great expert talking about porting water in the hill and so forth, and then turn around and say he should be ignored when Lisa says that there is no reason for an immediate evacuation.
I know they are working on another video, and since the last one they did, we saw that internal erosion (mud). It is entirely possible they will say the situation has gotten more dire. Or perhaps they will say DWR has been grouting and the mud has not increased.( it doesn't look as bad now). I just don't know. I think Susan and crew should urge people towards relocation without the "get out now the dam is going to break any second"sort of exhortations. But what do I know.
Scott Cahill already said that the new Emergency Spillway apron hillside will not hold and will cut back to the lake (as in 2017) despite the secant cut off wall they put in. That's as negative as you can get. Maybe if we had gotten up to 898 or 899 and DWR said they wanted to try out the new ES, he would have said it is time to evacuate. I trust them...that's my bottom line. I don't trust the people at Wolding's chat to be anywhere as rational and knowledgeable.
Yeah, a sudden evacuation would be gridlock. Getting out a couple days before it hit 900 would have been very wise.
Going back to the gates, and the link above.....
You know all the talk about vibrations on the new spillway? Marty DeAngelo's buddy at MIT who got into the DWR dam sensors in the new spillway and they showed vibration? Jack in VA with the twitter pics of the diamond pattern in the water flowing down?
This is from that link, and I wonder if the gates were the source of the vibration and that is why the spillway was vibrating:
Today's modern Radial Gate designs have revealed a new and powerful force dynamic that was not well known years ago. Up to 60 ton Radial Gates have experienced a powerful "vibration" oscillation condition from critical flow levels in the gate openings. A standing wave of high and low pressure oscillation develops on the lower skin plates of the radial gate that transfers a complex set of distortions and movements to the massive steel gate structure. Indeed, experts are now attributing this powerful resonant oscillation vibration condition as a key component to the catastrophic failure of the Folsom Radial Tainter Gate in 1995 [11]. The power of this multi-mode form of oscillation in the massive trunnion gate structure would be dominant in forces applied to the Oroville Spillway Radial Gate design to these weakly coupled side seal assemblies. The wave action of the resonance would easily focus high forces on the side seal assembly individual aligning J-Bolts (now upgraded to eyebolts). This could cause either a shift in the alignment from "slip" or from "rotation" in the bolt compression area of the eyebolts. The result could be a swift and dangerous form of a strong binding condition to the gate in a virtual "freeze" state.I wonder if the oscillation started and they panicked (with good reason) that they could have a Folsom gate #2 event and shut off the flow. Maybe the vibration was from this and not originating from the new spillway itself. Any thoughts from you engineering guys?
Anyway, I need to get some stuff done and get away from this dam LOL. Prayers for all.
