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.
If one is standing with the ES & MS to the left, then this seepage is toward the right, toward the power station and on the side of the dam facing toward the river?
Bad bad news....
...and there is no way to defuse the bomb...
5 p.m. California time ... flow is at 10,000 CFS.
They should provide large zoom pics of the three "downslope shift" optical targets to the public.
I looked up “smarmy bureaucrat” in the dictionary,
and they had a picture of Bill Croyle there.
= = Key insightful quotes to article: (emphasis mine)
Engineers expect to have this summer’s repair plans largely in place by early next week for the concrete spillway, said Bill Croyle, the acting director of the state Department of Water Resources.
“If I have anything to say about it, we’ll have a spillway to use by Nov. 1,” Croyle said, referring to the expected start of the next rainy season. “Whether that’s a permanent or temporary structure, it hasn’t yet been decided.”
Good. Grief.
A LOT of heads should roll on this. Probably including the Governor.
Excellent catch on your part. I hope you have some official input into this thing before it’s all over. An informed voice of sanity and common sense is sorely needed.
It is midnight in California
Lake level = 836.6
Flow has been about 11,000 CFS for the last 8 hours.
(I thought they said with a flow that low would it would
tend to erode the face of what is left of the spillway?)
The vegetation covers a fairly large area on the opposite side of the dam from where the Dam Inspection Report photo was taken (right gallery access parking area).
Zoom in on the area above the powerhouse.
They’ve shut down the spillway as of mid-day yesterday. The 11000 or so is flowing through e Hyatt plant inside the dam.
New images reveal the extent to what the Inspectors noted as recommended actions to be taken (1) Investigate the cause of this long term water weepage in the mid-slope region of the backside of the earthen dam. (2) Take action base upon findings to protect & ensure the integrity of the stability of the slope (long term stability)."
The images show that many erosion channels have developed on the surface of the dam where these channels are originating from the water "wet area" or "weepage". Green vegetation reveals the presence of water supply on the dam embankment.
A larger image reveals the reservoir water level to be higher than this water flow seepage area. Thus there is a down slope pressure "head" component to this situation.
The last sign you want to see on an earthen dam is water penetration. This is how the tragic Idaho Teton dam failure started - a hillside "leak". So far, the 2014, 2015 recommendations of "action" by the Oroville Dam Inspection Reports have seemed to be a second thought in the 2016 Inspection report (i.e. hillside is not green anymore due to the drought - as would be the case if the water levels had dropped in the drought condition). The evidence is strong that there is a leakage penetration path in the dam itself. With the prolonged high reservoir water elevations of 2017, this potential "leakage penetration path" could continue to be affected. Masking the detection of any new changes is the greening of the whole backside of the dam from the wet 2017 season.
Related post:
Water penetration "sign" with green vegetation and erosion channels down the mid-slope of the backside of Oroville dam. Dam Inspectors noted this in 2014 & 2015 reports stated this should be investigated & acted upon based on findings.
Waterflow area (weepage or wet zone @ 660ft mid-slope) shown at an elevation below the reservoir water level (800+ ft).
Now I understand your point. The upper throat has the appearance of some Venturi features.
I am curious how local and distant communities draw water from the lake. Is it only from the Feather itself?
As I recall the water for distribution is collected at the Thermolito Forebay.
Wow. The other shoe hitting the floor so to speak.
Seepage over time is one reason I intuitively question earthen dams - at least very large earthen dams like this one.
What’s the fix Doc?
The first step must be to investigate it. Weepage does occur at dams**, but what is unusual about this situation is that it is along a "seam area". If there is water leakage along a thin crack like defect (in the compacted clay water wall barrier), then the hydraulic erosion effects are spread. If the leakage source is a focused area in the compacted clay, then the hydraulic erosive potential notably escalates the risk factor.
The immediate prudent action to the existence of an unknown "risk factor" - in a proven long term existence of a "weepage" area with downhill erosion marks - is to lower the reservoir level below the elevation of the leak. This means, that to eliminate an unknown risk, the water level would be lowered to 660ft or below.
Then investigative procedures would be enacted to identify the saturation profile within the dam (probes). With this data, remedial repairs would be performed accordingly in the breaching area(s). (some dam remedial repair on notable leaks required excavation and replacement of the core layer defect using large volumes of mixed clay including Bentonite).
**It is normal to have some "weepage" in dams. However, if the source is not accurately investigated, this creates an unknown regarding a risk factor. What is surprising is that this seems that it was not investigated.
Unbelievable. Just... wow.
Great analysis, thank you.
The incompetence on display is so bad it’s hard to even know where to start.
I hope at least some of the people who live in the town of Oroville are reading this thread. Since FR is conservative, this thread would automatically be discredited by the media and most people in California. So actually getting the information out to people in general would require some other channel of communication even if a few locals learn it here.
At some point perhaps the local paper, the Oroville Mercury Register, could be contacted with key info from this thread?
It might not take many locals to raise enough of an alarm to wake up the people at the paper. The people of Oroville are the ones with the most to lose, and their voice WOULD be heard if they became alarmed.
My question would be, is it seeping through the dam or is it seeping in from the side via surface soil material. Your testing would certainly bear that out. Would there be an easy test to determine an alternative path?
Was the vegetation present during extreme drought when the only source of water at that level might have been through the dam? Could the moisture be coming UP from deeper down? Lots of questions that might help determine the source of the water presence.
Apparently, they've know about this for at least three years and apparently have done nothing about it. During the prolonged drought one would think the water level could easily have been taken down to 660ft to allow corrective action.
This is starting to look like a great example of government's inherent disinterest in human life by implementing a huge, potentially dangerous project and following up with little-to-no accountability and responsibility to ensure the potential danger does not become an imminent threat which this whole Oroville Dam monstrosity is starting to look like.
It is interesting that common law assigns "strict liability" to certain "abnormally dangerous" undertakings. Damming up water is one such "abnormally dangerous" undertaking. "Strict liability" means that negligence is not required for liability if damage occurs from the undertaking. One is liable simply by taking on such an abnormally dangerous activity regardless of how careful he is.
But this is government, so who is strictly liable? The government? If so, how does government pay for the damages? With their money? But government doesn't have any money. It only has OUR money. So government pays for damages with the money of those it damaged. So effectively, government isn't liable for anything.
One way of looking at this government conundrum is that because building the dam was an activity by a representative government, it means that at least theoretically that the dam was actually authorized by the collective people who wittingly or unwittingly have taken on that liability themselves.
Anyway, in this case, it looks like the people need to kick some butt to get corrective action to move this thing away from what looks like an imminent threat on a massive scale.
video of the shutoff yesterday
https://www.youtube.com/watch?v=ixTg5Tgzeus
dark discolored area coming from the rock bolts
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