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.
Looks like a large bilge pump dumping out there! :)
Not a lot of action here, but this is the other camera setup that is located on the high side of the dam at the visitor’s center...
http://www.parks.ca.gov/live/lakeorovillesra
Juan Browne has a 5/25-26 update up on the blasting
https://www.youtube.com/watch?v=1ddkeBYpOEE
Regards
alfa6 :>}
Good shots of the blasting
Looks like they’re getting a little rain at Oroville. Just checking the progress on the Dam Cam video page.
They’re making a nice clean cutoff on the upper spillway. They’ve made it completely across now, and are digging out the debris. Drilling for blasting continues on the lower section, and the concrete plant to the right (towards the dam side of the spillway) is taking shape.
Only until the spillway was cranked up to 100,000 cfs did these massive slab blocks disappear. That is the time that the curious "Large Block" appeared at the end of the Main Spillway Chute - lodged against one of the flip bucket Chute Blocks.
That key picture from the worker makes him a hero for capturing critical evidence. This points to a larger problem of "void filling" on a big scale. DWR may be facing a difficult position as they are expecting 75% of the repair funding from FEMA. But, under FEMA's rules, this funding can only be from designated "disasters". If determined that the spillway crisis was from "negligent maintenance and/or repair activity (incompetent)", then CA & DWR risk losing the FEMA funding.
**distance to blocks from camera shot plus the relevant size of the reference dimensions of the upper main spillway seams.
Fig 8. from article - original pic taken by worker & posted on social media - was fired over this. Yet provides the only huge critical evidence no other pictures captured.
Fig 2. from article
Fig 3. from article
Fig 4. from article
Evidence of a 9+ foot thick Large Block of concrete at the bottom of the Main Spillway? Reveals dangerously large voids have formed in the past near the spillway"blowout" failure area? DSOD Inspectors told not to fix until damage occurs from "heavy flows"? Will this evidence of "Large Blocks" in "void fill" from possible under spillway slab erosion chasms derail DWR's narrative of any known failure indicators?
LOS ANGELES, CA (California Network) - In January 12, 2000, a California Division of Safety of Dams (DSOD) Inspector had noted areas identified as "drummy patches" on the main spillway [1]. These "patches" were acoustic echo tones that indicated voids large enough, from the dB level of acoustic response, to where the Inspector felt these were important enough to note these findings in the report. Typical "sounding" methods, in the early dam spillway inspection era, involved dragging heavy chains or hammering the top concrete to create acoustic stimulation. Alarmingly, this DSOD report stated that "No treatment is proposed until they [drummy patches] are damaged by heavy flow." Why wait for the spillway to be "damaged" from a "heavy flow" condition? This report was 17 years ago. Was DWR operating in this "wait until failure" methodology instead of proactively investigating & fixing potential catastrophic failures? This DSOD inspection report seems to infer a "reactive" failure response atmosphere. Is this key to the demise of the spillway?
The Blowout failure area has likely revealed a key piece of evidence of DWR performing "deep" filling of dangerous chasms under the main spillway in over a number of years in "void filling" repairs. The "evidence" is a large block of concrete that originated just above the "blowout" failure area in the spillway. Does this block reveal evidence of actions of serious repair attempts to a large scale underslab "void erosion" cavity to which the scale of its size would have been threatening a major failure of the spillway for years?
This sequence of photographs and images possibly reveals that DWR has been "filling" dangerous chasms of large voids instead of recognizing the serious nature of the imminent failure of the Main Spillway. This evidence, if found to be as it shows, would be severely damaging to DWR's position of not being aware of any failure risk to the Main Spillway.
==== end clip
Fig 9. & clip from article - "Fig 9. Original "Blow-out" failure of Main Spillway. No "Large Blocks" present. The upper failure seam in the spillway is where seepage has been observed originating in the spillway during non-operating conditions (dry - See Fig 14). This seam is also where muliple repairs have been performed over the years as evidenced in images of "cuts" in the slab concrete for nearly the full length of this seam. After additional flows of 30,000 cfs to 33,000 cfs on Feb 8, 2017, and then 45,000 cfs on Feb 9, 2017, is when rapid upslope spillway backcutting collapsing failure progressed. This "rapid upslope" spillway collapse was most likely accelerated by the unstable large "void fill" blocks that had little to no anchor bar integrity remaining. The spillway flow was stopped on Feb 10, 2017 for an inspection (See Fig 8.). That is when the stack of "large slab blocks" were observed washed to the far side of the erosion channel, abutting the still intact broken upper part of the lower spillway. This is the critical evidence that the "large slab blocks" originated just above this "original blow-out failure" location & in the same large highly erodible weathered rock seam (Fig 8.)."
Fig 14. & clip from article - "Fig 14. Water seeping up through at the original blowout failure area. Of significance is the lack of drain flow at an outlet. This location identifies that the drains above the seepage area are not functioning. The drains that feed this outlet are in the exact area of the large void fill slab block area."
You can assume there are many other photographs of this area taken at this time, other than this one. The investigators may have to subpoena them, however.
If a large grout pumping operation took place and created this large block of concrete, there is some record somewhere of the occurrence. And someone who was on the job who can testify under oath as to what happened.
That is exactly what is happening, but not by subpoena. People who worked on the repairs (witnesses), stating depths of 6 foot voids in the main spillway, and 4 foot voids in the Upper spillway, are coming forward to others to get the information out there. These workers are afraid of retribution as they have asked for their names not to be revealed. But they are well known by the person who they revealed this information to. Scott Cahill has revealed this publicly, but is keeping the individual's names protected (i.e. people coming to him in confidence on the repairs & the details).
This also raises the question of the Independent Forensic Review Team. What will be in their reports? If there is supporting evidence that this "void filling" occurred, then they will need to address this evidence in their reports. OR will there be great pressure from DWR? OR will there be information that somehow is not "volunteered" to the Forensic Team?
Keep in mind the physical evidence has been pulverized in the recent blasting.
Tonight there is a Flood Warning for the next two days for the Merced River coming out of Yosemite. Similarly they have had terrible drownings in the Keweah River in Sequoia National Park (3 as of yesterday) and six on the Kern River which drains to the south starting in upper Kings Canyon Park, going through the back country of Sequoia draining the slopes of Whitney as it heads due south. The flow on the Kern is described as 400 - 600% of normal for this time of year.
I spent some of last week in Kings Canyon, Sequoia and the Central Valley and the rivers coming out of the central Sierras are really running. It had spiked up to the mid 90s at the first of last week and the rivers were running as though a flooding rainstorm had just finished.
So far I’ve seen no spike in the Oroville Dam inflow.
Is spring melt in Oroville usually way behind the rivers in central California? Are they still expecting a huge inflow spike at Oroville?
My understanding is that they get a good steady inflow from melt up til the end of June and possibly July in a year like this.
As a construction worker, you might wonder or question the actions at the time. Yet the engineers responsible for the "standard of care" of their profession are required to know the implications of actions in their field of expertise.
Criminal Civil Court and Civil Law do not distinguish between "incompetency" and "corruption" (i.e. intentional deviancy). If engineers do not execute their duties to the level expected of their field of expertise, they are required to maintain a "Standard of Care" to their field of expertise. That is where Civil Law identifies the Liability in lawsuits from damages (life, property, et al). So they have no excuse.
That is why DWR may be facing a huge issue of "negligence" in performing to the "Standard of Care" in their profession. They may be exposed to lawsuits to reclaim damages incurred due to the spillway failure (i.e. farmers losing swaths of property from the abrupt on/off emergency mode of operating the spillway flows, business damages from evacuations, tourism damage, etc).
Perhaps now, with evidence mounting, the contractors who performed the repair work, may realize that they could be implicated in DWR's actions as contractors are also bound under the "Standard of Care" Civil Law definition. To protect themselves, they may need to come forward to share what they know. But to whom do they go to? This liability goes to the top in the State of California as DWR is an organization of the State of California.
One option may be to contact legislators Gallagher and Nielsen before all of this blows up into a public firestorm. It may be a firestorm, for CA may be holding the bag for $500 million in the repair costs as FEMA may be forced into a corner on withholding funding assistance as this potential issue is a "failure due to maintenance" verses an unforeseen "disaster" designation.
I could envision the state then trying to go after big fish contractors that may be caught up in this "Standard of Care" Legal Liability norm. It would be best for the contractors to get ahead of this curve.
The risk to the spillway right now is if the worst combination developed - a warm pineapple express. That would generate the greatest inflow spike.
AS for the norm, perhaps others have the typical history data (although this may not be exactly comparable to the existing snowpack).
Below is yesterday's 24-hour snow melt. Brighter Blue = 1.4" to 2" water equivalent from melt, green line is the Oroville Dam watershed boundary.
1"+ would normally have been a rather heavy melt day a copule of months ago with 70%+ snow cover across the whole watershed, but snow cover is only something like 3% today.
For comparison, here's what it looked like in March. This was for 72 hours, but you can see the snow cover was far greater.
So where did all of the snow cover go? Just 11 days ago the State was saying that they had a contingency plan to use the spillway one more time "If water from snowmelt in the Sierra Nevada fills the reservoir harder and faster than currently expected,"...(link below)
If you look at the snow water density map it shows the Oroville Catchment Basin near empty (white circled area).
Have you been following this? Why has the snow essentially disappeared in the Oroville Catchment Basin yet is dense (30 inches of water equivalent) exactly south on the southern edge of the Basin for a great distance?
Seems odd, in comparison with the news story. What's up?
Noaa map of water equivalent in snowpack. Oroville catchment basin (white circle) is almost nil while 30+ inch levels up and to the southern edge of the basin.???
DWR made that statement on the 20th, but started ripping things up in a serious way last week. A release after that point would have been problematic - erosion, debris in river, etc. Not catastrophic, but bad. Still, their actions last week tell me they were sufficiently confident of the low risk that they proceeded despite their earlier statement. If they ended up being wrong today, they would have reminded us that they did anticipate one more release. Expectations management, I guess.
Regional differences and weather patterns are enough to explain why the Oroville Reservoir basin melted off before the rest of the Sierra this year. They might get blasted next winter while the south remains dry. I've only been watching the weather there closely this year, but there is nothing like a consistent pattern across the entire Sierra. It's patchy and precipitation is often in narrow swaths. Tahoe and the eastern ranges generally get a lot more snow than the northern or southern ranges.
The 30+ inches of snow-water equivalent mostly applied to the Sierra mountain tops in the Oroville Watershed. Most of the catchment area had far less than that and it melted off weeks ago. They had a lot of snow this year, but nothing like the Tahoe snowpack below.
Those little blue areas on the snowmelt forecast (mountain tops/north faces) still do have several feet of snow and probably over 30" of snow water equivalent, but just in a few square km area. I'm sure there's still a risk of localized flooding from heavy melt runoff under those peaks, but nothing that translates to much of an effect overall on the Feather River forks.
I'm not familiar with the summer weather patterns there to speak to the possibility of torrential rains or another Pineapple Express in the Oroville watershed, but I don't think summer rain has been much of a problem there - at least not to the extent that it would force another release from the dam.
Hydro plant releases should be enough for this summer. I expect them to work well into December as well - the Nov. 1 'deadline' is another managing expectations thing. It would be extraordinary if they ever had to spill in November.
Bill Husa of the ChicoER took this great Google 360 image from the top of the gate house on June 1st (h/t Dan Reidel on Twitter).
If you pan over to the downstream side of the e-spillway weir, you can see a series of three little pads, each with a ground-level square white cover with some metal tubes protruding - the tallest of which looks like a gooseneck vent.
Screen caps from the image:
A closer view below with a nearby railroad tie included for scale. A common U.S. railroad tie is 8' (2.4m) long.
I don't have any specific information on what these are - piezos/flow gauges is just a guess. For all I know, they might be vent holes to DWR's secret underground lair. But that would be CEII, so you didn't hear that from me.
Plans are to add a pretty substantial RCC apron on the downstream side of the weir, so these would eventually be under several feet of concrete. They would have to build some kind of access to them or just remount higher on the surface of the new apron.
On old blueprints, the weir was shown to have a rectangular open box drain at grade that runs along the center of it's length, with T's every 40' or so emptying to the downstream side of the weir at the very bottom. They were not visible because the bottom edge of the monoliths were a few feet below the ground surface.
There appeared to be some kind of piping related to these drains washed out after the spill, but you couldn't make out much on how many there were or how they were accessed. The one blurry photograph that gave any clue suggested that at least one under-weir drain was piped to a small, square concrete basin, maybe 4'x4' and a foot deep, topped with a manhole cover. That manhole cover was never visible in any old photographs, so this may just have been something like a buried junction box for more than one drain.
I don't know if the new little access points are actually related to the under-weir drains or if they're piezometers to measure underground seepage independent of the drains. Either would make sense.
No wonder this is CEII - in either case noted above, these are obvious attack vectors for terrorists. How many times have we read about jihadis going after under-weir drains? Why, if I had a nickel for every time I read about these kind of tragic attacks...
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