Emergency: California’s Oroville Dam Spillway Near Failure, Evacuations Ordered

Breitbart ^ | Feb 12, 2017 | Joel B. Pollak1

[abb]

They sure ain’t skimping on the rebar this time around...

[EarthResearcher333]

No kidding (rebar).

The new spillway design/construction, when compared to the old design, is hard to even describe in the major improvements in structural integrity.

The only questionable "weak" area, compared the the density of the sidewall slab anchor bolts (30) is the transverse force transfer of the density of these anchor bolts to the vertical junction of the Sidewall Slab. Perhaps Finite Element Analysis simulations were performed that answer the complex transfer of forces of the concrete/rebar design at this junction. If you calculate the total 30 anchor bolt "hold down" tensile strength, minus the bolts for the horizontal spillway flow, the bolts exceed the transverse forces by the straight concrete and rebar alone intersection that is assumed to be for sidewall forces (including max flows during an earthquake).

(This discussion was in prior postings). It would have been helpful if DWR would have released this information so that these structural questions may be open for analysis (to immediately catch any "oversights").

However, it is too late now to change the design.

[KC Burke]

I will agree that most curing compounds are temporary and meant to wear away so that later treatments can be added for sealing or hardening if required by the final use. White Pigmented compound, waxey or latex type material, is used to make sure the color will show it has been applied in a uniform manner and then in a number of months it will show where it as worn away by weather and exposure.

I am not familiar with any epoxy used for curing. Concrete curing works on a curve. 28 day strength is used as a testing milestone to compare the concrete being placed to the mix design with history that was approved. Concrete often gains strength for one of more years but it is generally accepted that the compressive strength gain is at 98 to 99% at 28 days so that is used as a test milestone and it doesn’t matter what the final strength is for most uses.

In wall placement, the form itself forms a great barrier to moisture loss and hence in a cure during the first day. Depending on the cycle needed and the engineers design requirements, strength has developed sufficiently to remove wall forms in 24 to 72 hours depending upon the load imposed by the removal of bracing. Backfill or other loads are generally further delayed.

[EarthResearcher333]

"Road constructors refer to it as “white pig.”

Pig as in Pigment I assume. Would be curious/odd if it were a swine reference (likely a story behind it if so).

btw - I believe the white epoxy was chosen due to the immediate adhesion characteristics required for the vertical surface of the concrete, its height, and the necessity of expedient construction. Other horizontal based coatings may not be optimal for all of the necessary vertical uniformity considerations/factors - especially the heat & the effects of immediate adhesion integrity.

There is likely going to be another phase to the finishing of the sidewall concrete surface. The holes left by the wood form bolts require "filling". I suspect they will have another "step" regarding either the removal of the coating of epoxy before the final finish or ?. Shouldn't have to wait long to find out.

[mad_as_he$$]

Hey ER, with respect to the green spot(s). Seems to me that a botanist may be able to contribute to the conversation. There are plant(s), native to the area, that have a life cycle and when they are done with the cycle they turn brown with water present or no water present. Have you seen any reference to DWR having a plant specialist inspect the growth in these areas and catalogue the vegetation?

[abb]

Yes, the “pig” is the pigment in the solution. IIRC, the coating had to be continually agitated to keep the pigment properly mixed. The white served to reflect sunlight and helped keep the temps lower.

My guess is they’ll leave the epoxy coating. It shouldn’t harm the concrete, and it will eventually weather/erode away, especially after water flows over it.

[EarthResearcher333]

One of the years past DSOD reports did identify a classification to some of the observed vegetation (besides the grass variety). I didn't see any more reports on this classification in any further DSOD reports. It is possible that some internal notes were being kept or studied.

You are correct about the photosynthesis process reaching a "stress" crisis leading to a reaction in the type of plant to dormancy or death.

However, the most important factor to this "plant" green to brown discussion has been completely ignored by DWR in their latest report. This is a huge item. The item is the evaporation rate induced by the thermal absorption of the embankment face. Temperatures can reach 125F in the typical Oroville summer average temperatures on this embankment face. Given the large square footage of this elevated surface temperature, the rate of any water source would experience a significant evaporation rate.

This evaporative rate was calculated to be in the hundreds of gallons per minute (conservative calc over the observed greenage area square footage).

If you use a surface temperature that is 105F from a "shading" from grasses, the gallons per minute evaporative rate is still very large.

Looking carefully at what this means reveals that deeper water must be present to act as a "heat sink" to facilitate the presence of this embankment surface water - even in the midst of the significant evaporative rate.

IF DWR had included all of these factors in their recent Green Area report, they would have uncovered a bigger problem that their report couldn't answer...the sheer volume of water necessary to facilitate such conditions, even when the grasses "brown" from photosynthesis shutdown/dormancy "stresses".

In 2015, in the midst of a drought and brown grasses, DSOD inspectors found water present. So for this water to be present, with such heat and high evaporative rates, during an on-going drought, the only mechanism that can result in this condition is a "source" that is not rainfall, and a "source" that has a "flow", and a "source" with a depth of flow to "cool" the surface enough so that the evaporative escape volume still will not overcome the balance such that "water" can still be present.

That is exactly one of the reasons why Professor Robert Bea's recent analysis and commentary to the media in his statement that DWR only created a "superficial report" & that DWR needs to fully investigate this problem. It is too important to try to "make up a rainfall only" report when there are significant issues NOT even considered - thus they are risking the UNKNOWNS that could lead to a dam crisis (or worse, an escalation to a failure).

[The Westerner]

I've been thinking all week about the failure by DWR to acknowledge the green patch. It may have been in the redacted from public eyes section. I hope so. Because on 9/11 this week, we were counting up the deaths that the Arabs took while crashing American jetliners into living people and buildings; plus tallying the loss of life from Hurricane Irma.

This is hard to put in writing but it must be said:

The number of Americans who will die after a catastrophic failure of the tallest dam in the USA will be exponentially higher.

This is so serious that I've come to the conclusion that somehow, someone, must ring the alarm. The Governor of California is responsible for the longterm evasion of Oroville Dam's current and future problem now of the Emergency Spillway and next if and when the dam is breached. And from trying to stretch my few brain cells to understand the physics you explained above last week, there isn't any doubt in my mind that “Houston, we have a problem.”

To all who are reading this historical thread, what can we do to make Californians aware en masse that they need to demand an honest, non-redacted investigation of the green patch growing on the side of one of the most important sources of water for North, Central and Southern counties?

[EarthResearcher333]

BTW - There are good people working hard "inside the system" to get proper analyses done regarding the threat of the leaking within the dam.

Re: Redaction: DWR has NOT released ANY of the cited references in their Green area report. So it is not an issue of redaction, it is an issue of numerous documents that are 100% NOT available for independent expert confirmation of their analyses.

= =

Opinion/Observation: Until major changes occur within DWR, it will be business as usual. Proof: Look at the recent articles revealing the indecision and disarray exhibited by DWR - to where the sheriff accidentally discovered the danger and then drove DWR to accept the decision to evacuate 188,000+ residents, who were at an immediate risk of a 30 foot wall of water racing down the mountain, potentially within an hour.

This history reveals that the public will likely not have any substantive warning to a suddenly developing problem if it were related to an escalation of leakage (to the level of a threat to the dam). What likely will occur is that individual conscientious "sources" will inform the public via back channels. Social media will then take over. The citizens may only get a warning early enough through such "channels or sources". The information would quickly be boosted by other people observing "activity" at the face of the dam (inspectors, potential equipment, etc).

During any "social media" escalation to new information, DWR will have to respond with "statements", yet the issue becomes that to which DWR cannot answer the degree of the danger as they have no idea to the internal state of the dam (broken instruments & relying on peripheral "indicators" only via seepage).

So essentially, the public is left in a state of - "who do you trust?" - the public may take action to get out of harms way to be on the safe side. This may be turn out to be what saves more lives.

I believe that DWR did a great disservice to the public in issuing a "Public Relations" Green Area report rather than a real comprehensive "face the full facts" engineering analysis and true risk assessment. By DWR choosing "A Public Relations" report, they are instilling complacency in the public to the danger that may be lurking. This instilled complacency could make the difference between the public making their own decision to get out of harms way when the only source of real information on an escalation is from "social media" breaking information.

[EarthResearcher333]

Prep work for RCC - a ShotCrete inner sidewall l- Drilling, Hammering, + Adhesive --> Anchor Bars into RCC

Workers preparing reinforcement steel mesh and anchor bars to emplace a layer of a structural Shotcrete inner section for the temporary* RCC spillway sidewalls. Holes are first drilled into the RCC, then the Anchor bars are hammered into the RCC. Other images reveal a blue color type of adhesive used around the anchor bars placed using a caulking gun. It is likely the adhesive is placed in the drilled hole before hammering the "L" shaped anchor bars into the RCC (inferred by a bulging circular extrusion of the adhesive at the protruding bar opening when the anchor bar is fully seated to depth).

An inner layer and outer layer of steel mesh provide reinforcement to the next step of placement of the structural concrete. DWR notes that this step will be done as ShotCrete. This process eliminates the need for a wooden form, but adds a complexity of keeping the "flow line surface" of the inner wall to be constructed using guide "jigs" (or lasers?) and skilled hand surfacing work. Future images will reveal what their planned process will be to accomplish this important wall surface alignment. Any ripples in the wall could induce turbulence or even undesirable damaging cavitation effects in high speed flows.

The choice of Shotcrete gives an advantage of speed of construction to meet the tight schedule demands.

*All of this wall is temporary for the 2017/2018 rainy season. The sidewall will all be demolished and replaced with the final structural design as observed in the upper and lower spillway sections in the 2018 construction phase.

Scaffolding along the thick RCC sidewall - workers doing final prep work before a Shotcrete wall is applied to the inner section of the thick RCC temporary sidewalls.

Close up view of the drilling and emplacement of Anchor bars. Outer wire mesh layer is wire tied to the anchor bars. Adhesive (epoxy?) observed as part of the anchor bar emplacement (including hammering the bars into the holes). Inner wire mesh already partially imbedded in the RCC.

[The Westerner]

Your answer to my post convinced me that your piezometers(sp?) aren't being replaced because the managers don't want to know the true answers.

In a seismic region, it requires hyper-vigilance to monitor things you've mentioned like settling in the wall of the dam. All of your colleagues here know more of the types of things that can cause this tallest dam in America to suddenly breach.

I am reminded of the scene in Atlas Shrugged where the villain owner of a railroad is introduced. His first words are, “Don't bother me, don't bother me, don't bother me”! In the first half of the 20th century, great men, responsible men, built dams across the Western states. They foresaw the need of Progress which required water for great farms, ranches, and cities.

The second half of the 20th Century, the era of John Dewey's Progressive education begun in the 1920’s, brought us the stagnation of progress, character building and independent minds. The result was the politicians like Moonbeam and his big bureaucracy of passing the buck mediocrities.

It is heartening that men still exist who have brains, dedication, wisdom and are willing to fight, like Prof. Bea at Berkeley and my longtime hero, Dr. Bill Wattenburg of Berkeley and Chico. Thank you for all you fellows are doing!

[Ray76]

Assessment of the Vegetation Area
on the Face of the Oroville Dam
August 30, 2017

http://www.water.ca.gov/docs/Assessment_of_the_Oroville_Vegetation_Area.pdf

Apologies if this has been previously posted

[EarthResearcher333]

DWR finds Spring Under Spillway - In Blowout failure Clay Seam Streak - In Upslope section of large deep Clay Seam Original Spillway built upon

How ironic. DWR finds a Spring Under the Spillway after Kiewit evacuated the clay to bedrock. This "spring" is shown leaking water down the rock and forming a "pool" at the original Blowout Failure location (See Fig 2).

At the same time of DWR finding and now "studying" this Natural Spring underneath the Spillway, DWR publishes a report on the Green Spot on the Dam that is devoid of their original analyses presented as "a Natural Spring" and "Natural Springs" by DWR engineer(s) to the public.

DWR is "all in" on the new position of "rainfall only". So why does DWR ignore the extensive 2014 Dam Failure analysis FERC Part 12D report given by DWR to FERC stating their are "Natural Springs" in the Left Abutment? That in certain conditions, these "Natural Springs" represent a Potential Failure Mode (PFM) to the Dam? Yet in their new Green Spot report all of this is missing? Is DWR putting out a report that is mainly to deal with "Public Relations" rather than a full in-depth analysis? (such as the Part 12D 2014 original analysis)?

There are numerous discrepancies in the new Green Spot report that DWR is preventing outside independent experts from analyzing (references and sources).

The "discovery" of this Spring underneath the Spillway seems very ironic considering DWR's "narratives" re: Green Spot Report.

This all leads back to the question to the demonstrated "narrative" history by DWR: "Engineering Incompetence or Calculated Engineering Deception? - On the Record Examples from DWR officials in Press Releases, Town Halls, to the Press, and Testimony in State Legislative Hearings 2017". See post link. DWR Organizational Ethics? - Engineering Incompetence or Calculated Engineering Deception?

*April 27, 2017, town hall meeting: DWR engineer states to the public that the Green Wet Area caused by "a Natural Spring". DWR then "backs off" when it's pointed out that water cannot flow uphill. At the next town hall meeting in May, DWR then says Green Area is from "rain" (doesn't even mention a "Natural Spring" or explain why the DWR engineer was incorrect (seemingly) in his analysis/statement at the April 27 meeting).

Fig 1. DWR finds "Natural Spring" under spillway after excavating "clay". Spring & its end flow is in large clay seam area of the "plunge pool" & flows to the Blowout Failure area. Green Spot Report dropped "Natural Springs" from original DWR statements/analysis in town hall meetings (Irony). DWR using a "sump pump" to keep the spring water pumped out and away.

Fig 2. Origin of "Natural Spring" and its flow within and to the original large/deep clay seam of the blowout failure area. Spring Elevation is below reservoir level over 100ft at date of photo. Likely an aquifer source as evidenced by other prior seepage imagery from the original spillway construction (postcard image)

[Repeal The 17th]

OK, correct me if I am wrong, but...
Isn’t this the same area, during the original construction,
where the contractor wanted to excavate down to ‘good rock’,
but the state guy thought they were just looking to get more money,
and told them to just go ahead and build it on the ‘bad rock’?

[EarthResearcher333]

Poor foundation material removal - Clay from under Original Upper Spillway revealed - Rest of Upper Spillway needs 3,000 rock anchor bolts to secure slabs

Photos reveal the original foundation materials that the old spillway was built upon. All of the unacceptable foundation material has been excavated to "sound" rock (bedrock). The depth of the excavation reveals how much "unacceptable" foundation material was underneath the Spillway (Fig 2).

Deep Clay is revealed in the deepest of rock crevices (Fig 1) that are being hand excavated. Dump box reveals the clay and its consistency as dumped from a bucket. The upper right corner of the dump box shows how the clay responds to moisture (pasty). The existence of this deep layer of clay reveals that the spillway operation did not wash as deep to this level to remove or erode. But it does reveal the substructure stability risk issue(s) (clay seams and saturation potential) that the upper "unacceptable" foundation material was built upon.

This is very likely why DWR/BOC has emplaced ~3,000 rock anchor bolts in the remaining section of the upper main spillway. They likely are concerned about the "unacceptable" foundation material and the "clay layers & seams", revealed in these photos, of the Upper Spillway that is being rebuilt securely.

Fig 1. Deep seams of clay being hand excavated by workers (in Upper Main Spillway section). Reveals the existence of clay even in deep foundation areas of the original spillway. Poses numerous issues with piping potential, slump of structural support, and anchorage integrity problems if not removed to sound bedrock.

Fig 2. Clay qualities revealed in dump box. Pasty wet clay in corner of box when clay is moisturized. Depth of excavation reveals how much "unacceptable" foundation material existed under the original Upper Main Spillway. No sign of any "backfill" concrete from original construction - even from residual attachment to clean bedrock.

[EarthResearcher333]

Your statement is correct.

DWR's Final Construction Report Spec 65-09 documents these specific details of the DWR field engineer overriding the construction contractor and telling the contractor to only excavate "to grade" level per the drawings. This means that any section of the spillway that had clay seams would "remain" (See FR post link below).

The contractor was following the original DWR designer's spec's to dig to "sound rock", and if the "sound rock" was below "grade" then the contractor was to place "backfill concrete" to restore the slope to the original base "grade" that the slabs would be built upon.

Why did the DWR field engineer make this critical "change"?

Again, the DWR Final Construction Report Spec 65-09 reveals that someone, at DWR, did anchor bar testing that included clay, as this was "the worst foundation available". Since this test yielded a chosen 30,000 tensile psi pull strength (likely when the clay was hard and dry), the construction orders were changed away from excavating to fresh bedrock.

The interim Independent Forensic Team (IFT) report noted this general issue, but worded it in a subtle & gentle way such that you had to discern the severity of how bad this issue destabilized the spillway from high pressurized cracked slab water flows under the spillway - and its impact to the poor clay foundation areas - to its ultimate destruction.

See related & more details at link: (Note: the IFT's interim report recently set the record straight regarding DWR's insistence that the original spillway was built upon "good competent rock". Ouch): DWR tells another Whopper? Reporter corners DWR on FERC PFMA on Spillway - DWR says full spillway was built on "good competent rock"

[Repeal The 17th]

OK, thanks.
Is this also the same area where we now have to deal with the natural spring?

[EarthResearcher333]

The "pooling" area in Fig 2 is closer to the blowout failure area. The origin point of the natural spring is upslope closer to where the electrical towers were (and the uphill eroding spillway).

Since all of the poor foundation material (clay & highly weathered rock) is removed to clean bedrock, any seepage from sources under the final design will find its way to the drain rock channels without concerns of subsurface erosion. They will likely do some sealing of the rock at the spring before placing leveling concrete on top of it (final construction - RCC will be temporary construction there in 2017/2018 rainy season).

Even without the existence of a spring, there is water that will percolate to the surface of the bedrock to the foundation & bedrock boundary. The tremendous load pressure of spillway water flows will induce a significant "pressure force" on the bedrock. This too influences subsurface water percolation through micro cracks in the bedrock. The drains will collect this seepage from below as the graveled "channels" go directly to the bedrock.

Note: There are no formal drain channels in temporary RCC section. Thus any subsurface seepage will migrate however it can within the bedrock cracks and if any porosity within the RCC bottom seam.

Operating procedures require a gradual increase and decrease in the spillway flows to allow a gradual adjustment of the bedrock strain (change of shape) in base stresses (load force) from these tremendous load fluctuations. That is why it takes time to ramp up and ramp down (normal operations) of the spillway flows. Only in an emergency will this procedure be deviated from. These forces will influence subsurface seepage if water is present.

[The Westerner]

ER, the photos are beautiful. That red clay being excavated to expose the “good” bedrock means the new spillway is being built correctly, no?

If I were a 4-5th grade school teacher, I'd use this thread with its stunning photographs to teach the lesson on “Conservation”, not 1960’s version that our public schools taught, but 2017 version! There are lessons in cause and effect, dam construction, moral vs. practical, work ethic, taking responsibility vs. passing the buck, the longterm consequence of evasion or omitting unpleasant details, etc. If anyone can think of more lessons for 5th classes, let me know.

[EarthResearcher333]

"That red clay being excavated to expose the “good” bedrock means the new spillway is being built correctly, no?"

Yes, Kiewit & their subcontractors are constructing the spillway to ideal standards. Excellent work in foundation preparation.