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

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

[janetjanet998]

The California Department of Water Resources issued a sudden evacuation order shortly before 5 p.m. Sunday for residents near the Oroville Dam in northern California, warning that the dam’s emergency spillway would fail in the next 60 minutes.

The Oroville Dam is the highest in the nation.

[Jim W N]

So it seems like at some point between the “pre-failure” and the “critical acceleration”, you on the “receiving end” decide to take action/bail. Apparently that point is nebulous and obscure.

I guess how you respond on the receiving end depends on the seriousness of the possible result. The seriousness of the catastrophe of the Oroville dam failing would make me wonder how long those poor folks in Oroville would/should remain in harm’s way since apparently the dam itself is in “pre-failure” mode.

[meyer]

Yes, Juan is a good resource. Speaks in layman’s terms and doesn’t induce panic. We have a couple of posters here that are very familiar with the subject material though, at a more engineering/scientific level.

I’ve been watching Juan’s videos, and even sent a small donation.

[Repeal The 17th]

We are all fans Juan Browne here.
All of his videos are linked in this thread.

...but I just don’t ‘get’ the ‘white lily’ (blanco lirio) thing...

[EarthResearcher333]

Oroville 1964 - Sharp Slope of Rock - Left Abutment - Green Area - Trench to Anchor Core in Hillside Rock

An insightful early construction image reveals a wide trench cut in bedrock on the abutment hillside. This trench is designed to anchor the Zone 2 - Core (clay-clayey Zone 1) - Zone 2 sandwich design into the hillside bedrock. The orange colored core material is compacted upon the 300,000 cubic yard concrete "coreblock". The darker Zone 2 "transition zones" are observed adjacent to the center Zone 1 Core. The original Coffer Dam is observed to the left of the core region and meets at the parapet of the subsurface concrete "coreblock". Due to the construction sequencing, the downstream Zone 3 "Shell layer" was being emplaced in the center. To keep the access roads open on the hillsides, for construction of the hillside bedrock trenching formation (blasting, excavation, grout sealing), the downstream Zone 3 fill was built up in a form of a "hump shape".

This image also reveals the consistent sharp steepness of the "future" left abutment of the downstream Zone 3 fill. This sharp elevation drop goes to the "trench" boundary. Above the consistent "sharp elevation drop" is a "shallow slope", or semi-flat bench just above 600ft elevation. Thus, the future "Leaking" & "Green" wet area water flow is consistent with this "transition from a shallow bench area to a sharp hillside slope". This forms a classic differential settlement abutment zone potential. Especially since the shallow-to-sharp slope transition continues back directly to the junction of the "trench" boundary (to the Core region).

p.s. "Greetings to Boilermaker @ metabunk"

Early construction image - wide trench cut in bedrock to anchor core - Green Wet area at transition zone of shallow-steep slope that reaches back to the core zone. Classic "differential settlement" potential.

[meyer]

I’ll have to study that image for a bit to get my bearings straight. Great information as usual. Doing the preventive investigation that the DWR won’t do.

[meyer]

New images have been added to their page...

https://pixel-ca-dwr.photoshelter.com/galleries/C0000OxvlgXg3yfg/G00003YCcmDTx48Y/I0000kX.qAevmpGk/MB-Oroville-1428-05-01-2017-jpg

It’s interesting to note that the water appears to be much clearer at reduced flow than it has been the previous 2 times that they shut down the spillway.

[Jim W N]

I, too, have enjoyed Juan Browne’s down-to-earth videos and presentations. However, he seems to come across to me sometimes as a bit of an apologist for the DWR or, at least earlier, a bit of a denier of the seriousness of the dam’s problems.

[meyer]

And speaking of Juan Browne, his latest from May 1...

https://www.youtube.com/watch?v=9NaxuXzVht0&feature=share

[EarthResearcher333]

Hi meyer, This illustrated blueprint should help understand the prior "early construction" and hillside trench excavation picture. The original picture upthread is a side view looking at the "length" of the crest of the "future" dam from the NorthWest side. Turns out this aligns with the same view in the original blueprint drawings. The aspect ratio of the blueprint drawings are elongated in the canyon wall upslope/downslope view. Thus, the perspective of the steepness of the left abutment slope is masked. Also, this cross section of the upslope/downslope view of the canyon is the "trench" slope excavation final sloping. A large abutment of rock had to be blasted away to form the a smooth upward slope junction to the core block. However, the steep left abutment slope remained and is not part of this blueprint elevation drawing. The drawing only shows the "trench" elevation progression. Look at the upthread picture and see the sharp "hole" or drop off downstream of the junction of the "trench".

Original Blueprint of the Earthen Dam - marked up with notes on features of the compacted Zone Fill design - Clayey core material deposited in 10 inch lifts & compacted "to a density -by weight- equal or better than concrete" (pre-hydrated for "consolidation" compaction). Zone 3 Shell layer deposited in 2 ft lifts & compacted.

[meyer]

Perfect illustration. Thanks!

[mad_as_he$$]

Welcome to Clay Pit State Vehicular Recreation Area!

Clay Pit SVRA is located two miles west of the town of Oroville. This 220-acre SVRA provides a fenced open riding area for motorcycle, ATV, and 4x4 recreationists. Clay Pit, a large shallow depression (pit) ringed with low hills, was formed when clay was mined and used in the construction of the Oroville Dam.
http://ohv.parks.ca.gov/?page_id=25572

Go to page 32:

https://www.ussdams.org/wp-content/uploads/2016/05/materials.pdf

[Ray76]

Informational meetings on the Oroville Dam situation are planned Tuesday and Thursday in Oroville, and flows are being shut down on the damaged main spillway.

DWR is hosting two meeting this week in Oroville, which will consist of an information session at 5:30 p.m., a presentation at 6:30 p.m. and then a question-and-answer period.

Tuesday’s meeting will be at the Municipal Auditorium, 1200 Myers St. Thursday’s will be at the Church of the Nazarene, Fellowship Hall, 2238 Monte Vista Ave.

The Department of Water Resources began gradually reducing the flows on the main spillway Monday morning, planning to have them stopped by 3 p.m. Tuesday. By that time, 8,000 cubic feet of water per second will be flowing through the Hyatt Powerhouse.

Inflow into Lake Oroville has generally been below 20,000 cfs. DWR was releasing 35,000 cfs before starting to scale back Monday, and the lake level had dropped to 834.71 feet when the reductions started at 9 a.m. Monday. That’s more than 64 feet below the lip of the emergency spillway’s lip.

DWR anticipates operating the main spillway once more this season.

http://www.orovillemr.com/general-news/20170501/dwr-oroville-dam-meetings-tuesday-thursday-in-oroville-spillway-flows-shut-off

[Ray76]

DWR looking to replace forensic team member

The state Department of Water Resources is looking to replace the geologist on the team looking into what caused the Oroville Dam spillway to collapse.

In a letter to David Capka, director of the Division of Dam Safety and Inspections, DWR Project Manager Ted Craddock wrote the previously selected geologist for the team could no longer fulfill his role “due to issues that arose during the contracting process.” The letter was filed Tuesday with FERC.

DWR has proposed geologist Dr. Peter Dickson as the replacement.

Dickson is a global geotechnical practice leader with Stantec and vice president of MWH, Global Inc.,acquired by Stantec last year. He has been with MWH for 39 years and has 44 total years of experience, according to his resume included with the filing.

Dickson has worked on dams and hydroelectric projects in the U.S. and around the world.

http://www.orovillemr.com/general-news/20170502/dwr-looking-to-replace-forensic-team-member

[EarthResearcher333]

Hi Ray, Interesting development - release of a Forensic Review team member. There are three names in the original selected team that could have a somewhat of a GeoTechnical/Geologist Profile match to the new proposed replacement.

I don't want to speculate on which of the three. I suspect the press will soon discover who it is.

Mr Craddock does not say much as to any indicators for a reason, which is just as well. Any issues if they arise in a team environment, sometimes are just that, issues within a team. No guarantees on the "chemistry" of assembled high power teams. It does provide an unusual situation where someone is being "released" in the midst of the intensely anticipated "Forensic Analysis". :-)

DWR to FERC letter March 2, 2017 announcing a Forensic Analysis Team member is being released. Proposed replacement's name & resume were attached to the FERC correspondence.

[EarthResearcher333]

Blasting at Upper Main Spillway - very close - Why? - Clue may be a spillway charged Water basin - but Why the Risk?

DWR photo shows a drill rig setting up an array of blast holes nearly 100ft near the Upper Main Spillway. This very close blasting is NOT for the DWR stated reason of "protection of workers" for the carved canyon as this is well upslope from the canyon walls. This blasting, so close, may likely "jar" the broken part of the spillway. Why risk more damage when there is another spill projected soon? It may be understandable in the closeness of the blasting for the vertical cliff - but this risk has seemed to be resolved by blasting that has already occurred (wider angle of this photo).

To take such a risk of destabilizing & possibly tumbling the 50+ end section of the damaged upper spillway must have a reason. But to potentially destabilize the fragile upper main spillway? I've lived adjacent to a rock quarry less than 1/4 mile away. I could hear large rock crashing through trees after blasts. We were warned before blasting & would go inside just in case. The shock to the house foundation was amazing. You felt the shock before you heard the blast (a split second difference). I can't image intentionally "shocking" the critical upper main spillway right now - especially so close - and when it is in an area that seems unnecessary.

Putting on a "wild idea" hat…. Perhaps someone wants to get ahead of the game and feels the risk is worth the head-start…. Perhaps they need to figure out a sneak drain path (possibly eroded in the hillside rock) of the large residual waterflow from a side hill basin of the spillway… If so, why can't this wait?

Blasting right next to Upper Spillway - risking destabilizing & tumbling of 50+ ft section of end of spillway - risking damage to rest of spillway - Note the significant waterflow in the drain outlets and in the damaged lower left drains on the shotcrete.

[abb]

Maybe constructing a level area for a batch plant work pad? (thinking out loud again) Maybe a batch plant on both sides of the spillway, so as to have access and delivery locations on each side?

[firebrand]

To all who are knowledgeable about the Oroville Dam:

What do you think of this guy, specifically, what he is saying in this "video"?

[meyer]

I wonder if they’re planning to use low-power blasting, deep down like they did in another area as shown in a previous video. Something to break up the weathered rock. But even that could have an effect on the bedrock under the spillway.

I hope that it’s well thought-out.

[KC Burke]

Okay, you asked for speculation. I will try.

IF they are drilling holes for blasting it might indicate the following:
1.) They are planning to cut that parallel access road down lower to the elevation of the adjacent spillway floor to provide access.
2.) They want to do that in a matter of days not weeks when they do start it.
3.) They know that area has rotten rock in one layer and then various layers of solid concomitant rock below.
4.) They are drilling to place a weak charge at a precise shallow depth in say the first solid layer so that the rotten layer and the first shallow layer peals away like a well broken egg shell.
5.) This way they get in there with big scrapers with teethed equipment ahead of it to pull all that material out and make a 15 foot cut at that roadway in a matter of days because all the material is pre-broken.

They then end up with a parallel access-way at the same elevation as the slab they want to remove when starting later this year.

This avoids the procedure where the soft material comes out and then hoe-rams have to be brought in to peck away at a new layer of removal, then excavators have to take it out in big shovel batches, etc.

Charges of precise small amounts are used to make cuts in that manner all the time when roadways are cutting across an elevation that has such rock.

Doing it adjacent to an earth-fill dam — Just Damn, I don’t know. They blast all the time when they are building these puppies — I will wait and see.

[KC Burke]

I guess I didn’t read far enough — Great minds think alike.