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Oroville Dam Spillway Concrete Failure (Feather River Flooding, CA) 36

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msquared48

Structural
Aug 7, 2007
14,745

Erosion has created a 300-foot-deep hole in the concrete spillway of Oroville Dam and state officials say it will continue grow.
State engineers on Wednesday cautiously released water from Lake Oroville's damaged spillway as the reservoir level climbed amid a soaking of rain.

Situated in the western foothills of the Sierra, Lake Oroville is the second-largest manmade reservoir in California after Shasta....

Member Spartan: Stage storage flow data here for those interested:

Mike McCann, PE, SE (WA)
 
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when the dam was originally constructed I believe it was recommended that they had 50 foot pylons, but things changed as money was spent. On a more disturbing note during initial construction, "while pouring cement the earth was eroding away so much that a worker stopped and refused to keep pouring until the foreman came by and started work again"... That decision saved them 10% cost. You see they didn't want to go over budget, apparently their financial calculations were inaccurate.


When the water way started to fail in 2017, it created a massive 30+ foot deep hole... fast forward to 2019, they've added 25 foot deep pylons. Anyone see what im seeing??


And now for the worst offense: the old design supposably could handle 160,000 cfs BUT it started to rip apart nearing 90,000 cfs. The old design never flowed above 100,000cfs it just started falling apart.. lets hope the new design's calculation of 270,000 cfs can be trusted for at least ~160,000 cfs.


forgive me if I'm skeptical of their calculations, they seem to really not hold water. on the news the heads of multiple departments were saying "it's okay, its okay"... In the meetings they were really debating whether or not to evac the whole california valley, while the boils were growing underneath...


it's a little early to declare victory or success, this season is proving to be one of the wettest since the 1990s
 
pre_engineer said:
When the water way started to fail in 2017, it created a massive 30+ foot deep hole... fast forward to 2019, they've added 25 foot deep pylons. Anyone see what im seeing??

That "massive 30+ foot deep hole" has been filled with roller-compacted concrete, which in essence has created 'new bedrock' into which the pylons are now anchored.

John R. Baker, P.E. (ret)
EX-Product 'Evangelist'
Irvine, CA
Siemens PLM:
UG/NX Museum:

The secret of life is not finding someone to live with
It's finding someone you can't live without
 
pre_engineer said:
Anyone see what im seeing??

No, I'm not at all. But then you're not posting any actual proof of issues or design errors, just claims it can't be right just 'because'.

On another note, where'd your quote come from? You must have a source you can link.
 
And I would think that the next time the weather is clear (and today's starting to look pretty nice up there) that Juan Browne will be up in the 'Mighty Luscombe' taking some videos of his own.

John R. Baker, P.E. (ret)
EX-Product 'Evangelist'
Irvine, CA
Siemens PLM:
UG/NX Museum:

The secret of life is not finding someone to live with
It's finding someone you can't live without
 
Pre-Engineer -

Some responses to your comments / negativity about the performance of Oroville.

1) The Dam / Spillway was constructed in 1967. So, it performed adequately for 50 years. At least the dam has with no real problems noted.
2) The spillway clearly had some problems for years leading up to the failure. Were these initial design flaws? Or, were these flaws with maintenance where they didn't adequately fund necessary maintenance / repairs over the previous 50 years? My guess is that it's a little of both.
3) It's way, way too early to claim design flaws in the new spillway.... unless you were part of the actual design process and know a lot more than the rest of us. It seems to me, as an outsider, that there was a really strong effort to address all possible design issues with the old spillway in the design and construction of the new one.
4) The emergency spillway had an inherent design flaw. I will grant you that. But, that appears to have been totally remedied with the new design / re-build.
 
And also keep in mind that until 2017 when the level of the reservoir topped 901 feet, at NO time since the dam had been constructed in 1967 had any water ever gone over the emergency spillway, and while there were obvious problems with the emergency spillway, as noted previously, it again was never an issue for 50 years. But like a lot in engineering, until a failure occurs, there is very little that could have been done to anticipate the consequences. After all, back in 1967, when it came to structures like dams and spillways, the most common tool used for analysis was based on creating physical hydrology models which could only show just so much detail as to what might happen under different conditions.

To that point, back while I was in engineering school, a group from our Army ROTC class visited the Corp of Engineers facility in St. Paul, Minnesota where they had created hydrology models for the most all of the northern Mississippi River including several larger models of specific flood-control projects that were currently being proposed and planned. Here's a photo that I took showing one of those models of a proposed project:

AE-099_f0fwzg.jpg

October 1968 (Minolta SR-1)

John R. Baker, P.E. (ret)
EX-Product 'Evangelist'
Irvine, CA
Siemens PLM:
UG/NX Museum:

The secret of life is not finding someone to live with
It's finding someone you can't live without
 
Apparently the level of the Oroville reservoir is back down to where they no longer need to use the spillway:

Screen_Shot_2019-04-10_at_4.40.06_PM_y0q9bw.png


For the live link, go to:


And here's a shot showing the backside of the dam where we can clearly see the water level:

Screen_Shot_2019-04-10_at_4.46.45_PM_xxczxn.png


John R. Baker, P.E. (ret)
EX-Product 'Evangelist'
Irvine, CA
Siemens PLM:
UG/NX Museum:

The secret of life is not finding someone to live with
It's finding someone you can't live without
 
It's actually not 'going down' (it's actually gone up) but you are right that they aren't using the flood control spillway anymore to control the level, just the power plant.
There is a flood control plan they use to figure out when to open the spillway.
You can see the current level as well as historically how they have managed the level in the graph below. You can see the divot when they had it open last week.

Screen_Shot_2019-04-11_at_3.21.59_PM_qav5fu.png



 
It appears that they've diverted the minimal runoff from the spillway so as to allow what appears to be some addition work or at least some inspections of the spillway surface. I've been watching this for a couple of days now and there have been times when you could see several workers walking around on the face of the spillway, and doing stuff near some of the seams, particularly near where the spillway starts to take a more severe drop down toward the Feather River.

Screen_Shot_2019-04-18_at_1.16.37_PM_mps4o4.png


John R. Baker, P.E. (ret)
EX-Product 'Evangelist'
Irvine, CA
Siemens PLM:
UG/NX Museum:

The secret of life is not finding someone to live with
It's finding someone you can't live without
 
Juan Browne just posted a brief update where he talks about the spillway inspection and how this activity has been reported by the so-called trolls as proof that the money was wasted on the repair and that there are further problems with the dam.


John R. Baker, P.E. (ret)
EX-Product 'Evangelist'
Irvine, CA
Siemens PLM:
UG/NX Museum:

The secret of life is not finding someone to live with
It's finding someone you can't live without
 
It appears that authorities are allowing Lake Oroville to continue to rise. It's currently over 885 feet, which puts it just 16 feet or so from topping the emergency spillway. Could they be planning some sort of test of the emergency spillway, to perhaps to verify how the water would drain?


John R. Baker, P.E. (ret)
EX-Product 'Evangelist'
Irvine, CA
Siemens PLM:
UG/NX Museum:

The secret of life is not finding someone to live with
It's finding someone you can't live without
 
John:
It looks like it is routine for them to take it right up to the top:

That’s from 2012 where they ran it up to 898.97. They had it up to 890 in 2016 as well.

It’s there to store water after all. My guess is they watch the short and long term forecast and only dump water when it looks like there’s a massive influx coming down the pipe.
 
There is a lot more head on the gates than there was.
 
Juan Browne posted a short update on the status of the Oroville dam's water-level as well as some info on the current snow-pack in the Sierras:


John R. Baker, P.E. (ret)
EX-Product 'Evangelist'
Irvine, CA
Siemens PLM:
UG/NX Museum:

The secret of life is not finding someone to live with
It's finding someone you can't live without
 
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