Expert: What You Need To Know About The Oroville Dam Crisis

News & Current Events Public News & Current Events
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To make sense of the fast-developing situation at California's Oroville Dam, Chris spoke today with Scott Cahill, an expert with 40 years of experience on large construction and development projects on hundreds of dams, many of them earthen embankment ones like the dam at Oroville. Scott has authored numerous white papers on dam management, he's a FEMA trainer for dam safety, and is the current owner of Watershed Services of Ohio which specializes in dam projects across the eastern US. Suffice it to say, he knows his "dam" stuff.

Scott and Chris talk about the physics behind the failing spillways at Oroville, as well as the probability of a wider-scale failure from here as days of rain return to California.

Sadly, Scott explains how this crisis was easily avoidable. The points of failure in Oroville's infrastructure were identified many years ago, and the cost of making the needed repairs was quite small -- around $6 million. But for short-sighted reasons, the repairs were not funded; and now the bill to fix the resultant damage will likely be on the order of magnitude of over $200 million. Which does not factor in the environmental carnage being caused by flooding downstream ecosystems with high-sediment water or the costs involved with evacuating the 200,000 residents living nearby the dam.

Oh, and of course, these projected costs will skyrocket higher should a catastrophic failure occur; which can't be lightly dismissed at this point.

Scott explains to Chris how this crisis is indicative of the neglect rampant across the entire US national dam system. Oroville is one of the best-managed and maintained dams in the country. If it still suffered from too much deferred maintenance, imagine how vulnerable the country's thousands and thousands of smaller dams are. Trillions of dollars are needed to bring our national dams up to satisfactory status. How much else is needed for the country's roads, railsystems, waterworks, power grids, etc?

Both Chris and Scott agree that individuals need to shoulder more personal responsibility for their safety than the government advises, as -- let's face it -- the government rarely admits there's a problem until it's an emergency. Katrina, Fukushima, Oroville -- we need to critically parse the information being given to us when the government and media say 'it's all under control', as well as have emergency preparations already in place should swift action be necessary.

Click the play button below to listen to Chris' interview with Scott Cahill (47m:13s).

This is a companion discussion topic for the original entry at https://peakprosperity.com/expert-what-you-need-to-know-about-the-oroville-dam-crisis/

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Great episode. Really glad you decided to cover this fascinating story as it unfolds. Great job getting Scott Cahill, who seemed like a real expert, on the show.
You briefly mentioned the 2005 FERC relicensing proceeding where Friends of the River, Sierra Club, and SYRCL raised concerns over the unarmored emergency spillway and predicted the erosion that precipitated the evacuation yesterday. This story was originally broken by The Mercury News and more recently covered by The Washington Post.
What I found disturbing about the media coverage was that none of the articles actually linked to the filing. I could not agree more that individuals must take responsibility for themselves. Accurate first-hand information is critical to making the right decisions. However, the media rarely links to its sources giving readers little more than a few quotes to base judgments on.
Anyways, I dug the source document out of the FERC website and posted it to Scribd. What I found most damning about this Motion to Intervene was the final page where the emergency spillway is aptly called an unarmored “spillway without a spillway” and hillside erosion is suggested as a likely consequence. The State Water Contractors responded with the sole argument that Friends of the River didn’t prove erosion would occur. But shouldn’t the burden of proof be flipped? Oroville Dam should be provably resilient rather than unproven deficient.

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On second thought, helicopters dropping boulders and sandbags sounds like a really good idea.

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Time2Help,
Wow, that’s the best picture yet that shows why they are so worried about any more water going over the “emergency/auxillary” spillway.

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“This is the first time water has risen to this level in the history of this dam.”
“This will be the first activation of the emergency spillway.”
When I heard him say this, it got my attention. Until an item or a process has been actually tested, you have no idea if it will actually work. Ideally, you never want to be the first person or group to go through an “error condition” or situation.
Awesome interview. I really enjoyed the guest’s perspective. You don’t really want an optimistic engineer working for you. Instead, you want a cranky, pessimistic one, that thinks that everything is probably going to fail. That raises the level of operational stress you are under, but the chances of actual failure go way down. That’s my perspective anyway. I’ve dealt with both kinds of thinking, and as a manager, I was always much more worried about the optimistic engineer’s projects. I knew from my own experience that if they weren’t worried, then they weren’t really that aware about how complex the whole thing actually was, and all of the possible failure modes it might have.
I was always pleasantly surprised when my code went an entire release without some big problem happening that was traceable back to my component. I wonder sometimes if the people who design planes are actually comfortable flying in them. They know all too well just how many things can go wrong. When the news breaks that a plane has actually gone down, I’m willing to bet that each engineer is secretly praying that it wasn’t their subsystem that failed and caused the crash.
You can be sure it wasn’t a cranky engineer who called it an “auxiliary” spillway. That had to have been someone in Public Relations. Or Marketing.

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You need a strong mesh there. You get all the prestressed piles and girders you can, steel girders too. You fly them in there, and then with early-strength concrete you bind them together and drop them in place into a giant truss. wherever you can, you bolt them together. Where you can’t, rebar plus concrete will do.
Then with the truss, you fill in with smaller elements, a mesh across that. then smaller again, your final layers are – what? You need an elastic wall. I might well go for wood on the outer layer.
Then you drain the entire thing, and rebuild it right.

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I’m not a “dirt engineer”, my field is elsewhere, but Fairfax is right on with the Cranky Engineer paradigm. Alas, they are often ignored. Cranky engineers (I am one of them) know and believe that everything has failure potential, and usually multiple failure modes, and push for design margins to cover contingencies. It is always a tension between the funding money and making a system as robust as forseeably possible. This is how Fukashimas (and apparently Orovilles) happen.
I understand cost constraints too, but safety-critical systems deserve extra attention.
It especially disturbs me that,if this issue winds up turning on cost decisions, that there will be nobody at all held accountable due to the “those decisions didn’t happen on my watch” aka widely distributed accountability syndrome.
I wonder if there will be an Erin Brokovich type dirt engineer coming forward at any point with some answers. In the meantime, I hope the thing doesn’t go completely off the rails before they can get a maintenance availability to patch it. I understand there is a bit of rain coming up in the region.
m

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I heard that erosion rate supposedly has a cube relationship to volumetric water flow (another one of those exponential things!). Can anybody here confirm or expand that? Haven’t listened to the podcast yet, going to do that as soon as I have a few minutes.

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An hourly log of the water level at the Oroville Dam can be found at this URL:
http://rdcfeeds.redding.com/lakelevels/oro.cfm
As of 10am PST this morning, the level was at 887.94 feet:

The plan on the ground at the dam is to try to get the lake level to 850 feet before the rains start up on Thursday.

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A source on the ground at the Oroville dam has sent us these images (taken approximately at 10:30am PST 2/14/17).
Water flowing down the primary spillway (video). Volume is still high, but it looks like there's a lot less sediment in the water, meaning less erosion of the berm going on. That's likely a good sign:

A closer shot of the primary spillway: Helicopters have begun dropping the 1-ton bags of crushed rock to the weak spots on emergency spillway: Video of the Feather River as it runs through the town of Oroville. Still lots of sediment here, which is wreaking havoc on downstream fisheries and ecosystems:
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The carrying capacity. (Erosive capacity) of water varies as a cube of its velocity.
Given infinite funds therefore ( or even funds diverted from gender alignment surgery) the spillway should follow the contour lines until it finds an entry to an underground aquifer.

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From our source (an anonymous command team member) on site at Oroville:
The debris from the erosion in the primary spillway, combined with the debris from the use of the emergency spillway, has collected where those spillways run off into the Feather River.
This is causing the waters to back up towards the dam itself, and have flooded the power station there. In addition, a wall associated with the power station is about to fail, which will add to the damage/destruction to the facility.
So now things have become a lot worse:
The power station is not going to be operational again for a long time. And will likely be very costly to repair/rebuild.
The 17,000 cfps outlet for the dam located near the power station is now no longer an option. Given that, and given that the emergency spillway is in such dire shape, the compromised primary spillway is now the only option for reducing the water level behind the dam.
The turbulence of the waters swirling around the spillway debris may likely increase the erosion factor of the dam’s earthen berm, increasing the odds for a catastrophic failure.
We’ll report more as we learn of it.

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Chris:
Thank you so very much for having me on your podcast about the Oroville dam and issues of infrastructure and the national dam inventory. I had a wonderful time and truly appreciate the opportunity to talk to your community and to become a part of it.

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California state officials just announced that they are lifting the evacuation order from towns downstream of the Oroville dam:

“Any resident displaced by the evacuation may return home at 1:00 pm; however all residents are advised to remain vigilant and prepared as conditions can rapidly change. People who have special needs or require extended time to evacuate should consider remaining evacuated,” said the announcement, issued by Sheriff Kory Honea.
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Scott Cahill wrote:
Chris: Thank you so very much for having me on your podcast about the Oroville dam and issues of infrastructure and the national dam inventory. I had a wonderful time and truly appreciate the opportunity to talk to your community and to become a part of it.
Scott, that was a great interview and very helpful to all who listened to it. Thank you for your candor, expertise and availability!
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Adam:
This is a failure mode that I had discussed some time ago in my writing. The eventuality of this flooded toe of the dam is erosion of the embankment. As the pool beneath the dam forms, and the spillway remains actuated, the pool will begin to rotate counter-clockwise. This will cause erosion of the toe of the dam, the power house area, and depending on the specifics, potentially significant erosion of the downstream face. The spillways will be needed again in force if the rain that is anticipated comes. The possibility of renewing the evacuation and of a possible event is very real.

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It’s all safe now. Expect heavy traffic on the way back in to town. The spillway has been thoroughly inspected. It wasn’t the government’s fault. Doubleplusgood!
https://www.google.com/amp/www.cnbc.com/amp/2017/02/14/authorities-lift-…

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Adam Taggart wrote:
From our source (an anonymous command team member) on site at Oroville: The debris from the erosion in the primary spillway, combined with the debris from the use of the emergency spillway, has collected where those spillways run off into the Feather River. This is causing the waters to back up towards the dam itself, and have flooded the power station there. In addition, a wall associated with the power station is about to fail, which will add to the damage/destruction to the facility. So now things have become a lot worse: The power station is not going to be operational again for a long time. And will likely be very costly to repair/rebuild. The 17,000 cfps outlet for the dam located near the power station is now no longer an option. Given that, and given that the emergency spillway is in such dire shape, the compromised primary spillway is now the only option for reducing the water level behind the dam. The turbulence of the waters swirling around the spillway debris may likely increase the erosion factor of the dam's earthen berm, increasing the odds for a catastrophic failure. We'll report more as we learn of it.

Oh, well this explains why they’d lift the evacuation. Ugh.

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When considering infrastructure costs, long term planning is essential and should come with current tracking of hydraulic dynamics. Whether dam building, road building, irrigation plans, what have you; watershed criteria needs to be seriously considered. We only need the historical evidence of the fertile crescent, China’s environmental crisis, Easter Island, Greenland’s demise in the middle ages, and other human induced catastrophes that result from pushing nature beyond her established limits. As human population continues to expand, we can only hope that we become more diligent in considering ALL the facts before economics forces us off the trail. Consider:

The amount of sediment carried into a reservoir is at its highest during floods: in the US, for example, commonly half of a river’s annual sediment load may be transported during only 5 to 10 days flow. During and after a particularly violent storm a river may carry as much sediment as it would in several "normal" years. Mudslides caused by earthquakes and volcanoes can also have a dramatic and unpredictable effect on reservoir sedimentation. Global warming, which is predicted to cause more intense storms, will likely increase both the unpredictability and rate of reservoir sedimentation.
From : https://www.internationalrivers.org/sedimentation-problems-with-dams
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Thank you Scott, for sharing your expertise with us.
m