
Images and video showing extent of Oroville dam damage - JabavuAdams
https://imgur.com/gallery/mpUge
======
albeebe1
I really like the way those videos were presented. Silently, looping, laid out
one on top the other, each with a one line description. If that was one long
video i would have kept jumping backwards to rewatch all the scenes. Final
thought, drone footage continues to blow me away.

~~~
0003
I feel like I learned more from watching these videos than I did on many of
the numerous news articles written at the time. Granted, they were after the
fact, but wow.

~~~
sxcurry
Agreed- this is the first time I really understood the sequence of events and
the scale of the damage.

~~~
natch
These images still didn't even show the dam itself, nor the water being
released from the normal pathways in the dam, where they also had a few
problems (which I can't describe in detail due to ignorance.. I believe it was
related to backup of mud and debris from the spillway problems causing
backwash that clogged up some of the main dam works). And yet I agree, this
has been the best presentation of the event so far.

~~~
dredmorbius
The main spillway _was_ the major pathway.

There was also drainage through the hydro plant, with a maximum capacity of
slightly less than 20,000 CFS. This is given in Wikipedia's coverage:

[https://en.m.wikipedia.org/wiki/Oroville_Dam_crisis#Backgrou...](https://en.m.wikipedia.org/wiki/Oroville_Dam_crisis#Background)

~~~
maxerickson
The power plant is apparently not operable when the spillways are releasing a
large volume of water:

[https://news.ycombinator.com/item?id=13785549](https://news.ycombinator.com/item?id=13785549)

There is also the issue they are addressing now where debris has blocked water
from exiting the power plant pool, preventing operation of the power plant.

If they can get the power plant running things will be much improved, as they
will be able to continue to drain the reservoir without further erosion of the
main spillway and also until it is below the level of the main spillway (which
will stop the small amount of water that is currently leaking through the
control gates).

~~~
uxp
One of the six turbines went operational sometime yesterday (Friday, Mar 3).
They are hoping to get a second online by today.

[https://ww2.kqed.org/news/2017/02/07/engineers-assess-
spillw...](https://ww2.kqed.org/news/2017/02/07/engineers-assess-spillway-
problem-at-oroville-dam/)

------
patrickg_zill
Oro = "gold" ville = "town"

California had a gold rush - part of the gold mining was done using "hydraulic
mining", where you use water to scrub away rock and direct it into a channel
for the runoff to be run through mining equipment.

Be sure, there are plenty of gold prospectors downstream panning or perhaps
even using metal detectors in the areas where the waters have receded, looking
for golden flakes ("flour") and nuggets.

I don't know the exact law in CA but in general you can use human-powered
methods without mechanical assistance, to pan for gold (basically what looks
like a pie-pan which has ridges inside to catch the heavier gold).

~~~
socialentp
That was my thought exactly, but I was less eager to share. Gold is often
found in association with serpentine (I would bet that has something to do
with it being California's state rock) and I saw a lot of serpentine in that
gouge caused by the side offshoot. Oroville is not too far from Sutter Mill,
where gold was first discovered in California. The Feather River is one of the
main river systems in what is known as the 'Mother Lode' area of California
(yes, that is where that phrase comes from).

~~~
HillaryBriss
minor footnote: serpentine is interesting as the state rock and a host for
gold, and also as a host for chrysotile asbestos. there was some discussion
five or ten years back about changing California's state rock to something
else because of that.

[http://www.nytimes.com/2010/07/14/us/14rock.html](http://www.nytimes.com/2010/07/14/us/14rock.html)

------
wgyn
The Oroville Dam is really a crazy undertaking when you consider: 1) it
primarily serves to move water all the way from north of Sacramento to San
Joaquin Valley / Southern California, 2) despite generating some amount of
electricity, it actually consumes 3/4 of that energy just in transporting the
water (over mountain ranges). More generally, the State Water Project (of
which the dam is a part) is the largest electricity consumer in the state of
California.

Source: [https://www.amazon.com/Introduction-California-Natural-
Histo...](https://www.amazon.com/Introduction-California-Natural-History-
Guides/dp/0520260163) (kind of "dry", but extremely informative)

~~~
floatrock
That's actually kinda beautiful from an infrastructure point of view -- the
infrastructure is self-sufficent and powered using it's own energy.

Or more accurately, it jiu-jitsu's the potential energy in the system to
redistribute the resource in a more optimal way (optimal defined as "best for
the human economy of california")

------
sikhnerd
Don't miss the March 1 update by the same guy also :
[https://imgur.com/gallery/6IyCi](https://imgur.com/gallery/6IyCi) Really
amazing to see

------
marze
What isn't discussed much in the press is how close they came to the largest
dam disaster in US history.

As you can see from the pictures, the "bedrock" under the emergency spillway
erodes quickly, even with a modest amount of water flowing over it. How would
it have handled a flow 100x larger, if the spillway structure had collapsed?

It could have easily eroded down 100 or 200 feet under the intense flow. That
would have discharged 50% of the total reservoir volume, destroying tens of
billions in real estate and possibly killing thousands.

Fortunately, the dam inflow slowed enough, combined with the main spillway
outflow, to stop flow over the emergency spillway before it collapsed. So
lucky.

~~~
ChuckMcM
I think this was intentional. A friend of mine who was a geologist working for
the Park Service before he got the coding bug and I hired him in the dot com
days told be while this was going on, "You know they are lying right?"

I asked about that and he pointed out that the dam was failing, and we were
watching it fail. He pointed out the spillway shooting sideways and the amount
of progress it had made in just the couple of days between the emergency
spillway issue and then. He drew a line on the screen showing how the water
cuts away the rocks and that the material above falls in, and becomes like
sanding bits in the water flow to cut away still more rock. He estimated that
two more weeks of rain at the levels we had experienced would result in total
failure.

None of which the press was reporting. And we talked about why that might be.
And other than the loss of life (which could be minimized by an evacuation
order) there wasn't a whole lot they could do. They certainly couldn't repair
the dam while water was flowing out of it. But at the same time they would
have a several days at least of knowing it was going to fail before it
actually did because of the amount of material that would need to be removed.

He suggested that it was in everyone's best interest to keep the panic and
stress levels low until they needed to be higher. And I can't say I disagreed
although felt it would be really annoying to have my stuff washed away when
folks knew it was a possibility and didn't even offer me the chance to move it
first.

So cross your fingers for a sunny March and a slow melt of the Sierra snow
pack.

~~~
uxp
> it would be really annoying to have my stuff washed away when folks knew it
> was a possibility and didn't even offer me the chance to move it first.

They were more concerned about getting the evacuees out of the way before they
were worried about getting the evacuees' stuff out of the way. Houses,
furniture, and belongings can be replaced after a disaster. A bunch of people
twiddling their thumbs in anxiety over a potential failure while not ordering
evacuations to minimize or prevent loss of life is potentially criminal.

Also, people tend to panic. Telling them that there is a probable problem, and
ordering a mandatory evacuation long before danger is imminent so that, if the
worst case scenario occurs, the evacuees will live gives people hope that
officials are just being overly cautious. Telling people that they have 5
hours to evacuate before it is guaranteed that all of their belongings, and
their lives, will be lost forever will cause panic and potentially loss of
life in the chaos alone.

~~~
ChuckMcM
I agree with you. The interesting question in the discussion was how you weigh
panic, economic cost, and human cost. I hope that we'll get to see the
decision tree they used at some point.

------
danbruc
Does anybody happen to know why the water flows down the spillway in waves?
Best seen right in the first GIF. I am curious what the mechanism behind that
is. Is this a general phenomenon of water flowing down an inclined plane or is
it caused by other oscillations, waves on the reservoir, resonances in the
outlet system, or something along that line?

~~~
hexane360
It basically signifies a loss of energy. You can think of it in the context of
collisions, except with a continuous distribution of fluid instead of a
discrete distribution of objects.

We know that momentum (m _v) is always conserved. In this context, we can
replace mass with cross-sectional area, because mass in a given cross-section
is proportional to the area. V is flow velocity in length /time. So momentum
is flow in length^3/time.

Energy is 1/2_m _v^2. If you lose energy, m_ v is constant and m*v^2
decreases, meaning that v must decrease and m must increase. In this context,
that means that the flow is slower with a larger area. This corresponds to an
"inelastic collision". In fluid dynamics this is a hydraulic jump.

In this situation, most of the energy loss is near the surface, so you end up
with moving hydraulic jumps on top of a laminar flow. This doesn't really
happen in natural situations, because riverbeds generally aren't this smooth.

~~~
danbruc
_This doesn 't really happen in natural situations, because riverbeds
generally aren't this smooth._

When I first noticed it, I was reminded of waterfalls, especially the way they
were portrayed in 8 bit games. [1] It turns out not to be that easy to find a
good real world example, at least not without watching hours of waterfall
footage, but this one [2] does an acceptable job showing it. I have no idea if
this could be caused by the same or at least a similar mechanism.

[1]
[https://www.youtube.com/watch?v=qfOKHuzn1Hs](https://www.youtube.com/watch?v=qfOKHuzn1Hs)

[2]
[https://www.youtube.com/watch?v=7L3m_3aRiHE&t=190](https://www.youtube.com/watch?v=7L3m_3aRiHE&t=190)

------
ghubbard
The videos these clips are taken from can be found on the California
Department of Water Resources YouTube page:

[https://www.youtube.com/user/calwater/videos](https://www.youtube.com/user/calwater/videos)

~~~
ghubbard
Juan Browne has a good series of video blogs about what is/has been going on
at the Oroville dam.

In this video from 1st March he visits the site and surrounding areas and
talks with some of the engineers working on the project:

[https://www.youtube.com/watch?v=ilkU_ivYTqQ](https://www.youtube.com/watch?v=ilkU_ivYTqQ)

------
lvspiff
Seeing what was done here in the matter of days make you realize how things
like the Grand Canyon formed over millions of years - then wonder how it isn't
bigger. Can't imagine the wealth of knowledge that has been been gained by
just watching the erosion patterns as the failure evolved.

~~~
arethuza
As far as I understand it the Grand Canyon is an example where the river
(roughly) stayed in the same place it was the land that uplifted around it.

There are examples where rivers are much older than the mountains they pass
through - like the Susquehanna:

[https://en.wikipedia.org/wiki/Susquehanna_River](https://en.wikipedia.org/wiki/Susquehanna_River)

~~~
euyyn
The land might have uplifted, but the river still had to carve the same depth
nonetheless. I don't think the land happened to raise just on both sides of
the river and not below it.

~~~
arethuza
Yes, of course the river has to erode away the rising land but it is staying
roughly where it is rather than digging down through land that isn't rising.

------
ben1040
That scour reminds me of what happened after the Taum Sauk hydroelectric
reservoir in Missouri failed in 2005, which sent 20 feet of water down a small
mountain:

[https://en.wikipedia.org/wiki/Taum_Sauk_Hydroelectric_Power_...](https://en.wikipedia.org/wiki/Taum_Sauk_Hydroelectric_Power_Station#/media/File:Tscompare.jpg)

------
OrwellianChild
I'm trying to understand context around the design of the dam spillway vs.
historical rainfall and usual flow...

Was this way more rain than it was designed for? Or was it structural failure
within design tolerances that caused all the damage?

~~~
jcranmer
There are two spillways, the main spillway and the emergency spillway.

The main spillway is the concrete spillway, and it developed a hole in late
January. Due to very real concerns that it would deteriorate, the decision was
made to use the emergency spillway until the concrete spillway would be fixed.

The emergency spillway is basically a concrete weir--when the lake level
reaches a certain height, it spills out over concrete and runs down the
hillside. This is considered an emergency spillway, and erosion is usually
expected for such spillways (the regulatory definition of an emergency
spillway is basically "it can be used once and then it needs a long downtime
while it's repaired).

When the emergency spillway was in use, what happened was the very same
erosion that was underpinning the main spillway was also occurring near the
concrete weir. If left unchecked, the fear was that it would start eroding the
concrete weir leading to potential collapse of the concrete weir. This
prompted the decision to evacuate as much water as possible using the damaged
main spillway which greatly exacerbated the damage (as the pictures show, a
large section of the spillway now fails to exist, and it looks like most of
the lower spillway would need to be torn up instead of being unused).

I'm not a geologist, and I certainly don't have detailed nature of the local
geology. But my suspicion is that the prolonged drought followed by the
intense wet season destabilized the slope (by weakening the organic
stabilization of the slope and then loading it heavily with water), so
spilling any dam water anywhere on it would lead to massive erosion (including
undermining the concrete structures). The emergency spillway is supposed to be
able to carry far more water loads. I don't think the severe-drought-then-
extreme-rain scenario was envisioned during the dam construction (although it
really should be after this event), so I don't know if the spillway would have
performed as badly in "expected" conditions.

~~~
jfoutz
Also not a geologist, and not familiar with local geology. Packing so much
water in a very small channel really helps water erode anything. If i remember
correctly, it's thought Niagara falls moved a few miles in a day. That seems
terrifying to me, it's a long drop down. Waterfalls slowly work their way
upstream, obviously. Less obviously, a little weakness lets more water though,
compounding the abrasive effects. Which allows more water, which cuts away the
land faster.

So yeah, i don't think the dryness had anything to do with destabilizing
anything. Water is just really good at cutting. The dam created a huge reserve
of water, so lots is available to cut.

~~~
simplemath
There's a similar theory regarding the formation of the Grand Canyon

[http://www.icr.org/research/index/researchp_sa_r02/](http://www.icr.org/research/index/researchp_sa_r02/)

~~~
emmelaich
Is this paper from the Institution for Creation Research well regarded outside
the institution?

~~~
dredmorbius
No. No it is not. Not at all.

[https://en.m.wikipedia.org/wiki/Institute_for_Creation_Resea...](https://en.m.wikipedia.org/wiki/Institute_for_Creation_Research)

------
zodPod
Once the water goes away, the scene is reminiscent of something from Minecraft
when someone gets too TNT happy... This is nuts thanks for sharing OP!

------
ruminasean
Wow. This was gorgeous, thorough and horrifying. Thanks for posting.

------
dredmorbius
As I've commented at length just now, this is an excellent set of
visualisations of the damage, and history, of this story. It exceeds all media
coverage I've seen of the event (though I've not canvassed all of that
coverage).

I'd like to also present Wikipedia's article on the Oroville Dam Spillway
Crisis of 2017, which is another example of exemplary coverage, and what's
been a consistent model for me for vastly better coverage of ongoing large-
scale events since the Boxing Day Earthquake and Tsunami of 2004, the first
time I'd followed a major story by way of Wikipedia:

[https://en.m.wikipedia.org/wiki/Oroville_Dam_crisis](https://en.m.wikipedia.org/wiki/Oroville_Dam_crisis)

In roughly 25 paragraphs, plus an SVG image essay showing the progression of
the damage, apparently original work by a Wikipedia editor, this spells out
the background, event, development, implications, and history of the failure.

Both the Imgur essay and the Wikpedia article are vastly more informative than
any news coverage I've seen. In the case of Wikipedia, much of that comes from
its ability to synthesize information from multiple sources and place it in a
coherent context. But in both cases, much of the value _also_ comes from a
focus on what I see as the salient factors, and an avoidance of fluff.

Taking a quick second look at the Wikipedia page, the one fault I'd give it is
that for someone _immediately_ affected by evacuation orders, there is
insufficient information about what routes were recommended _or deprecated_.
For that, some local news accounts (I'd read the _Sacramento Bee_ and _SF
Chronicle 's_ coverage in particular) was perhaps more useful, but only just.

I'd put hard to the press just what they see their mission as in reporting on
such events. Because, much as I appreciate the media, they fell down here.

 _Addendum:_ Brad Plumer, at Vox, has previously caught my attention as an
exceptionally good reporter. His article explaining the Oroville Dam crisis is
cited by Wikipedia, and is itself also excellent. I'm calling it out
specifically as an example of How to Do Coverage Right:

[http://www.vox.com/science-and-
health/2017/2/13/14598042/oro...](http://www.vox.com/science-and-
health/2017/2/13/14598042/oroville-dam-flood-evacuation)

------
frik
Lot's of infrastructure was built in 1950s/60s/70s. A reminder if we let rot
our infrastructure, it's not good at all. (not implying it's the case with
Oroville dam, haven't followed all news articles) Many concrete and steel
structures have a limited life-time of 60-100 years (or so). Big
infrastructure projects were built with ease back then, compare it too
overblown "paper work" nowadays (not speaking about engineering, but
bureaucracy). We should really look how asian countries excel at building
infrastructure nowadays (they nowadays build multi-level highways and bridges
in no time with ease, whereas building a bridge/tunnels in the west takes many
years and cost way too much) and look back in history how to maintain
infrastructure well over a timeframe of a few centuries. How many
1950s/60s/70s structures (big things like skyscrappers, dams, bridges,
tunnels, subways, etc) are a risk, need repair or are beyond repair and need a
replacement - is there a map? Is there a documentation about this topic or
some interesting research in this field?

~~~
frik
actually the imgur.com comments were very insightful

one of several recommended videos about the topic, this one is quite funny
even if it's very real:
[https://www.youtube.com/watch?v=Wpzvaqypav8&feature=youtu.be...](https://www.youtube.com/watch?v=Wpzvaqypav8&feature=youtu.be&t=17m44s)

------
ufo
That is the plan for the Oroville dam, moving forward?

~~~
dzdt
I wonder if they will reroute the main spillway down its new channel. That
looks like it might be easier than trying to fill the hillside back up all the
way to the previous level.

~~~
Animats
No way. Too close to the base of the dam itself. If anything, it might be
rerouted northwest, away from the dam.

------
jmspring
Currently living up in the Sierras along the Feather River, it's no surprise
the amount of water that went rushing down into the Oroville reservoir. Even
at about 4500 feet, you had about 3-4 feet of snow that ended up being melted
by a significant amount of rain.

That is quite a bit of water rushing down that way.

Interesting times and the videos are quite educational.

------
olivermarks
the latest is that the banks of the Feather river have collapsed after the
huge amounts of water receded. Amazing the power of water... "With high water
no longer propping up the shores, the still-wet soil crashed under its own
weight, sometimes dragging in trees, rural roads and farmland, they said.

“The damage is catastrophic,” said Brad Foster, who has waterfront property in
Marysville (Yuba County), about 25 miles south of Lake Oroville.

The farmer not only saw 25-foot bluffs collapse, but also lost irrigation
lines to his almonds. “When the bank pulled in,” he said, “it pulled the pumps
in with it. It busted the steel pipes.”

[http://www.sfchronicle.com/bayarea/article/Riverbanks-
collap...](http://www.sfchronicle.com/bayarea/article/Riverbanks-collapse-
after-Oroville-Dam-spillway-10976144.php)

------
abpavel
A classical "we've found a problem. let's fix it later, when it will be too
late" approach to infrastructure.

I'm sure there will be dozens of "good reasons" why the repairs could not have
been done in time, but the theme of the approach to infrastructure problems is
disheartening.

------
nkkollaw
Nature is pissed off.

------
getpost
So they built a big strong dam and a "protected" it with a smaller, weaker
dam. Seriously, what was the rationale for this design? No criticism or Monday
morning quarterbacking here. I'm genuinely curious what the original engineers
were thinking.

~~~
getpost
Looks like oasisbob answered, thanks!

~~~
dredmorbius
Specifically here, and it's an excellent comment:

[https://news.ycombinator.com/item?id=13785435](https://news.ycombinator.com/item?id=13785435)

------
maxerickson
When the evacuation was announced I sort of hastily pasted into a chat channel
that the dam was going to fail.

The main dam of course did not fail, but looking at the recent photos, the
overall system sure did fail. I hadn't realized the extent to which the
spillway had continued to erode.

~~~
mikeash
There's basically no chance of the main dam failing. A failure of the
emergency spillway is basically the worst case scenario. For the main dam to
fail, water would have to get over the top, and the emergency spillway ensures
that the lake stays below that level.

A failure of the emergency spillway would still be quite destructive, of
course.

~~~
maxerickson
Sure, I understand, I've posted as much in previous discussions here.

Having the main spillway continue to erode is pretty clearly a failure state
of the dam system.

~~~
oasisbob
_...a failure state of the dam system._

One thing I'm really impressed with is how many redundancies are built in to
dams, and how their failures are intended to be gradual and not catastrophic
and sudden with a full release of the reservoir contents.

ie, use the water to generate electricity. If that's not enough outflow, use
the spillway. If the spillway isn't enough, the emergency spillway will drain
more.

There's even another contingency (with more details), described here, that I
haven't heard anywhere else:

[http://blogs.agu.org/landslideblog/2017/02/14/oroville-
dam-s...](http://blogs.agu.org/landslideblog/2017/02/14/oroville-dam-
site/#comment-214014)

> The emergency spillway is not auxiliary, and i don’t believe any competent
> geologist present during it’s construction would have considered its use as
> anything but a last ditch effort. It was designed as a fail-safe to prevent
> the loss of the main dam during the event of a half a million cfs inflow to
> the lake during a 200 to 1000 year event. The ogee weir extending from the
> main spillway gates was likely built to protect the main spillway gates. The
> bedrock was excavated deeper below the ogee weir to find more competent
> bedrock than the concrete wall extending northwards from the ogee weir,
> which was built to protect the ogee weir. The lack of concrete in the far NW
> corner of the parking lot where we saw considerable erosion and helicopters
> lowering bags of rocks into is not lack of foresight, but designed weakness
> built into a weak structure. The parking lot is built on highly weathered
> bedrock and is designed to function as a sacrificial plug located as far
> from the dam itself as possible, similar to the Auburn coffer dam failure of
> 1986. As headcutting progresses into the parking lot, water at elevation 900
> and above is skimmed off. Once headcutting reaches the lake, then
> downcutting commences, “safely” lowering the lake till competent bedrock is
> found, maybe a hundred feet down, leaving the vast majority of the lake
> still in the lake and Oroville dam still standing, no matter the magnitude
> of the storm.

~~~
Animats
The normal water exit from the dam is through the power plant. If either
spillway is moving too much water, the level of the pool below rises, and the
power plant turbines can't run because there's backpressure at their exit.
That happened this time, which increased the load on the spillway.

Right now, the lake level has been dropped to 50 feet below the dam top, to
provide some safety margin for later storms. The crisis is probably over, and
there will be heavy construction this summer.

