
Areas near Sacramento evacuated as Oroville spillway collapse feared - akaru
http://www.sacbee.com/news/state/california/water-and-drought/article132332499.html
======
ENOTTY
I looked for more information about this situation. LAT has a live blog that
seems to have some really good info about the dam, the spillways, and the
damage in the early posts to the live blog
[http://www.latimes.com/local/california/la-live-updates-
orov...](http://www.latimes.com/local/california/la-live-updates-oroville-dam-
how-the-oroville-dam-situation-became-a-1486958195-htmlstory.html)

~~~
Animats
The main spillway is out of action due to major erosion damage in its concrete
flume. The power plant is shut down because the water level at the low end, in
the diversion pool, is too high. So the two normal ways of releasing water are
out of service. The emergency spillway is just a dirt hill near the dam with a
concrete lip at the top.

There's a data feed from sensors at the dam.[1] "Level" is probably good data.
"Out" flow rate may not be meaningful; the emergency spillway probably lacks a
flow meter. Here's a plot of "Level".[2] When it's below 900, the auxiliary
spillway should stop flowing. As of 2330, it's at 900 feet almost exactly.

[1]
[http://rdcfeeds.redding.com/lakelevels/oro.cfm](http://rdcfeeds.redding.com/lakelevels/oro.cfm)
[2]
[http://cdec.water.ca.gov/jspplot/jspPlotServlet.jsp?sensor_n...](http://cdec.water.ca.gov/jspplot/jspPlotServlet.jsp?sensor_no=1148&end=02/12/2017+23:31&geom=small&interval=2&cookies=cdec01)

~~~
maxerickson
The main spillway was open last night, carrying 100,000 cu ft/s of water
(comparable to Niagara Falls). I guess it is still open, but I only spent a
minute trying to find a current source.

They had reduced the main spillway flow prior to water starting to flow out
the emergency spillway, but they increased it after that happened.

edit: it seems that the water level is below the emergency spillway now, but
the main spillway is still open, probably at least partly out of concern about
coming rain.

------
rodionos
Current Storage vs Capacity Levels:

[https://apps.axibase.com/chartlab/dee79515](https://apps.axibase.com/chartlab/dee79515)

The overflow lasted for 45 hours.

The water level appears to be dropping quickly at the moment:

[https://apps.axibase.com/chartlab/dee79515/2/](https://apps.axibase.com/chartlab/dee79515/2/)

~~~
anotheryou
Overflow means the actual spilling over the top (the emergency spillway) on to
hill and street below? So we still have the broken main spillway in action or
not?

~~~
chrishacken
It's not just flowing over the top of the dam; the water is channeled through
an area designed to handle overflow; but the channel is damaged.

See pic:
[http://s4.reutersmedia.net/resources/r/?m=02&d=20170213&t=2&...](http://s4.reutersmedia.net/resources/r/?m=02&d=20170213&t=2&i=1172421238&w=&fh=&fw=&ll=780&pl=468&sq=&r=LYNXMPED1C0CT)

I believe they're worried about the erosion tearing apart the hillside and
thus destabilizing the entire hill; at which point the whole hill would just
collapse.

~~~
rebootthesystem
What I've been wondering is: What, if anything, did they do during all of
these years of drought in order to ensure dams and all required mechanism
remained sound and ready for when rains returned?

The lake near my house was down 120 feet. You could see land and structures
never seen in decades. Prime opportunity to get in there to inspect and
maintain said infrastructure. Not sure anything was done at all.

I am no expert in concrete but I would like to think the break in the Oroville
spillway could have been detected and dealt with with cursory inspections over
the last several years, when access was easy due to the drought.

I don't like it when folks are put in danger because other folks who are
supposed to be working for us don't do their jobs. Not saying this is what's
happening here, I don't know, but the question needs to be asked.

~~~
maxerickson
The spillway can be completely shut during normal operation of the dam. So the
drought didn't provide any increased opportunity to do inspections.

~~~
rebootthesystem
It did in the sense that you could undertake projects that would be impossible
had the lake been full. In other words, you had certainty of not needing the
spillway for months/years.

~~~
maxerickson
It's pretty impossible to predict that the spillway won't be needed in a given
wet season.

They share the data about the level of the reservoir:

[http://cdec.water.ca.gov/histPlot/DataPlotter.jsp?staid=ORO&...](http://cdec.water.ca.gov/histPlot/DataPlotter.jsp?staid=ORO&sensor_no=6&duration=D&start=02%2F03%2F2008+06%3A11&end=02%2F13%2F2017+06%3A13&geom=Small)

The wet season last year basically filled the reservoir up from its lowest
levels. So a project started in the middle of 2014 would need to leave the
system operable by December, and they have that same ~6 month period in pretty
much every year.

~~~
rebootthesystem
The point is they had 6 to 10 years (however long the drought lasted) to get
ready for this moment in time, even if a little bit at a time.

Nobody ever seems to do this. We always wait for disasters before fixing or
maintaining anything. This, despite the fact that we pay taxes, plenty of
taxes, to fully staff, train and employ departments with thousands of people
who are supposed to actively be looking after these things.

It's the infrastructure equivalent of a sysadmin who never looks after
security and then, when all hell breaks loose, proclaims we need to do
something about security.

~~~
maxerickson
Sure, but my point is that they have the same opportunity to do inspection
whether there is a drought or not. So they've had the lifetime of the dam to
do inspections and maintenance, not just a few years.

There's lots of possibilities. Maybe they didn't do inspections last year.
Maybe they did inspections and noted damage that did not yet warrant repair.
Maybe they did inspections and missed damage. Maybe they were unable to secure
funds to repair the damage. Maybe the damage was noted too late to do repairs
last fall. Etc.

The thing to do is wait and see if they come forward with a reasonable
explanation of what went wrong and then feed that information into the
maintenance plans at this dam and others.

------
jordache
This is reminisce of the spillway problem at the Glen Canyon Dam
[https://www.youtube.com/watch?v=dHpKvQ9XHV4](https://www.youtube.com/watch?v=dHpKvQ9XHV4)

[http://www.hcn.org/external_files/40years/blog/NearBreachGle...](http://www.hcn.org/external_files/40years/blog/NearBreachGlenCanyonDamArticle.pdf)

It's a fascinating read.

I'm sure the California folks right now are studying up notes from the Glen
Canyon incident.

~~~
pilom
Glen Canyon was slightly different because there was no "emergency spillway"
in the same way that Oroville has. Glen Canyon simply had 2 giant spillways
that both needed to be in use but were both getting torn apart by cavitation.
They ended up adding plywood along the top of the spillway gates to give
themselves a little more reservoir capacity to wait out the flooding upstream
but honestly they just got lucky. The only option they had at Glen Canyon if
they exceeded the plywood barrier would have been to let water flow down the
main spillways and possibly damage the dam.

------
bshimmin
This is horrendous. I read this piece about the Mosul Dam
([http://www.newyorker.com/magazine/2017/01/02/a-bigger-
proble...](http://www.newyorker.com/magazine/2017/01/02/a-bigger-problem-than-
isis)) a month or so back and found it very alarming, but wasn't sure how
seriously to take it. I'm taking it more seriously now.

~~~
sbarre
I thought about the same article when I read this.. It's a fascinating and
terrifying read..

------
thatswrong0
The erosion on the primary spillway is looking pretty nasty. Even if / after
they manage to keep the emergency spillway from collapsing, they will probably
need to continue running the primary spillway at a high flow rate to get the
reservoir down to safe levels to ready for future storm systems and the coming
snow melt, and this will continue to eat away at the hillside (they're
currently dropping lake levels by 4" (!!) an hour). That's a significant
outflow. It's a good thing that the spillways are decently far away from the
actual dam structure. But it sure is going to be one expensive cleanup
operation in the dry season..

Fingers crossed that things stay drier and cooler for the sake of all these
people

------
CaliforniaKarl
First, and importantly, my hopes go out to everyone that they are able to
evacuate safely, and that nothing bad happens.

I wonder, how do you test for something like this? I mean, you can certainly
plan, and I imagine that the emergency spillway was examined at the time it
was planned, but no plan survives contact with the enemy, and the best thing
to do is to test.

But, to test the emergency spillway you need to fill the dam to the point
where it's overflowing, and I believe it's been a few years since we've gotten
close to that. Certainly not any time in the last year.

Besides, if it was tested in the past, it may be that the drought conditions--
followed by all the rain--changed the soil in such a way as to enable this.

I need to make a note to read the report when it comes out; I'm sure it'll be
interesting.

~~~
k26dr
The emergency spillway has never been needed before, so it's never had a
chance to be tested by the looks of it

~~~
ChefDenominator
The rule for backups is that if you haven't successfully performed a complete
restoration from backup, then you have no backup.

Same principle seems to apply to spillways.

------
molecule
_> “Anytime you take on a situation like this where you seek to evacuate
thousands of people on very short notice, it can be a chaotic situation,”
Honea said. “We understand that.”_

 _> Sunday night gridlock as Marysville residents evacuate_

 _> After having to evacuate several times before, Agrifoglio said, she was
used it._

 _> She’s confident her husband will be able to evacuate if he needs to, but
Tommy would have to wait out a flood._

 _> Erin English of Linda said she got a robo-call a few minutes ago telling
her to evacuate and get to higher ground._

"The Wire: to evacuate":

[https://www.youtube.com/watch?v=h5d82ndui_s](https://www.youtube.com/watch?v=h5d82ndui_s)

------
kbutler
Having grown up in a town that I saw flooded when the Teton Dam failed
([http://www.history.com/topics/us-
states/idaho/videos/enginee...](http://www.history.com/topics/us-
states/idaho/videos/engineering-disasters-teton-dam)), I've been watching this
closely.

Thankfully, it appears the actual body of the dam is unlikely to fail, so
hopefully even if the emergency spillway fails, it won't be a catastrophic,
immediate draining of the whole lake.

------
jboggan
4 months of record snowpack still to melt. It will be summer before any
repairs can be seriously made.

~~~
jeffdavis
Why? Can't they patch cement under water?

~~~
kbutler
Underwater, yes.

Under a stream of water moving 65,000 CFS, ripping out chunks of solid cement,
probably not so much.

------
Gravityloss
Couldn't you just bring in a few oil / gas pipes (or whatever you happen to
have) and siphon it in a more controlled manner? The country doesn't seem to
have a problem in creating oil and gas piping networks quickly...

40 million cubic meters in 24 hours means just 15 2m diameter pipes running at
10 m/s.

I would imagine the same amount of water flowing over a longer period time
would cause less erosion even if the pipes wouldn't reach all the way down...

Edit: You could even do it with 6000 20 cm diameter pipes, probably plastic
would do.

~~~
giardini
Gravityloss says> "Couldn't you just bring in a few oil / gas pipes (or
whatever you happen to have) and siphon it in a more controlled manner? The
country doesn't seem to have a problem in creating oil and gas piping networks
quickly..."

Good idea, but this is happening in CA, where pipelines don't sprout so
quickly.

------
ruffrey
Following local news, it appears the greater Sacramento area should be OK even
with a catastrophic failure to the emergency spillway.

Between 130,000 and 180,000 people are being evacuated upstream.

------
nbanks
Is hydro more dangerous than nuclear? The Banqiao and Shimantan Dams killed
171k people, whereas Chernobyl killed 30 people directly plus an increase in
cancer risk. No one died directly at Fukushima, though zero to hundreds could
from radiation exposure depending on the estimates. About 18k died in the
tsunami.

(I just realized the Oroville Dam is for a reservoir rather than power
generation, but the risks are similar.)

------
blubb-fish
What was going on May 2016? Reservoir elevation at 891 feet.

[http://cdec.water.ca.gov/jspplot/jspPlotServlet.jsp?sensor_n...](http://cdec.water.ca.gov/jspplot/jspPlotServlet.jsp?sensor_no=1148&end=02%2F12%2F2017+23%3A31&geom=huge&interval=720&cookies=cdec01)

~~~
Amorymeltzer
Snowmelt. If you look even further back[1] you'll see that it's cyclical. Peak
runoff these days is usually March-April[2], so by May reservoirs should be
maxed out. The past few years have seen a major drought, so the curve can be
pretty dramatic.

1:
[http://cdec.water.ca.gov/jspplot/jspPlotServlet.jsp?sensor_n...](http://cdec.water.ca.gov/jspplot/jspPlotServlet.jsp?sensor_no=1148&end=02%2F12%2F2016+23%3A31&geom=huge&interval=720&cookies=cdec01)

2: [http://www.abc10.com/weather/sierra-snowmelt-peaking-
earlier...](http://www.abc10.com/weather/sierra-snowmelt-peaking-
earlier/187931002)

------
mrfusion
I wonder about the idea of running some large hoses /pipes temporarily to help
drain the water? Even a 3ft diameter would move a lot of water.

Or I also wonder if they could drill into the bottom of the Resavoir and let
the water drain into the ground?

~~~
maxerickson
You are thinking on the wrong scale.

The main spillway has been running at 100000 cubic feet per second. To carry
that in 3 foot pipes (7 square foot cross section), you'd need hundreds or
thousands of them (so a few just wouldn't do much of anything).

Same with trying to bypass the water to somewhere else. To make a difference
the bypass needs to be at a similar scale to the spillway, carrying tens of
thousands of cubic feet per second.

~~~
hvidgaard
The worlds largest pump, located in New Orleans, cost $500 million, cannot
move enough to match the spillway. You would need 5 of those to match the
flow. But realistically, a pump that can move 10.000 feet^3/s would greatly
reduce the stress on the rest of the pathways. Problem is, we cannot just rig
up a temporary pump with that capacity.

~~~
maxerickson
It's even a pumping station, with 11 pumps.

[http://www.mvn.usace.army.mil/Portals/56/docs/PAO/FactSheets...](http://www.mvn.usace.army.mil/Portals/56/docs/PAO/FactSheets/WCC.pdf)

Each can do 1740 cubic feet/second. And they are permanently installed and
basically don't have anything resembling pipes.

------
guard-of-terra
[https://www.youtube.com/watch?v=yhzKVdSnPmg](https://www.youtube.com/watch?v=yhzKVdSnPmg)

Live coverage.

They say situation is better now that drain is sufficient.

~~~
PuffinBlue
That stream has now ended, but you can still see the live webcam feed:

[https://www.youtube.com/watch?v=hSaAE6MbKE0](https://www.youtube.com/watch?v=hSaAE6MbKE0)

Not that you can see much as it's dark...

------
lisper
TIL the Oroville dam is the highest in the USA, 44 feet higher than the Hoover
dam. It's kinda mind boggling that it could actually fail tonight (though the
latest reports indicate that the situation is improving).

~~~
aji
to clarify: it's not the dam itself that's at risk of failure, but the
emergency spillway. while this scenario would be catastrophic, it's far less
catastrophic than the entire dam failing

~~~
ChuckMcM
Think about that statement, what does is mean to you that the "emergency
spillway failed" ? The ES is the portion of the dam that is slightly lower
than the overall height of the dam so that in the event the main spillway was
unable to release water fast enough, the water would start spilling here
rather than across the dam. If it "fails" then a portion of the dam ceases to
exist. That releases water through that hole uncontrollably. At which point
losing containment is generally a matter of when not if.

If it fails, it will be a double disaster, many people will lose property, and
California will lose some or all of the water in its largest reservoir. The
challenge is going to be keeping ahead of it through to the next storm.

~~~
khuey
The emergency spillway is around 30 feet high, the dam itself is 770 feet
high. The amount of water released from a failure of the emergency spillway
will be enormous, but still much smaller than the amount of water released by
a complete dam failure.

~~~
ChuckMcM
[http://www.sacbee.com/news/local/article132356269.html](http://www.sacbee.com/news/local/article132356269.html)
provides an excellent description of the challenge. The hillside where the
emergency spillway is would be at risk.

~~~
verytrivial
Excellent link, thanks. I found the following comment sobering:

"Countryman: It’s not going to be the (main) embankment failure, but it’s a
failure. If it does happen, there’s nothing saying that the ground is going to
stay where it is. That force of water will start tearing that hill apart​,​
and it could eat back into the reservoir and drain the reservoir."

------
lend000
How difficult would this really be to fix?

I imagine the most straightforward way to patch a hole, at least for a short
period, is to use the water pressure to your advantage and inject objects to
plug the hole from the dam side. Perhaps a thick metal plate lowered onto the
main breach, and then malleable plastics/rubbers to slow seepage around the
plate. Could probably push a hotfix out to master in a few days, for far less
than 100 million dollars.

Disclaimer: I haven't found any details on the design of the emergency
spillway and the suspected damage, so this is speculation.

~~~
jcranmer
Are you fixing it or are you making the inevitable failure even more
dangerous? The answer is not easily determined.

The current solution is to drain the reservoir of water as fast as possible--
this removes pressure on the hillside, and reduces the scope for damage should
the thing actually go.

As for actually patching it, the solution is dumping lots of grout. But that
only helps if the slope is actually stable and capable of supporting the
embankment and dam. If the slope is washing away, all of your patching is just
adding more weight to a structure that can't support its own weight anymore.

While looking at old examples of dam failures, I came across
[https://en.wikipedia.org/wiki/Sweetwater_Dam#1916_failure](https://en.wikipedia.org/wiki/Sweetwater_Dam#1916_failure)
... this seems awfully similar to what's happening at Oroville right now.

~~~
lend000
Of course it wouldn't be a permanent solution, but allowing the hole to exist
only makes it bigger in the short term.

Anyway, the Sweetwater Dam article led me to an entertaining read about
Charles Hatfield, the professional rainmaker:
[https://en.wikipedia.org/wiki/Charles_Hatfield](https://en.wikipedia.org/wiki/Charles_Hatfield)

Now this guy was a great salesman. It leads you to wonder if his apparently
high success ratio was a result of pure luck, if there's some truth to his
"evaporative mix," or as suggested in the article, he had great meteorological
prediction skills.

If weather patterns are not independent one year to the next, then just the
fact that only statistically significant drought-ridden cities call for his
help probably suggests that all of these cities are "due" for rain regardless.

