
Realtime Analysis of the Oroville Dam Disaster - rodionos
https://github.com/axibase/atsd-use-cases/blob/master/OrovilleDam/README.md
======
kolbe
I like what you're trying to accomplish, but you are missing a very helpful
piece of information in your analysis. I'm sure you noticed how poor of a
predictor rain fall is in your assessment of how much water will be added to
Lake Oroville. This is largely because Oroville is filled from Sierra Nevada
runoff. If a particular storm system is warm (as was the case with the latest
one), it will mostly rain in the Sierras. This has a twofold effect: one, the
precipitation doesn't stay put at higher elevations (as snow does), and two,
it melts the existing snow, causing it to also be added to the downstream
water accumulation. So a key part of forecasting is not only to look at
expected precipitation, but also the expected snow levels.

~~~
ransom1538
"I'm sure you noticed how poor of a predictor rain fall is in your assessment
of how much water will be added to Lake Oroville."

Having worked in hydrology (in forecasting) for a year out of college -- yeah
-- you might as well use tea leaves and Tarot cards. People can't even predict
weather. Let alone: Snowpack + weather.

~~~
234dd57d2c8dba
Genuine question here, if predicting the weather for a localized area such as
a small region Cali is "tea leaves and Tarot cards", why are we so confident
in the prediction of the climate for the entire planet?

~~~
js2
Q: If forecasts can’t get next week’s weather right, how can we trust
predictions for decades or centuries from now?

A: Weather and climate are not the same. Weather is individual, day-to-day
atmospheric events; climate is the statistical average of those events.
Weather is short-term and chaotic and is thus inherently unpredictable beyond
a few days. Climate is long-term average weather and is controlled by larger
forces, such as the composition of the atmosphere, and is thus more
predictable on longer timescales. For the same reasons, a cold winter in one
region does not disprove global warming.

As an analogy, while it is impossible to predict the age at which any
particular man will die, we can say with high confidence that the average age
of death for men in industrialized countries is about 75. The individual is
analogous to weather, whereas the statistical average is analogous to climate.

[https://www.climatecommunication.org/questions/predictions/](https://www.climatecommunication.org/questions/predictions/)

~~~
refurb
OK, I'm going to play devil's advocate. That answer doesn't really seem all
that good since it doesn't address the predictability at all.

To use the human lifespan argument, yes we can say the average lifespan for
men is 75, but that's _looking backwards_. How good would we be at predicting
future life expectancy? I'd say we're probably pretty bad at it.

Also, yes, we're trying to predict the average temperature of the earth with
climate models. However, that average is determined by the climate in a number
of different areas.

Someone please explain this to me.

~~~
Cogito
I'll take a stab :)

You ask "how good are we at predicting future life expectancy?"

Unfortunately I can't do an analysis right now, so hopefully this qualitative
discussion will help answer it for you.

If you look at historical life expectancy, grouped by cohort, you'll see a
relatively smooth function with easily identifiable trends. So, group
everybody into the year they were born, and graph their average lifespan.

Past trends do not guarantee future performance, however a smooth function
implies an underlying order to these observations. This is the core thesis
everything else stems from then; we assume there is a relationship between the
year someone was born, and their average lifespan.

Now a function relating _just_ the year they were born to their average
lifespan is almost certainly too simplistic. Where they were born, their
socioeconomic status, and so much more will affect that number. The problem we
have is that many of these parameters are hidden to us. Even worse, we can't
even say for sure what all the parameters are! What we can do, however, is
estimate the effect of these parameters, and even estimate the effect of
parameters we don't know exist.

This process is inherently fuzzy, as statistics and modelling from less than
perfect knowledge must be, but the models that have been created have proved
to have great predictive power. The existence and general profitability of the
life insurance industry is evidence to that.

We use models all the time, and for the most part this goes unquestioned.
Regardless of your model of the sun and planets, it better predict the sun
rising tomorrow, or else it's got some pretty big gaps. If someone told you
they predicted the sun would not rise tomorrow, you'd be rightfully
discredulous. But you'd be as equally discredulous if someone told you it was
impossible to predict the future, so we really don't know if the sun will come
up or not.

We test our models on their predictive power. Even if our models were bad, we
don't simply throw them away because they are not perfect. We work to refine
them and make them more accurate. Asimov's essay on the relativeness of
'wrong' is well worth the read.

So, life expectancy is a decent model, and is constantly being improved upon
as we learn more about the world. Something may come along and cause us all to
die, or live forever, but that remote possibility is no reason to throw our
hands in the air and say the whole exercise is pointless.

Similarly, our climate models may be inaccurate or not account for some
unknown future event, but that is not a reason to stop refining them, nor a
reason to say "we can't know the future so this is pointless."

~~~
refurb
I appreciate the response.

I understand that you can model something and constantly improve it, but that
still doesn't inspire confidence in the model's predictive ability.

Maybe a better answer would be: "Yes, weather forecasts are often wrong, but
climate modeling from 10 years ago accurately predicted today's global
temperatures with a margin of error of +/\- 0.5%."

~~~
jcoffland
Can you provide any evidence that "climate modeling from 10 years ago
accurately predicted today's global temperatures with a margin of error of
+/\- 0.5%." I don't believe that statement. Perhaps you were saying wouldn't
that be great proof if it were true.

~~~
refurb
I'm not claiming that's true, but if it were, it would be strong evidence that
the modeling is accurate.

------
stuckagain
Wow almost every statement here is wrong.

#1: the dam is managed in the winter about 1 million acre feet below the top,
for flood control purposes. The spillway has been operating all winter long.

#2: The operator cannot decide to use the emergency spillway. Water just goes
over it when it approaches the top of the dam.

#3: no water has gone over the dam. That would destroy it.

~~~
wyldfire
Why does water passing over the dam destroy the dam?

~~~
mintyfresh
In 1986, water flowed over the top of the Auburn Cofferdam and resulted in
complete failure of the dam. See this video of that incident [1] for an
example of how the overtopping of an earthen dam leads to failure.

[1]
[https://www.youtube.com/watch?v=tDmwo5nsWfQ](https://www.youtube.com/watch?v=tDmwo5nsWfQ)

~~~
LeoPanthera
This seems to show that it was the "spillway plug" that eroded and failed. I
don't know what a spillway plug is, but the narration seems to imply that it
is _designed_ to fail in emergency situations.

~~~
mintyfresh
In the beginning of the video, the narration talks about the spillway plug
being a feature designed to erode in a fashion that delayed/slowed the
inevitable failure of the entire dam. In this case, the spillway plug helped
the dam release water in a semi-controlled fashion over a series of hours,
instead of an uncontrolled fashion in a matter of minutes.

------
mturmon
Kind of a fun study, enabled by the presence of so much public-domain data
from CA DWR.

One piece that's missing from this analysis is upstream precipitation. You are
sensing precip at Oroville itself, but water in the dam comes from everywhere
upstream (3600 square miles according to [1]). As well as (potentially)
snowmelt.

People doing forecasting of reservoir levels will be integrating distributed
precipitation information, snowpack, and temperature, with a soil runoff and
routing model to get predictions.

[1]: [http://cdec.water.ca.gov/cgi-
progs/profile?s=ORO&type=dam](http://cdec.water.ca.gov/cgi-
progs/profile?s=ORO&type=dam)

~~~
stuckagain
Indeed. If we want to leave the analysis to professionals we would look at the
CDEC river guidance for the Feather above the dam. Here it is.

[http://cdec.water.ca.gov/guidance_plots/MFP_gp.html](http://cdec.water.ca.gov/guidance_plots/MFP_gp.html)

As you see the forecast flow is only about one third of that experienced on
Friday past.

~~~
mturmon
Thanks for locating that. I work with people who do retrospective runoff and
streamflow modeling (using past measurements to make better models), but not
the predictive stuff in the graphs you linked.

~~~
stuckagain
NOAA has nationwide river sensor and guidance data if you are interested in a
river near you.

[https://water.weather.gov/ahps/forecasts.php](https://water.weather.gov/ahps/forecasts.php)

------
harlanlewis
This is terrific. Would be a great resource for journalists to identify and
understand some of the key points that can then be shared in a more public-
friendly format. I wish all stories had this kind of accessible data “behind
the news” that could be explored!

Here's a great article on climate change's effects on our water infrastructure
in light of the Oroville Dam's situation:
[https://www.nytimes.com/2017/02/14/opinion/what-
californias-...](https://www.nytimes.com/2017/02/14/opinion/what-californias-
dam-crisis-says-about-the-changing-climate.html)

An example - the bulk of California's water storage is in the natural
reservoir of mountain snowpack. The large volume of precipitation this year,
much of it as high-altitude rain falling on snow, has caused an extraordinary
amount of snowmelt in a short period of time. The natural reservoir of
snowpack is rapidly released into our manmade resorvoirs and strains or
exceeds their capacity. This cycle of alternating extremes, drought to wet, is
expected to continue, and our water infrastructure's capabilities must be
planned in light of that.

------
seanp2k2
More analysis on the dam situation: [https://www.metabunk.org/oroville-dam-
spillway-failure.t8381...](https://www.metabunk.org/oroville-dam-spillway-
failure.t8381/)

~~~
chris_7
Is welding giant metal sheets over the hole an option?

~~~
karlkatzke
No. You would need to anchor the metal plates to something, which means you'd
need to drive spikes down into bedrock and then weld things to the spikes.

------
mxfh
Would it be feasible to dig out another minor temporary overspill or diversion
out of the basin into another one somewhere far away from the dam, and more
importantly the emergency spillway?

Dry Creek basin seems to have some points were it's just a few meters of a
hump over the emergency spillway level.

[https://ngmdb.usgs.gov/maps/topoview/viewer/#16/39.6744/-121...](https://ngmdb.usgs.gov/maps/topoview/viewer/#16/39.6744/-121.5609)

[https://opentopomap.org/#map=17/39.67423/-121.55954](https://opentopomap.org/#map=17/39.67423/-121.55954)

[https://opentopomap.org/#map=16/39.65270/-121.54263](https://opentopomap.org/#map=16/39.65270/-121.54263)

~~~
karlkatzke
It's unnecessary. The current emergency spillway is _already_ on the other
side of a hill made out of bedrock from the dam itself.

All of the concern about the 'failure' is a matter of loss of control of water
release, not of breach of the main dam structure.

~~~
mxfh
I thought the main danger, and reason for evacuation, was a potential
uncontrolled failure, due to headward erosion, of the emergency spillway dam
structure. (Thats the structure between the regular spillway and that parking
lot)

[https://twitter.com/TaberM_PE/status/831149440262164480](https://twitter.com/TaberM_PE/status/831149440262164480)

~~~
karlkatzke
Yes -- which would only result in the loss of control of the amount of water
above the level of the bottom of the spillway, or the bedrock under the
spillway. That's maybe the top 30 feet at the most.

While that's still a lot of acre feet, and it would create a 'wall of water'
situation in the first surge (hence the evacuation), it's not as significant
as the dam failing and the entire reservoir emptying through it.

------
caseyf7
This is a great analysis.

However, this seems a little off: "Based off of our estimate, for every inch
of rainfall at the Oroville dam, 136,790.5 acre-feet will be added to the
reservoir." The relationship probably isn't linear. Much less of the first
inch of rain makes it to the reservoir vs. the 5th inch of rain.

Hopefully, the next iteration will project how many inches of rain it will
take this weekend to top the spillway again.

~~~
AnimalMuppet
> Much less of the first inch of rain makes it to the reservoir vs. the 5th
> inch of rain.

Depends on whether the ground is already saturated.

~~~
pilom
Even if the ground is saturated, plants still will absorb more of the first
inch than the 5th.

~~~
AnimalMuppet
I don't think that's right. If the ground is saturated, the plants won't
absorb _any_ of it, because it won't sink into the ground at all, because the
ground is saturated.

(That is, unless you're talking about plants absorbing water from their leaves
directly, before the water hits the ground. I don't know that plants do that
when their roots already have plenty of water, but I also don't know that they
don't.)

------
clamprecht
Several pilots have published videos of overflying the Oroville Dam. Here's
one from a guy who makes some good videos:

[https://www.youtube.com/watch?v=q2YHGR3kVLk](https://www.youtube.com/watch?v=q2YHGR3kVLk)

The money shot is at 2:25

~~~
mabbo
That's a lot of boats up just past the dam. I'm surprised their owners aren't
hastily trying to get them out of the water. If the dam fails in a major way,
god only knows what will happen to the boats...

~~~
Stratoscope
No one is worried about the dam failing. The emergency spillway is the
problem. It's the hillside you see in the video with water flowing down it, to
the left of the main spillway.

If the emergency spillway failed, it could lower the water level in the
reservoir by 30 feet. That would be catastrophic downstream, of course, but
probably wouldn't have much effect on the boats.

~~~
mabbo
> No one is worried about the dam failing

My wife, a Water Resources Engineer, is. If the damage to the spillway starts
to move sideways, or uphill too far and too deep, you could see the main dam
get damaged. It's not as likely as the emergency spillway dropping things 30
feet, as you say, but it's still on the table as a worst-case scenario here.

~~~
Stratoscope
Oh my. I stand corrected.

Well, let's hope for everyone's sake that this worst-case scenario does not
happen!

------
NDizzle
Thanks for putting this together. Keep me in your thoughts, guys. There's a
lot of misinformation about what's going on up there. I'm in Yuba City, 2
miles away from the feather and 30 ft up.

They reduced the mandatory evacuation order but more and more emergency
personnel are arriving. There are (unfounded at the moment) local reports of
water seeping underneath the emergency spillway weir.

------
astrodust
As always, the quirky units Americans insist on using never cease to amaze.

Acre-feet. Of course.

The only thing missing here is nautical miles and football fields.

~~~
ojii
Football fields are area though, not volume. Maybe washington-monument-
football-fields for an easy and relatable unit?

~~~
astrodust
Then to make it more authentic, have other things like Liberty Statue College
Football Fields and Washington Monument NFL Fields.

------
ransom1538
Oroville dam feeds into the Feather river, the Folsom dam feeds into the
American river. Here is the kicker: both the American and Feather feed the
Sacramento river - a major bottle neck.

Folsom dam has turned on the spill at insane rates the past few days. I wish
people living in Sacramento county (my parents) would take things more
seriously.

[https://cdec.water.ca.gov/cgi-
progs/queryDaily?s=FOL&d=13-Fe...](https://cdec.water.ca.gov/cgi-
progs/queryDaily?s=FOL&d=13-Feb-2017+03:47&span=1month)

~~~
stuckagain
Sacramento will inevitably be destroyed without warning when an earthquake
strikes Folsom. Folsom dam is basically a trade where Sacramento gains
temporary flood relief in exchange for a certainty of being wiped out by the
instrument of that relief. There is a strong economic argument that this makes
good sense.

~~~
moocow01
Well first of all Folsom has little to no seismic activity nor does
Sacramento. If an earthquake hit Folsom hard enough to impact the dam Im
pretty sure the bay area would be eviscerated. But if the dam was to falter,
the water would actually just go into Lake Natoma and sit behind Nimbus dam
rather than turning Sacramento into a lake. Even if both dams failed fully or
partially, Sacramento levies would experience an increase in flow and volume.
You could presumably have a breach in the levies in one or more places but one
thing to know is that much of the levies that surround downtown Sacramento are
rated at 500 year partly due to the capitol being in Sacramento.

------
Symbiote
I realise this is done to show off the ATSD tool, but it would also make a
really good example using a Jupyter Notebook. GitHub will process and render
those itself.

Example:
[https://github.com/benlaken/Comment_BadruddinAslam2014/blob/...](https://github.com/benlaken/Comment_BadruddinAslam2014/blob/master/Monsoon_analysis.ipynb)

------
anigbrowl
It's great that you're building on this dataset but I'm not sure you're well-
placed to pronounce on it being a disaster. Database expertise doesn't make
you an expert on civil engineering.

------
alextheparrot
I really enjoy the graphs and analysis produced by this project, but does it
irk anyone else that the Y-axis does not start at 0 in all the graphs? There
are some graphs further down the page that start and 0 and they seem to show
the data so much better (Water is increasing, but not 50x or whatever).

------
chris_7
What ever happened to the Mosul dam? Stories from about a year ago made it
sound like collapse was imminent, but it hasn't happened yet. Did they do
repairs, or are they just unsure when it will happen?

~~~
yohoho22
The New Yorker did a Reporter at Large on it last month:
[http://www.newyorker.com/magazine/2017/01/02/a-bigger-
proble...](http://www.newyorker.com/magazine/2017/01/02/a-bigger-problem-than-
isis)

Sounds like many are still worried about it, but there's really no consensus.

------
Fiahil
It looks like someone had spend quite some time doing this on working hours.
It is to showcase something ("where is the ad?"), or someone asked and paid
for this analysis?

~~~
ebcode
The ad is in this sentence: "Additionally, this article illustrates how
publicly available data from the California DWR can be easily loaded into the
non-relational Axibase Time Series Database (ATSD) for interactive analysis
with graphical representation of open data published by government
organizations."

~~~
jimmcslim
The ad is also in the URL:

[https://github.com/axibase/atsd-use-cases](https://github.com/axibase/atsd-
use-cases) ...

Still, its a TSDB that I wasn't aware of, so it worked on me!

Actually a really practical way of showcasing a product without markitecture
brochureware. A GitHub repo and links to Docker images.

------
rismay
This is a very educated estimate. Let's hope it rains less than 2 inches per
day.

------
dkarapetyan
Will a lot of infrastructure survive the new weather patterns?

~~~
snarf21
No, we've done a very poor job of even keeping up with maintenance in this
country. Plus we've push the boundaries of building where we shouldn't. It
won't end well for a lot of people.

------
pm24601
"Disaster" ? not yet (and I hope not ever)

------
AnimalMuppet
_Please_ tell me Betteridge's Law of Headlines does not apply here...

~~~
Stratoscope
Does Betteridge's Law of Headlines Apply Here?

No. At least not strictly speaking.

The _dam_ is in no danger. The _spillways_ are the problem. The main spillway
is badly damaged, and the emergency spillway was in some danger of collapse on
Sunday.

The main spillway is a long straight concrete chute with a gate at the top to
regulate the flow. If the erosion in this spillway worked its way up to the
top, it could damage that gate and operators would lose the ability to control
the outflow.

The emergency spillway is a low concrete wall with a hillside below it. Its
top is lower than the dam top, so water will go over this wall (and did on
Sunday) instead overtopping the dam itself. The worry here is that erosion of
this hillside could cause the wall to collapse.

Both spillways are separated from the dam by a large hill. Even if they
failed, the dam would survive. So there wouldn't be a flood of all 700
vertical feet of the reservoir, but there could be a flood of 30 feet from the
emergency spillway.

Of course if you were in the path of that flood, the distinction between the
"dam" and the "spillway" would be small consolation.

The Metabunk page that seanp2k2 linked has some good information and
discussion:

[https://www.metabunk.org/oroville-dam-spillway-
failure.t8381...](https://www.metabunk.org/oroville-dam-spillway-
failure.t8381/)

And the YouTube video that clamprecht linked has a good view of the dam and
spillways on Sunday:

[https://www.youtube.com/watch?v=q2YHGR3kVLk&t=2m24s](https://www.youtube.com/watch?v=q2YHGR3kVLk&t=2m24s)

------
mathgenius
What is the point of all this data and analytics if the author does not even
speculate on an answer to the question that is being asked?

------
erikpukinskis
I never considered it, but maybe climate change will help clear some of our
waterways of harmful dams.

~~~
maxerickson
Bad news, significant flood control+reservoir dams will certainly be rebuilt.

So if you are rooting for big dams to be destroyed by weather, you are just
rooting for short term harm and suffering, there won't be any long term
changes to the river systems.

~~~
jessaustin
This certainty is unwarranted, in the recent political context.

~~~
maxerickson
Being utterly indifferent to thousands of lives being massively disrupted is
unwarranted in pretty much any context.

~~~
jessaustin
That's pretty fuckin' rich. With the possible exceptions of wars and nuclear-
plant meltdowns, nothing disrupts lives on the scale of large dams. I didn't
vote for the Orange One, but this is why he won.

~~~
maxerickson
If it helps, I'm not coastal or elite.

It's certainly a fair criticism of my phrasing, but having your home washed
away due to weather is quite different than being compensated to uproot.

