Oroville dam spillway expected to collapse

UPDATE: Drone video over spillway added.

Collapse of emergency spillway expected, evacuation ordered

oroville-spillway-fail

Department of Water Resources officials say they expect the emergency spillway at Oroville Dam to fail, and say residents should evacuate northward.

The emergency spillway suffered erosion and could fail, according to DWR. If that happens, the water behind that barrier will comedown the hill and down the river.

Flow through the broken main spillway was increased to 100,000 cubic feet per second in an effort to lower the water level in the lake more rapidly.

The Butte County Sheriff’s Office reports helicopters will be depositing rock-filled containers to strengthen the potential failure point.

Bud Englund, a public information officer for the incident, said downtown Oroville and low-lying areas, including residents along the Feather River from Oroville to Gridley, are being evacuated.

Reporter Andre Byik said Caltrans and the California Highway Patrol have converted the southbound lanes of Highway 70 into northbound lanes to expedite the evacuation. Traffic there is still nearly gridlocked.

An evacuation center has been set up at the Silver Dollar Fairgrounds in Chico. Black Butte Lake west of Orland has also opened up the Buckhorn Campground to evacuees.

Emergency operations centers as far south of Sacramento have been notified, Englund said.

Evacuation orders have also been made in Yuba and Sutter counties.

From ChicoER.com


My local newspaper publishes a scathing editorial of DWR idiocy and mismanagement

Live video here: https://www.facebook.com/KCRA3/videos/10155026580966514/


UPDATE: DWR issued this statement.n their track record so far…not sure its all that reassuring.

oroville-overflow

Earlier today, before erosion of the emergency spillway began

OROVILLE DAM, Calif. – The Department of Water Resources has provided an explanation as to why the mandatory immediate evacuations in Oroville and areas downstream are occurring. The concern is that erosion at the head of the emergency/auxiliary spillway issued evacuation orders for residents. The concern is that erosion at the head of the emergency spillway threatens to undermine the concrete weir and allow large, uncontrolled releases of water from Lake Oroville. Those potential flows could exceed the capacity of downstream channels.

To avert more erosion at the top of the emergency/auxiliary spillway, DWR doubled the flow down its main spillway from 55,000 cubic feet per second (CFS) to 100,000 cfs. The next several hours will be crucial in determining whether the concrete structure at the head of the auxiliary spillway remains intact and prevents larger, uncontrolled flows.

Current flows are contained with downstream channels.

Flow over the auxiliary spillway weir began Saturday morning and has slowed considerably. DWR officials expect that flow to stop entirely soon, according to a press release sent at 6:11 P.M. Sunday. This would reduce the erosion on the downstream side of the structure.

DWR officials stress that Oroville Dam itself is sound and is a separate structure from the emergency/auxiliary spillway.

Source: http://www.water.ca.gov/news/newsreleases/2017/021217-pm_release_oroville_evacuation.pdf

UPDATE: Live view from the State Emergency Operations Center

UPDATE: Drne video shot earlier today:

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Wim Röst
Phil B

Dear God. Do you think maybe next time there’s a drought in Cali they’ll use the opportunity to make the dams bigger and stronger rather than wringing their hands about how it’ll never rain or snow again?
When the water level drops, it’s time to start reinforcing/build higher because it’s only going to rise up again.

LamontT

Maybe just refurbish and do maintenance on things such as … … oh spillways.

R. Shearer

Apparently, they were banking on the permanent drought lasting a little longer.

Peter Miller

Phil, that’s far too obvious for those of us who live in the real world. If you ‘think’ like a greenie, your negligence and stupidity will not be your fault, but that of climate change, global warming, Donald Trump or whatever.

Janice Moore

+1

RockyRoad

“Climate Change”, especially the variety taught in California, create such a brainwashed following they have no clue what needs to be done.
For ample evidence, just consider the type of leaders those idiots in California have elected–they also have no idea what needs to be done or when.
Maybe once they see a huge swath of their state washed away, they’ll come to the realization that CO2 doesn’t equal climate. But by taking that irrational position they now believe a drought is normal and continuous.
I saw the destruction that resulted from the Teton Dam failure and it was massive. Plus, the reservoir drained by that failure was much smaller than the Oroville reservoir.
Heaven help California.

WR

Sorry, there’s no money for things like that. We have to pay for illegal immigrants to get free tuition, for inmate sex change operations, Eric Holder’s consulting services on how to undermine the federal gov’t, Climate change awareness programs, etc. But don’t worry, there will be yet another emergency one time tax increase proposition that will pass with 70% support, that somehow turns into a permanent tax increase, followed by yet another proposed tax increase, rinse and repeat.

Johann Wundersamer

La-La-Land

Johann Wundersamer

Climate change models running on super computers. Karl et.al. will fake data bust the flood pause away.

Mike Bromley the wannabe Kurd

They should have heaped riprap on the downstream side of the alt-spillway as a dispersant of fluvial energy. But no, they waited for the dang thing to fill all the way up. A riprap pile with its interstices filled with smaller cobbles would have (Not “Could” have) dispersed the erosive power of the overtop with a minimum of expenditure. I’m not sure why they clearcut the hillside below…I guess to prevent the influx of floating debris into the Weir Diversion downstream? Vegetation would act as a deterrent to erosion….wouldn’t it?

Tim

And the rest of the country has to pay for arrogance and need for an over populated state that thinks they know everything
Hope the republicans get out before it breaks the rest hope they can swim

These permanent droughts are not what they used to be.

george e. smith

Well just wait till the snow thaw starts, and then watch them scramble. There is NO way to get water out of lake Oroville fast enough to handle the coming snow melt, and if the lake was already empty, it will still probably fill to overflowing.
Can you see in the video just HOW HIGH the lake rim is ABOVE the regular spillway, which now has NO WAY to release water fast enough.
If you build it high, the resulting flood will just be that much worse.
G
Those trucks parked on there (four of them) is probably what cracked the paper thin cement floor whenever that was taken, and the bottom has been busted ever since, because that’s exactly where the hole is, and as you can see through the hole, there is absolutely nothing underneath supporting that concrete and chicken wire flimsy skin. The hole is exactly where the damage was that they were looking at back whenever those trucks were parked there.

I recall a flood in Australia not too many years ago, attributed to AGW faithful never imagining a Climate Disruption Drought might end on it’s own, so they left the reservoirs over filled before the deluge started. They consistently fail too understand that things tend to even out; too dry one season means too wet in another.

Bryan A

They simply didn’t learn the lesson taught by the story of Joseph and the Pharaohs. Joseph instructed the Pharaoh that the dream meant 7 years of abundance will be followed by 7 years of famine and to stockpile ½ of the food produced during the abundant times to get through the lean years.
California should have followed the example and updated water resource infrastructure during the Drought influenced lean times to prepare for the El Nino influenced abundant times.
After all, The Climate is never in a steady state

AP

George those people in the four trucks were inspecting seepage through the spillway. This is what would have caused the failure. Seepage resulting in piping failure beneath the concrete.

I’m sure all you Monday morning QB’s have been begging to have your tax dollars spent on infrastructure for years, right?

I wrote the following last Friday – “probably an erosion problem – to be safe, better look for more…” – this still looks correct.
Control of erosion at Oroville dam is the key task, until the situation is stabilized – then implement a longer term solution (better spillways?).
My Masters’ thesis described case studies of large mine slope failures (millions of cubic metres) and how we controlled them. We stabilized some large failures, and in other cases safely evacuated personnel when failure was inevitable.
The big difference is that all of my thesis cases were deep-seated failures and none were water-retaining structures. It was possible to stabilize some slides through the placement of large toe berms. In other cases, when the failure was not controllable, the slide was slow and was safely managed.
It is a very different situation when a water retaining structure is involved. Later in my career, we did place a toe berm to stabilize a large dam, after early movement was detected. In our case, there was zero overflow.
Oroville dam to date is apparently a shallow erosion problem, not a deep-seated failure. Normally we monitor the micro-movements of large dam structures to check for deep-seated movements. This can be done remotely, once the instrumentation is in place. Is this being done?
Regards, Allan
https://wattsupwiththat.com/2017/02/09/ororville-dam-spillway-collapse-may-be-due-to-missing-rebar/#comment-2422063
Allan M.R. MacRae wrote on February 10, 2017 at 3:20 am
Lindsay – Yup – probably an erosion problem – to be safe, better look for more…
Regards, Allan M. Eng. (Geotech.)

Wayne Eskridge

Might just be my system but your new post message comes in my outlook at about a 200 point font see below

Tom Halla

I wonder how the rest of the reservoirs in the Sacramento watershed are doing.

Macusn

they are full.
mac

Macusn

My aunt is near Carmichael and she said the Fulsom dam is outputting high levels and the river there is around 60 feet wider then normal.
mac

philincalifornia

Yeah, here’s Folsom, and how they’ve been letting the water out:
https://cdec.water.ca.gov/cdecapp/resapp/resDetailOrig.action?resid=FOL

James H

you can see the CA resv., here. http://cdec.water.ca.gov/cdecapp/resapp/getResGraphsMain.action.
Shasta is now 96% full. the others are close to 90%.
Oroville hourly data is here, http://cdec.water.ca.gov/cgi-progs/queryF?s=oro

tadchem

Engineering, especially Civil Engineering, requires compromises. Safety margins are expensive, and the need for a particular margin is unpredictable. Engineering a 1 sigma margin is much less expensive than a 2 sigma margin, but the lower the margin or safety the more likely an eventual failure may destroy the system. Standard industrial practice now recommends a 6 Sigma design to reduce failure chances to 1 in a million, but on a civil engineering project a 6 sigma reliability is prohibitively expensive.

David L. Hagen

DNR IGNORED 1996 FLOOD FLOW WARNINGS
Why mandatory 50% solar/wind by 2030 for unmeasureable reduction in “climate change” by 2300 –
BUT no planning to natural weather extremes?.
Natural and Human Factors in Recent Central Valley Floods, ROXANE FRIDIRICI

Widespread and destructive flooding occurred in 1986 and 1997 along rivers flowing into California’s Central Valley . . .
On December 26, 1996, the U.S. Bureau of Reclamation started releasing water at Folsom Dam on the American River. Maximum outflow peaked at 115,000 cfs, the channels’ design capacity, on January
2. The heaviest precipitation fell over the Feather River Basin, rather than the American River Basin, and this proved to be an important factor in Folsom Dam releases remaining below channel capacities (CLAC 1997). The brunt of the storm dropped approximately 15 inches of rain in the Oroville area. The DWR warned that releases from Lake Oroville could exceed channel capacity, threatening major downstream flooding. Inflow peaked at 277,000 cfs on January 1. Peak outflow was maintained at 160,000 cfs, utilizing maximum storage, but avoiding uncontrolled spillway releases that would flood downstream communities.

Did that 160000 cfs outflow cause the damage we now see?
Why no preparation for the full 277,000 including over the emergency overflow????

Scott

Because Governor MOONBEAM said it’d never ever rain in California ever again!….

Please don’t cloud the issue with facts…

Models predict up to 6C of warming…

catweazle666

“Models predict up to 6C of warming…”
OH, FFS!
Mosher, your computer games models – unlike REAL models used in engineering – aren’t worth a cup of warm spit.
It’s because of a’holes like Moonbeam taking notice of jumped-up amateur scientists like you and your NOAA buddies with your silly computer games producing utter BS like predicting AGW and endless droughts and using it as an excuse for all sorts of phantasmagorical buffoonery like spending all the taxpayer’s money on virtue signalling idiocy like transgender toilet signage to make themselves feel good that bad stuff like this takes place.
Go and take up a less pernicious hobby like stamp collecting , why don’t you?

Greg

Indeed, I saw on one of video press conferences that they had previously let 160,000 cfs through the regular spillway, yet now they are only letting 56000 cfs . WHY?
Yesterday I saw another where they said they are not using the hydro-generator to add extra outflow due to some technical problem and apparently it was not designed to be able to allow water through without the generator working.
Now someone downstream needs to ask if this lack of attention and funding is due to the fact that hydro is NOT classed as “renewable” in the US and thus is not benefiting from high tariffs paid of other renewable power.
Best get out of the other side of this situation first but serious questions need to be asked about lack of maintenance at the dam and how this relates to the stupid policy which pretends that hydro is not renewable energy.

AndyG55

“Models predict up to 6C of warming…”
roflmao..
You have got to stop paying those male escorts, Mosh.
Unless you are trying to sell them a used car.

MattN

“Models predict up to 6C of warming…”
So say the people that faked data to remove a 20 year pause.
Get that crap outta here…

Bartemis

Seriously, Steven Mosher, get a grip. This is not a flight of fancy. This is a real, catastrophic failure. Your people’s delusions have resulted in genuine harm. How much more will we have to endure before you wake from your stupor?

Bryan A

The Governor chose to listen to his Pharaohesq soothsayers (ala Michael Mann et. al.) who whisper in his ear things like “this is the new normal state” and “California will be in perpetual drought” rather than take advantage of the lean time to make much needed repairs to the states water storage system infrastructure.

David L. Hagen

Oroville Dam Design Considerations
ADJUSTING WATER RESOURCES MANAGEMENT TO CLIMATE CHANGE WILLIAM E. RIEBSAME Climatic Change 13 (1988) 69-97.

Changes now being considered for Oroville’s flood storage rules provide a striking contrast to adjustments at Folsom. The 1986 flood showed that Oroville dam was more than adequate to handle design floods. To increase their supply capacity, SWP managers have asked the Corps of Engineers to allow more rapid fill of the flood reservation in the spring to increase the probability of reaching full reservoir capacity each year.

Were these changes made to increase the supply capacity???

philip horner

To fully address the historical max flow they needed a spillway that would handle 330000 cfs. The broken spillway was rated for 150000cfs. So they probably needed two spillways all along. The emergency spillway is just a bathtub ring that will erode it’s downhill surface the more it is used and that is what prompted today’s evacuation of 160000+ people.

Retired Kit P

Only 6 sigma? Nuke plants, including safety related civil structures are designed to higher standards.

george e. smith

I hope to shout; safety margins are expensive.
Look what happens when you have NO safety margins.
This whole concrete skin was sitting on nothing more substantial that dirt blowing around in the wind.
All that the rebar did to this structure was to increase its weight to ensure that it would crack.
Take a King size bed sheet, and squeegee all over it about a mm thick layer of pancake mix.
Leave it to dry out, and then set the whole sheet reinforced pancake up on four chairs, one at each corner of the sheet.
There you have a model of what the Oroville Spillway is.
And after you admire your cheffmanship; why not invite the neighborhood kids over to use it as a trampoline,
g

awreet

Love this example

sciguy54

Looks like the damaged concrete spillway can flow about 5x-8x the max flow overtopping the emergency spillway.
If the emergency spillway causes the dam to fail, then it will be fairly obvious that the disaster would be the result of the hours operators spent standing in the closed concrete spillway wringing their hands and staring at their navels, and subsequently operating that system at partial capacity. Lack of maintenance combined with poor management and control.

Greg

Poor management certainly. But it is unclear if they had any better options last week.

AndyG55

I see another couple of possible issues.comment image

sciguy54

It looks like the DWR came within a gnat’s a** of killing 100,000 or so folks last night. And the dam is not safe yet. A wall of water is serious business. The state needs to shelve a few multi-billion dollar “fun” projects and take care of the basics for a few years.
There is apparently very little elevation delta between the top of the concrete portion of the emergency spillway and the mostly earthen portion out toward the parking lot. If water gets a bit too high (and it did) then erosion begins immediately out near the parking area. That whole area past the concrete structure will require a means to prevent subsoil water migration (sheet piling), and the elevation increased 5 or 6 feet at least. As was mentioned earlier, the concrete portion will require an extended concrete skirt on grade downstream and a wedge of boulders and smaller stones backfilled against the concrete emergency spillway so as to reduce the energy of the outflow. Then fix the da** main spillway and improve the generation system so it can be used during high water conditions.
If that is not too much to ask before you kill a few hundred thousand folks, DWR.

The washout gully directly under your arrow and VERY near the base of the concrete is what has my concern. To me, that is the critical weakness that could cause a catastrophic release of water.

cirby

The good part is that the erosion is supposedly slowing for now, after they opened the main spillway back up to full volume. Unfortunately, that means the main spillway is going to fall apart even faster.
The bad part is that, even if they manage to stabilize it for now, the next storm hits on Wednesday – and is supposed to dump four or five inches of rain on the area over the next few days.

I live in the mountains to the west across the valley. Here is the 10 day forecast which calls for almost 7 days of rain/snow staring Wednesday. …http://www.intellicast.com/Local/Weather.aspx?location=USCA0307

Bartemis

A perfect storm. Aye yi yi.

DC

I stand corrected by the facts. Failure of the Oro Dam emergency structure will no longer surprise me. I hope everyone gets out safely.

lance

Unfortunately, they will blame ‘climate’ change and or Trump, or both!

brians356

Isn’t Orville Dam a “flood control” dam? Ironic.

Ozwitch

Well, if it is, they should have lowered any water level above 100% within short order, like a day or two, that is what flood mitigation dams ought to do. But I’m amazed mostly about the poor quality of the spillway itself.

Chris 4692

No.

Yes, in part …

Javert Chip

The CA state website defines it as both.
Link: https://www.parks.ca.gov/?page_id=462

Paul Westhaver

I hope no people get hurt.

Janice Moore

Me too.

S. Geiger

Live news feed.

Stay safe Anthony, hope this subsides without major damage.

Rogerdownunder

As the young woman says, a fluid situation in deed….
Super serious and hope no folks get hurt but really …… the media at times
Also note elsewhere they’re dropping rock to reinforce the overflow – wonder if they’re trying to slow the erosion at the spillway failure too?

David L. Hagen

Failure to Prepare: Was this due to a “Permanent Drought” Global Warming Mentality?
Why no systematic evaluation of all possible failures over all possible natural weather systems?
Why no modeling of the emergency spillway overflow? Is not California home to Silicon Valley and modeling?
Why no testing of the emergency spillway overflow?
Consider the catastrophic consequences of communist China’s central planning and its coverup:
The Forgotten Legacy of the Banqiao Dam Collapse

In 1975, after a period of rapid dam development, a perfect storm of factors came together to topple Henan Province’s Banqiao Dam and kill an estimated 171,000 people. Today, on the cusp of another dam-building binge, some worry that factors which led to Banqiao’s collapse are re-emerging.

Will we suffer such consequences from today’s lemming drive to towards centrally planned mitigation of “climate change”? (aka “catastrophic majority anthropogenic global warming”).
Rather than the most cost effective and prudent adaptation?
Demand thorough verified and validated climate models with a thorough exhaustive evaluation of ALL factors, especially the still very little known natural weather variations!
NASA era Apollo scientists and engineers were forbidden from using unvalidated models.
Such engineers formed The Right Climate Stuff
They prepared a validated model for political planning. See:
Executive Summary, Bounding GHG Climate Sensitivity for use in Regulatory Decisions February 2014
Bounding GHG Climate Sensitivity for use in Regulatory Decisions February 2014
Don’t accept platitudes and excuses until it is too late!

+10

re: “Why no testing of the emergency spillway overflow?”
Impractical, until now …

David L. Hagen

Where there is a will there is a way!

“while the six turbines combined utilize a flow of 16,950 cubic feet per second (480 m3/s) at maximum generation.[43”

Any engineer could easily see that all you have to do is stop the flow through the hydropower and stop normal spillway flow. That would cause the river inflow to eventually flow over the emergency outflow. Politics overriding prudence. Ref: “Section 2: Proposed Action and Alternatives”. Federal Energy Regulatory Commission Final Environmental Impact Statement for the Oroville Facilities Project. Butte County, California. pp. 13–42. Retrieved April 2, 2012.

David L. Hagen

Climate Persistence extremes about 200% of Conventional statistics
Conventional “Markov” statistics very strongly UNDERESTIMATE long term fluctuations known as “Hurst Kolmogorov dynamics” by about a factor of 2 or more. See:
Hurst-Kolmogorov dynamics and uncertainty, Demetris Koutsoyiannis
Much of the current panic over “extreme weather” due to “climate change” is but unrecognized climate persistence or realistic variations in weather.
See further presentations and papers on Hurst Kolmogorov dynamics

tgmccoy

Saw at several different news sources Gov. Brown is saying:” HEELPP!!
Me sorry,,,reallly sorry….”
and…http://www.krcrtv.com/news/local/butte/emergency-spillway-unecessary-for-now-2013-photo-of-damage-surfaces-supervisor-blames-dwr/325934917
About ”deferred maintenance” on the dam…
Now about that choo-choo to nowhere…

Janice Moore

(cough) Did you say, tgm, that Jerry-Resist-the-Rest-of-America- Brown is calling for help?
lol.
President Trump: Hello?
Brown: Help! Help!
Trump: I think you have the wrong number. This is the number for the United States of America. Call your own federal government.
Brown: aaaaaaaaaaaaaaaaaaa
Trump: Yeah, that sounds about right. CAaaa — naaaaa– daaaaaaaa, specifically, Quebec. Your little climate buddies. Bye now! *click*
Brown: Hello? Silicon Valley? Can you, like, crank up the windpower? ….. Yes!!!!! NOW!!! Turn the velospaters, the jammerind-thingies that… oh, you know! like the propeller on a boat! Just AIM THEM ALL AT OROVILLE. We can BLOW this water with windpower. We’ll show the world that California LEADS THE WORLD!!!! ……. Hello?………………Hello???………………………… Hm. {hangs up phone} NOW who do I call
Mexico: Hello?
Brown: Hola, amigoy! Hey, I mean hoy. Hoive, HAVE, I got a deal for you, hambray ….

Richard G

The irony of this moment is epic but it’s just another example of how citizens are harmed by incompetent politicians.

Janice Moore

Indeed, Richard G. And, of course, that dialogue above was fun (and, sadly, reflects reality), we pro-free markets, private property, and personal liberty Americans will not turn a deaf ear to California (over 66% of whom do NOT support sanctuary anything or defying the IRS, etc.).
The actual dialogue would run parallel to this:
2AM
Dad: Hello?
Son: Dad, ……… I, uh, I need a ride home.
Dad: Things gettin’ kinda of wild over there at Grandma and Grandpa’s?
Son: Dad. I don’ feelverygoo…. Ifeel…… kinuh sick. Jus’ come, okay? I’m at……… the Chevron stashun in Orofille.
Dad: So. You went to that party even though we told you not to, didn’t you. Get your “really, really, good friend” Jerry to give you a ride home.
Son: Jerry jus’ drovinnoo the swamp.
Dad: (heavy sigh) Okay. I’m on my way. I’m just glad you’re alright. *click* {mutter, mutter, growl} I told him and TOLD him that Jerry was no good. Would he listen? NoooOOOOoo. “Jerry’s my best friend. If he says it’s cool then –” ………….. aaaa, whatever. This is what family is for. {starts his Chevy truck and backs out of the driveway}

Janice Moore

And of course there will be consequences. Dad and Mom will make a condition of living in their home, “No more participating in Jerry’s schemes, such as helping criminals hide inside the church and letting the air out of the tires of IRS official vehicles and taking money from Maria the nurse and Joe the plumber to fund Big Wind and Loudmouth Solar, Inc., etc., etc..”

RAH

Your really couldn’t make this stuff up! Brown begging for help from “the Nazi” after his states politicians have led the way in bombastic statements in defiance of the Trump administration enforcing Federal Law and the violence at Berzerkly!
Should conditions for aid be attached? They won’t be of course but it’s kind of nice to think about it.

MarkG

“They won’t be of course but it’s kind of nice to think about it.”
I wouldn’t bet on that. Trump is an expert at making deals, after all.

george e. smith

No Janice you have it all rong.
We Californians are wishing to secede from the USA. We are far too embarrassed to even associate with people as smart as Americans. But Jerry Brown and Joan Baez will still be able to make pretty music, even after Oroville dam fails.
Ooops !
I forgot; it already has failed.
g

As the primary spillway continues to deteriorate, especially now that re-upped the outflow to ease pressure on the emergency spillway, the erosion near the base is slowly working its way towards the dam….
There also is a HUGE wall above it that does not look like solid rock. If this wall collapses I hope it does not compromise the integrity of the dam.
I was waiting for someone to ask about this at the multi-agency press conference but no one did.

Sandyb

A cutback is occurring and will eat its way back until it reaches …….. same thing with the emergency spillway. Both spillways will cut back and start to eat away at that corner of the dam itself. I hope I am wrong.

Greg Cavanagh

I find it amazing that so many American bridges, roads, and now dams collapse. You guys must have a very low standard for construction. (And for me, I am a civil designer in Australia).

ironargonaut

That’s because we have more than two of them. 🙂 And by the way the dam is not failing or expected to. A lot of water may go down stream but not the whole reservoir.

Leo Smith

No, but they have an awful lot of dams and bridges

MarkW

Not just more, but I suspect the average age of such projects is greater in the US as well.

Usexpat

Greg, Not so much. I live in both countries and they both have similar standards as well as similar dickheads in government and both have “socially concerned citizens”. The US has it’s issues but I’ve often though governing OZ to similar to herding cats.

MarkW

Greg, I remember reading about a dam collapsing in Australia not too many years back. And for pretty much the same reason.

brc

This is reminiscent of the total failure of government agencies in Brisbane, Australia in 2011. After a long drought, the government of the day had bought into the hype that climate change meant the drought would be permanent. They spent $1 billion on a desalination plant and tried to implement permanent water restrictions. When the (forecasted) monsoon rains started to fall, and heavily, the government sat on its hands and let the main flood mitigation dam fill up over 100% – valuing the water for this economic value instead of operating the dam to the flood manual. The dam is supposed to even out flow down the river and prevent flooding. But they let it buid up wanting to hang onto the water. Eventually, fearing an overtop, they let the main floodgates open and intentionally flooded the 3rd largest city /urban area in Australia. https://en.m.wikipedia.org/wiki/2010–11_Queensland_floods#Brisbane_River_catchment
The current idiocy in Australia is that major cities are suffering from brown outs and blackouts because of the demolition of coal fired power stations. The same politicians who congratulated themselves on destroying the power generation capability and now searching for the guilty parties as seasonal summer heat dominates the eastern states and the population reaches for their air conditioners.
Until dams and power stations are returned to engineers and not social policy this will be an increasing trend. And the public stands by frustrated wondering when will the idiocy stop. Young people are being brought up thinking that dams fail and power stops – just the way it is and nothing can be done. Until they start experiencing what it is like to be at mercy of the elements the message is not getting through.

MarkG

The only thing Big Government has really proven to be good at is making really bad decisions.

Retired Kit P

So ‘little’ goverment does not make bad decisions?
Good and bad comes in all sizes.

Kalifornia Kook

Yeah, Little Government screws up, too. Hard to forget how Katrina made the lack of maintenance of the flood walls. That was due to similar needs to divert money from infrastructure to politicians pockets, er, I mean new useless projects (windmills, bullet trains, solar plants).

MarkW

When little governments make bad decisions, they don’t hurt too many people.
That’s the big difference.

What a sad state of affairs.

Ross

brc
You are correct. The error with the Wivenhoe Dam management was not to let the extra water go earlier enough, so the discharge could be controlled. It appears the same thing has happened here. ( Ironically this dam / lake is about the same size as the Wivenhoe)
I hope those responsible for any other dams in California and elsewhere wake up start discharging water a lot earlier.

Felflames

It didn’t help that the Greens held up any construction of other dams nearby that could have helped aver the disaster.
The Greens have blood on their hands in my opinion,and should be treated as the murderous scum they are.

ozspeaksup

yup
in the driest continent we have utter sh*t for brains greentards blocking dams
they need to have to live IN the areas they deprive

G. Karst

blc – you nailed it. Dams must NEVER be overtopped. Early release of water is paramount. Drought mentality prevented “wasting” water by spilling it. It may be unrecoverable now if there is actual overtopping of the e-spill. Time and flow rate overtopping e-spill will determine time to failure. Humans willingly gave control of the dam to nature. GK

Janice Moore

From above-cited Chico newspaper article:

The DWR can argue all day that this was an unforeseen and unpreventable act of nature ….

(http://www.chicoer.com/opinion/20170211/editorial-oroville-dam-crisis-a-failure-on-many-levels )
No, they can’t. They cannot argue that this scenario was not “reasonably foreseeable at the time the dam was built.” Now, if Mt. Shasta exploded like Mt. St. Helens did in 1980, that event would excuse the state from liability in Negligence. This rain event was well within the possibilities which would be foreseen by a reasonably prudent dam builder (here, the State of California is the “dam builder” — the engineers they hired, who no doubt told the state all the relevant facts, are not to blame (unless they lied which I seriously doubt)).
In short, such a scenario was well within the contemplation of the Defendant (as the State of CA most certainly will be if anyone suffers an injury who wants to be made whole) at the time the dam was made.
I do not fault the managers of the dam. They do their best within parameters/budgets set by –> Sacramento.
*****************************
May God come to your aid, dear Oroville area residents.
Praying for you,
Janice

Janice Moore

Further: The State of CA also cannot argue out of following a reasonably prudent maintenance/repair/water-release regimen.

Retired Kit P

Janice
“Mt. Shasta exploded like Mt. St. Helens did in 1980”
How often to expect that to happen? There are design criteria for such evaluations.
I have anti-nuke friends who moved up from Cali and bought a house on debris from the last major Mt Rainier eruption nut worry about the nuke plant 200 miles up wind on the other side of the mountains. Clueless.
We just bought property in a tsunami evacuation zone.
It is a dangerous world. I have no expectation that goverment will protect me from all risk. Practice a fire drill today. Be responsible for yourself and your family.

MarkW

Which is why she used it as an example of a rare and extreme event.

Steve Fraser

Moi, aussi.

Chris4692

No, they can’t. They cannot argue that this scenario was not “reasonably foreseeable at the time the dam was built.”

How do you know that? The dam was constructed in 1961. Which means that it was designed in the 1950s. The first nation wide Tech Paper covering precipitation frequencies was published in 1961, based on an analysis of data in the 30 years up to 1950. The statistical techniques used to do the analyses were developed in the 1940s.
In the 1950s the technology did not exist to predict the effects of a particular rainstorm on a watershed.
The dam was most likely designed according to estimates of flows based on the largest flood that the drainage area had experienced, and not according to any particular precipitation event.

yarpos

Expect lots of PR spin and the phrase “perfect storm of events” to be used frequently

Allencic

Who cares about the dam or the lake or the flooding? We’re going to have a bullet train from nowhere to nowhere. How in the name of God has California been dumb enough to elect an environmental imbecile like Moonbeam Jerry Brown the ignorant and incompetent as governor?

RockyRoad

Considering the mentality of California voters and their obsession with things illogical (climate change being at the top of the list), it isn’t surprising this has happened.
Trump should hold a workshop on responsibility and require that all Democrat governors attend; Republican governors need no such invitation because they’re responsible and will show (if nothing more than to demonstrate their bona fides.

Stpidpeople

Lol

Kalifornia Kook

Oh, but we love Moonbeam! We’ll elect him and all the other psychotics that want to run on the platform of ‘No growth – except for illegals’, castles in the sky (bullet trains, windmills), and make-believe (Hollywood). We do not reason, we emote. If you are capable of rational thought, return to wherever you came from. If you can only emote, you are welcome.
Now, let me return to my eternal spring dancing!

george e. smith

Well Jerry has had most of four terms as governor; two legal ones, and two illegal ones, to fix some of the infra-structure, and so far hasn’t accomplished much of anything.
Well Ivanpah was built on his watch I guess; that’s a success as a bird evaporator.
G

Mike the Morlock

A very good comparison is the the photo Steve placed on the other Orville dam article. examine the road that passes in front of both spillways. In places the road is gone and much of the ground between the road and the spillway.
reference to Steve’s photo
Steve Oregon February 11, 2017 at 12:31 pm
michael

Janice Moore
Janice Moore

comment image

Mike the Morlock

Janice Moore February 12, 2017 at 7:59 pm
I did not what to steal his thunder.
The erosion in just a day and a half is a shock. I think they know this would happen.
Nothing but bad choice due to the State government squandering time and resource.
So where is Governor Brown? A chunk of the state could be flooded in a few hours. Thousands of people are spending the night away from home where has he been during all this?
Then again do we care?
michael

Steve Oregon

Lake Oroville is quite large.
It covers 25 sq miles
Looking at the video, the right side of the E spillway is already eroded at the base.
That can only get worse.
The E spillway is 1700 ft long and judging by the video with people standing on the top to the right it is at least 60 ft tall.
It is going to collapse and 60 feet of the depth of the lake will spill into the land below.
I have very bad feeling that officials are way behind the curve and should be evacuating a much bigger area much quicker.
Or not?

Mike the Morlock

Steve
Please add the photo from you posted earlier, it is good reference.
michael

Mike the Morlock

from your earlier post,,,,

Richard G

I estimate the top 30 ft. of lake level is 450,000 AF. The top 50 ft. is about 750,000 AF.

Chris Nelli

I read the spillway is 30 ft high.

Steve Oregon

That must be on the inside? Look at that photo. Seems accurate.

The spillway is over 50 feet high.

Mike Borgelt

Looks like a replay of Brisbane Wivenhoe Dam 2011. I’m told Sacramento is under threat is that right?

troe

By increasing the flow down the damaged main spillway they have minimized water flowing over the auxiliary spillway. If they can keep that up they may be able to lower the lake level sufficiently before it rains again midweek. That seems to be the strategy. Hopefully it works.
Also hopefully the end of a drought which is a regular event in California will lead to questioning of their political leaders. Those who sound so convinced when they claim to understand weather and climate. Fact is they are simply speculating with great earnestness. But still speculating.

Jeff C

Thanks God things are looking better as the lake level continues to drop. Any takers on how many people get fired over this fiasco? I’ll take zero.
It was pretty clear what these DWR jackasses were up to yesterday when in Orwellian-like fashion they started referring to the emergency spillway the “auxiliary” spillway. It’s for an emergency, the fact it has never been used in 50 years and completely unlined makes that plainly evident.
Yet calling its real name might give Joe Six-pack the completely accurate impression that these geniuses didn’t know what they were doing (and hadn’t done their planning and maintenance jobs for at least the last five years). Rather than letting the public understand the gravity of the situation and prepare accordingly, they started their “nothing to see here” routine. It’s now a euphemistically-named “auxiliary” spillway (no emergency for heaven’s sake) just the routine use of an alternate, no big deal.
They deliberately mislead the public to hide their incompetence. Now we have a panicked evacuation rather than the orderly evacuation that could have been organized and widely implemented yesterday. They knew this was completely untested and had no idea how well it would work.
Bring back tar and feathers.

resistance

Looking better?
Must be some damn good stuff you’re smoking!

Jeff C

Water level is down to 901.02 feet per CDEC, that’s the top of the emergency spillway at 901 feet. If the flow hasn’t stopped yet, it will very soon. No flow means the continuing erosion stops. That’s good news and allows assessment and possibly repairs. The Butte County Sheriff stated things are getting better.
Here’s the water level hourly data:
http://cdec.water.ca.gov/cgi-progs/queryF?s=ORO&d=12-Feb-2017+20:21&span=25hours

Jeff C

Sac Bee update on the stopped flow and improved situation on the emergency spillway:
http://www.sacbee.com/news/state/california/water-and-drought/article132332499.html
Who knows how bad the higher flow damaged the normal spillway.

Steve Oregon

What has bothered me is how they earlier said the primary spillway had a routine inspection but no one walked it for a close visual inspection. Not funny since we know there were trucks on the spillway dealing with a previous repair. No one walked the thing to follow up?
Really, none of the busy water dude bureaucrats had the time to go on a lollygag walk to inspect it? It’s not like that is tough work. It’s a stroll. Gees.
What else are they not really inspecting?
I’ll have to go read Anthony’s local paper piece.

RockyRoad

…with Moonbeam Brown as governor, perhaps they figured the view from the moon was sufficient.

Greg

started referring to the emergency spillway the “auxiliary” spillway.

yes, I noticed that on one of the videos yesterday.

RAH

For now yes but this ain’t over by a long shot. More rain and snows coming. Near record snowpack in the mountains that will probably break the all time record before the melt comes. And that with the reservoir all ready at capacity! Nope, this ain’t even close to over.

Chris4692

It was pretty clear what these DWR jackasses were up to yesterday when in Orwellian-like fashion they started referring to the emergency spillway the “auxiliary” spillway.

It reflects a change of terminology in the design manuals. Nothing nefarious on their part.

MarkW

So the manuals just happened to change between last week and now.
How convenient.

Chris4692

Mark: The manuals changed a few years ago, but old times still use the same terminology they trained under. They likely are spending a lot of time with the manuals these days.

Jeff C

Uh huh, I’m not as trusting as you of their motives. It was referred to as the emergency spillway in virtually every press account and news release that I could find before Saturday. This was when they were trying to convince the public it wouldn’t need to be used and everything was under control. It was referred to as the emergency spillway a decade ago when questions were raised by environmentalists (of all people) regarding it’s soundness. The federal report that dismissed these concerns referred to it as the emergency spillway. It was called that for a reason.
Then on Saturday, when they decided they had no choice but to use it, it suddenly became the auxiliary spillway. Probably some government-flack PR specialist decided “emergency” would send the wrong message. As it turned out, the “wrong” message was actually truth as the spillway started failing at only 5% of its alleged maximum flow rate (supposedly 250K ft3/sec).
It was never designed to be used but was included as a safety valve to accommodate runoff of unimaginable proportions and prevent a total dam failure (i.e. an emergency).

Chris Nelli

According to the Sac Bee, the problem is to the left of the spillway, where the parking lot used to be. Also, not clear from the angles that the road has washed away.

Steve Oregon

Perhaps they are meaning to the left of the main spillway? They may be trying direct people’s attention away from any confusion in thinking the danger is with the original main spillway hole etc.

Richard Rall

From Redding Searchlight:
“The most recent inspection of the Oroville Dam spillway did not include a close examination of the discharge channel, according to a state dam safety report.
The last inspection on the Butte County dam, which has developed a hole 30 feet by 200 feet on the spillway, was conducted in July 2015 by the state Division of Safety of Dams.
However, rather than undergoing a close visual inspection, the spillway was checked “from some distance,” the report says.”
http://www.redding.com/story/news/2017/02/09/dam-spillway-checked-distance-last-inspection/97723936/

Chris Nelli

I take that back: the road appears gone

KevinK

I certainly hope that ANY loss of life can be prevented, and that damages WILL be minimal. It sure does seem like the understanding. predictability, and management of this event has been very poorly executed.
Everything is OK, Everything is OK, Remain Calm, Remain Calm, OK NOW RUN FOR THE HILLS AS FAST AS YOU CAN……..
Mother Nature sure can be a difficult lady, best to prepare for the worst she can offer and still hope for the best.
This could (but probably won’t) be a lesson for all those folks that think they know everything that will happen in the next 100 years with regards to the weather.
Heck, Ca was supposed to be in a permanent drought according to the computer models….
Maybe the best outcome is if everybody survives with no loss of life, limb, or property AND the “climate science computers” get drowned and can never be started up again…..
Maybe “Moonbeam” can strongly encourage everybody to wash their cars 10 times a day until the snowpack is gone……
Be safe everyone, hoping for the best possible outcome, KevinK

Chris Nelli

Yes, 30 ft high at left of spillway and probably 60 ft high on the right. But the erosion is occurring to the left of spillway where there is little concrete support. Stopping the overflow will give them time to shore up the left flank.

ossqss

Somebody did some bad math on not opening up the main spillway more earlier. How does that happen! Was ther some environmental activist concern that slowed the process of opening the gates sooner?
More rain coming this week as I understand it. Snow melt season will turn this into a global warming problem in the next few months. Just sayin……

eyesonu

I’m sure the reason that the emergency spillway was never tested was due to environmental regulations regarding silt. The overflow channels are now clear/clean. When repairs to unforeseen issues with regards to the emergency spillway are completed another controlled test should be done at even higher levels over the top. Of course the primary spillway needs to be fully operational at the time. A controlled risk is much preferred over an uncontrolled disaster.
Anything that has an emergency purpose needs to work in an emergency, not create one.

D. J. Hawkins

The only way to test the emergency spillway is to deliberately overfill the catchment. It’s a little like starting a fire in the middle of the building to see if the fire alarm system works. Not the best idea.

eyesonu

If it had been tested and the primary was capable of handling 200,000 cfs the weakness would have been identified and addressed.
It could have been a true disaster if more rain had continued to fill the lake. The fire analogy was weak.

D. J. Hawkins

So your solution to testing is to deliberately create an immanent threat to life and property in order to test the emergency spillway??? I am reminded of the Bugs Bunny cartoon where he’s testing warheads with a hammer…

Steven F

They were not using the main spillway at max capacity because it is damaged and erroding. They tried to adjust the the flow to minimize the damage but then they couldn’t keep up with inflow. And it went over the never used emergency spillway. Now they have no choice. Use the main spillway at full flow and drop the level down until the main spillway is dry, Then they canpatch it up.

ossqss “Somebody did some bad math on not opening up the main spillway more earlier. ” maybe they took common core mathematics.

Gonzo

They’re are in real trouble. This is not a late season storm system. WAY more water/storms is heading their way. Add in melt runoff later. This could get really ugly. Hopefully it’s not a complete failure.

See, if there had only been more expansive safe spaces around gender study classes, this never would have happened.

David L. Hagen

Possible Innundation Areas from Sacremento Bee News twitter feed
https://twitter.com/TroyJBarnhart/status/830968773679030273/photo/1
https://twitter.com/sacbee_news

nc

I believe the inundation graphic is for a complete dam failure.

Jeff L

For those of you unfamiliar with this area,and because there is no scale bar on the map, that’s 35 miles from the dam to the west edge of inundation. And 45 mi N-S, although the area clearly goes further south off the map. That’s a huge area !

RT Rider

Was this spillway damaged previous to the spill and unrepaired, or was it caused by cavitation? If the first, it’s negligence. If the second, then it’s poor design.

Richard G.

Note that the damage is below the point where the slope of the chute steepens. Bernoulli’s principle: when velocity of a fluid increases the pressure decreases.
Below the inflection point is where the velocity increases and thus cavitation is probably the culprit. When cavitation occurs, pockets or bubbles of vacuum are created on the surface of the chute at the interface with the fluid. When the vacuum collapses a water hammer effect occurs which plucks the rock or concrete out in chunks.
The concrete is being ‘jackhammered’ out by the water.

Steven F

The main spillway looked narmal before they used it. But when the turned on the flow part of it collapsed into a void.Cvitation caused it to quickly grow. By the time they turned off the water they already had a hole too big to fix in the time they had. There is no easy way the inspect for voids under cement.

Steve Oregon

If the E spillway holds, including the base of it etc., with that much water running over it then a congratulations to the engineers 50 years ago will be in order.

Ozwitch

This seems like a badly designed and maintained dam. An emergency spillway should not erode like that, it should be designed to cope with probable maximum flood levels, and why the heck were there trees and brush and power lines across the thing? Evidently they never thought it would happen. And the main spillway has shown seepage problems for several years but they’ve just patched it up. Nobody took the possibility of flooding seriously? Of course not, it’s California!

TA

http://www.mercurynews.com/2017/02/12/oroville-dam-feds-and-state-officials-ignored-warnings-12-years-ago/
Oroville Dam: Feds and state officials ignored warnings 12 years ago
“Three environmental groups — the Friends of the River, the Sierra Club and the South Yuba Citizens League — filed a motion with the federal government on Oct. 17, 2005, as part of Oroville Dam’s relicensing process, urging federal officials to require that the dam’s emergency spillway be armored with concrete, rather than remain as an earthen hillside.
The groups filed the motion with FERC, the Federal Energy Regulatory Commission. They said that the dam, built and owned by the state of California, and finished in 1968, did not meet modern safety standards because in the event of extreme rain and flooding, fast-rising water would overwhelm the main concrete spillway, then flow down the emergency spillway, and that could cause heavy erosion that would create flooding for communities downstream, but also could cause a failure, known as “loss of crest control.”
end excerpt

The real question here is why they didn’t let more water out of the reservoir in January and December when they had the chance. It looks like they were being way too conservative with the water in recent months and so didn’t have enough space in the reservoir to handle the recent inflows. http://cdec.water.ca.gov/cgi-progs/queryDaily?ORO

Steven F

The main spillway can only be used once the water gets within about 50 feet of the top of the dame. They reached that level only a week ago. Keep in mind that the dame was almost empty 2 years ago and mostly empty in september of 2016.
They do have a power house which can drain the lake at any level. However it cannot keep up with the flood level inflows that started in November. In a normal year they leave 1/5 of the lake empty and only fill that after the rains have ended and the snow starts melting.

Steve Oregon

Oh well that was fast. I see from Jeff C above the water level has dropped and is no longer running over the emergency spillway at all.
http://www.sacbee.com/news/state/california/water-and-drought/article132332499.html
8:15 p.m.
Lake Oroville water levels have fallen to 901 feet, the level at which water flows over the emergency spillway, state figures from 8 p.m. show.
That means little or no water is likely coming over the emergency spillway – and the threat of collapse due to erosion has diminished said Joe Countryman, a member of the Central Valley Flood Protection Board and a former engineer with the U.S. Army Corps of Engineers.
Read more here: http://www.sacbee.com/news/state/california/water-and-drought/article132332499.html#storylink=cpy

Windsong

David DuByne’s video from early this (Sunday) morning eerily accurate. So far.

The live feed reveals a fascinating, though perfectly predictable, example of what an emergency evacuation looks like — total automobile gridlock.
Here on the Oregon coast, if there is a massive earthquake, getting in one’s car to escape the soon-to-arrive tsunami is the kiss of death. It’s by foot or bike (or motorcycle I suppose), or kiss your booty goodbye.

commieBob

If you’re evacuating from an emergency at the same time as everyone else, you’re in trouble. The trick is to not live where there will be a flood. If you’re expecting a flood, the secret is to get out before they declare a mandatory evacuation, same for a forest fire. We learned a lot from Katrina.

But all the planning in the world can’t be successful if people aren’t ready to evacuate. Some say that, as long as the memory of Katrina remains fresh, New Orleanians will never hesitate to flee. But Renne still worries about complacency. “We’ve now gone a number of years without any hurricanes and there are people who have moved to the city who have never experienced a hurricane evacuation,” he said. “We are fighting a constant, uphill battle to make sure that people are aware of the risks that Mother Nature places on us.link

Consider a bug-out bag.

Retired Kit P

Why not wait for a helo to get you off your roof? Then you can blame Bush for not getting their fast enough.

My tsunami bug-out bag is pretty sweet.

Richard G.

And people ridiculed Noah when he built a boat in his yard.

Jeff L

GFS showing 6-10+ inches for headwaters above dam over next 16 days… even if all is good now , still stormy weather ahead & a lot more rain coming , in terms of maintaining the integrity of this dam. This is going to be an interesting story to continue to follow

Arthur Morrone

Governor Moonbeam saved the money for the HSR project. LOL

u.k.(us)

IFF the foundation of the emergency spillway has been compromised, its ultimate failure may take days or even weeks, gotta drain the lake to reduce the pressure.
Ain’t outta the woods yet.

hunter

Skeptics are once again proven correct and climate obsessed people are proven wrong. The drought was not permanent, and the governments should have stuck to building up infrastructure to protect people, property and environment from floods. So in Australia completely preventable flooding hits due to cliamte obsessed policies. And California may lose a major, not very old, dam due to climate obsessed policies.
Is there anything that climate change obsessed people can’t make worse?

joelobryan

But Hey!! Gov Moonbeam has his carbon tax $billions to spend on a medium speed choo-choo train, a train that no one will ride, from Fresno to Bakersfield.

RockyRoad

I hope the train route doesn’t go over any drought-swollen rivers.

dp

The emergency spillway connects to a simple buried barrier near the corner of the parking lot and it is at this joint that water was spilling and eroding the soil that holds up that wall. Had the erosion continued it would have been that wall, not the emergency spillway that would have failed. From images seen on Google images that is all loose filler, not bedrock, on both sides. The entire parking lot would have washed away and the slope would surely have been scoured away to a depth of 10s of feet or more.

hunter

….And: If the dam is structurally weak and has to be drained, then the loss of this precious water and the resulting damage the lack of flood control on this river is *all* on the heads of the climate concerned who diverted money from maintenance and improvements of basic flood infrastructure into scams like large scale solar, high speed rail, and wind.

Don

We need money for bullet trains, not damn dams. (sarc)

hunter

Moderator, If my earlier post used symbols not allowed please accept my apology. Here it is without asterisks:
….And: If the dam is structurally weak and has to be drained, then the loss of this precious water, the resulting damage to the dam, and the lack of flood control for several years or more on this river is all on the heads of the climate concerned who diverted money from maintenance and improvements of basic flood infrastructure into scams like large scale solar, high speed rail, and wind.

joelobryan

http://i65.tinypic.com/2v3hrbk.jpg
The water from the emergency spillway *will* cut an uncontained channel across that barren hillside to the Feather RIver. It will happen as surely as the snow in the mountains to east will melt.
THis cut will deepen and widen over the next few months as continued rainfall and Sierra snow pack melt will flow into the Lake.
The dam itself is not in danger. But much of the stored water behind the dam could flow south towards Sacramento *if* the erosion channel grows large enough. Big IF.

Because they neglected the Dam’s need for repairs and updates,it cost a lot more money now,trying to prevent the probable disaster, that if they just did their job maintaining it.
It would have been a lot cheaper if they LINED the Emergency Spillway with Concrete, which would prevent back erosion from occurring, to keep the structure in the area intact. Now they might lose a lot more than just the spillway……..,Huge repair bill coming up.
This is classic government screw up.

And added large and heavy riprap. The water should have been slowed and not allowed to channel.

Steven F

You are assuming they were neglecting maintenance. There is no evidence they were. They were doing their normal visual inspections and saw nothing of concern. Unfortunately no one has X-ray vision which would have been the only way to see void under the main spillway. All dames in the US and much of the world use visual inspections.
WHEN was the last time you did a visual inspection of your homes foundation? Are you sure there isn’t a sink hole under it?

catweazle666

“WHEN was the last time you did a visual inspection of your homes foundation?”
Within the last twelve months, actually, when the cellar flooded to a depth of around six inches during a very heavy storm so I dug a sump and installed a submersible pump to stop it happening again.
In any case, there is a difference between my home being damaged by a sinkhole and a dam failure potentially endangering the lives of hundreds of thousands, especially when the potential for a problem was pointed out over a decade ago.