UPDATE: Drone video over spillway added.
Collapse of emergency spillway expected, evacuation ordered
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 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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Another example of how engineers get held to a slightly different standard to climate scientists.
Just homogenise the data to say that the dam is only half full.
They already are calling the emergency spillway the auxiliary spillway.
Yeah, as I commented above, that seemed to start yesterday and was the first clue the DWR was more concerned about managing perception than reality. Unbelievable. Heads should roll but they won’t.
Water level is down to 900.70 feet as of 9 PM, 4 inches below the top of the emergency spillway.
Hope I’m not right, but the failures seem to be cascading.
I’ll bet there are many dam engineers that haven’t been outside in a while, personally inspecting tailraces.
The Sheriff of the county ordered the evacuation. In his discussion he noted that one consideration he had to take into account was that there was no model of what would happen if the emergency spillway was comprimised.
The lack of an engineering model and the uncertainty that creates was enough for him.
Note: he is not a hydrologist
Note he did not calculate costs or probabilities.
Uncertainty, lack of good models, is never an excuse for in action
[Cory Honea is a personal friend of mine, and he doesn’t make snap decisions. until you become the Sheriff, and until you deal with issues where lives may be at stake, THEN you’ll have the right to criticize, as it stands, your opinion is just whining -Anthony]
You missed my point.
He made the right decision.
To everyone who says we need validated accurate models to make decisions, consider the wisdom of this Sheriff
To everyone who says you have to have a degree or be a scientist or engineer, consider the wisdom of this Sheriff
To everyone who thinks you need perfect information to make a decision…. ya.. consider the wisdom of this Sheriff.
As he said, he made the decision because of the lack of good information about what the consequences would be.
If there’s no model to assess the risk, that is NOT the fault of the sheriff who finds himself without the means to make an informed decision.
In view of the massive risk to life , I would imagine he will be erring on the side of caution in ordering the evacuation.
Can we all agree, that at this point, while things seem to be going from bad to worse on every update, it has become out of control.
It has turned into a learning experience.
Greg said:
“If there’s no model to assess the risk, that is NOT the fault of the sheriff who finds himself without the means to make an informed decision. ”
Who is at fault for there not being a model is not the point either.
This is the point:
“The Sheriff of the county ordered the evacuation. In his discussion he noted that one consideration he had to take into account was that there was no model of what would happen if the emergency spillway was comprimised.
The lack of an engineering model and the uncertainty that creates was enough for him.”
You just damned all of the climate change movement there Steven.
“Uncertainty, lack of good models, is never an excuse for in action.”
The Sheriffs lack of good information goes right back to those authorities giving the briefings. The tells which indicated they were not being forthcoming while making all those reassuring noises was when they started referring to the emergency spillway as the “auxiliary spillway”. And more importantly emphasized that the “auxiliary spillway” was not being used to even near it’s capacity while they continued to use the damaged primary spillway. That just did not add up. Those guys giving the briefing knew information that was not good news and did not divulge it for whatever reason.
i read that as he did the RIGHT thing An**ony
calling evacuation was the wise move
good on him!
Why attempt such a ridiculous analogy, Mr Mosher?
There are no models, but simple observation indicates a resonable probability of many deaths in hours.
Contrast it with AGW claims models are accurate and they are certain (science is settled) that some random bad things will happen in 30-80 years, while simple observations contradict pretty much everything they say?
You can use his words as example AFTER your side admits that science is not settled, you know very little about what’s going to happen, your models are total garbage and start having real honest discussion about climate.
The difference Steve is that this is a real and obvious emergency.
The claims that CO2 is an emergency is not and never will be.
Mosher
I hope you understand my (increased) skepticism.
You’re actually conflating the utterly predictable failure of a poorly designed & maintained dam for which weather/rain data and failed inspections actually exist (but were willfully ignored by state dam engineers & managers who simply didn’t do the analysis) with CAGW, which has no credible (adj just about equal claimed warming) data, no testable theoretical statement of cause & effect, refuses to make scientifically testable predictions, and can’t differentiation between natural & man-made warming from the Little Ice Age.
Part of the normal development of the human brain is the ability to successfully identify & prioritize threats. Yea, I could get hit by a meteorite tomorrow, but I’m not looking to spend $1000 on an iron umbrella.
You & Prince Charles may believe in this stuff, but a lot of the rest of us will take a pass.
There have been many structure failures throughout history which we have seen or read about to guide such “un-modelled” decisions.
The world has never heated to catastrophe, ever.
However, it HAS cooled to 6C below present day temperatures, and we have good evidence of the results in the fossil records.
“lack of good models”
“Good models”?
You wouldn’t know a good model if it ran under your bridge and bit you on the snout!
There’s a difference between models as used by engineers and computer games used by English majors playing at being climate “scientists”.
It will be interesting to see how the authorities handle the evacuation. How long will it last? With more rain coming later in the week will they keep people away for days, or will they let them return home and then potentially evacuate them again? And, as with any mass displacement of people, there are real risks to life and limb. What if there are casualties — directly or indirectly — from the evacuation(s)?
This now appears like a $Billion washout.
I wonder if Moonbeam Brown will be threatening the White House for assistance.
Ha!
Does California still want to secede?
After the check’s in the mail…
Global Warming froze their brains. The power, self-righteousness , and money made them as irresponsible as any government in the history of the world. This is the tip of the iceberg.
“More frequent and severe weather
Higher temperatures are worsening many types of disasters, including storms, heat waves, floods, and droughts. A warmer climate creates an atmosphere that can collect, retain, and drop more water, changing weather patterns in such a way that wet areas become wetter and dry areas drier. “Extreme weather events are costing more and more,” says Aliya Haq, deputy director of NRDC’s Clean Power Plan initiative. “The number of billion-dollar weather disasters is expected to rise.”
Yeap. Somebody’s brain is frozen.
“More frequent and severe weather
Higher temperatures are worsening many types of disasters, including storms, heat waves, floods, and droughts. A warmer climate creates an atmosphere that can collect, retain, and drop more water, changing weather patterns in such a way that wet areas become wetter and dry areas drier. “Extreme weather events are costing more and more,” says Aliya Haq, deputy director of NRDC’s Clean Power Plan initiative. “The number of billion-dollar weather disasters is expected to rise.”
This spillway is a candidate for the You Just Had One Job award. but not funny
I think let’s not worry about what they could’ve done and worry about what is possibly going to happen. No one can predict the weather or mother nature. It all comes down to this simple fact “SHIT HAPPENS” now they know and will probably do their best to fix this problem for future issue’s.
You are making an assumption, Amy, that Moonbeam will change his attitudes toward global warming over this. Chances are good that he’s going to blame it on AGW and not any failure to follow routine maintenance requirements.
Amy:
You have more faith in California politicians (and voters) than I do.
A few years ago San Francisco’s 170-mile Hetch Hetchy aqueduct had a severe lack-of-maintenance problem that threatened the water supply for a large chunk of the bay area’s 6 million people. San Francisco had so neglected the aqueduct that the state threatened to take over ownership.
Big government loves taking control (not the same as responsibility) for things, but it generally can’t figure out how to actually deliver (think inner-city public schools). And with sovereign immunity, there are no consequences (well, I mean other than water-starved people or bursting dams).
Good luck with that “…probably do their best…” stuff.
On the assumption the emergency spillway is not breached and the impoundment lost, right now a completely separate team needs to be planning and implementing a program to reconstruct the damaged spillway as you are at the beginning of the flood season. Modula pre-cast interlock block design may be the way to proceed with the spillway structure as you will not know just how much damage will ensue from this event. A new spillway foundation with reinforced earth, precast ramparts and soil anchors lain over an impermeable geotextile may be the quickest way to proceed with the footings and should also inhibit the subsoil aquifer that was the original cause of the failure. At some point an additional functioning spillway should be constructed where the temporary one currently is. If the dam is breached it will be a true disaster. I pray this is does not happen. Stay safe.
Pretty sure there was no aquifer involved. It was the ‘ski jump’ launching millions of gallons of water into the air, only to crash back to earth repeatedly on the same spot of the spillway over and over again, that caused the ramp to fail.
When they built that parking lot did they compromise the integrity of the far end of the emergency spillway?
My understanding is that the parking lot was designed as part of the structure
Seek higher ground!:
Compare with Wivenhoe dam in Brisbane, built by a conservative government to hold back floodwaters. Labor ( cf Dems) believed that it would not rain again and overfilled it. Had to release huge amounts and damaged many houses. Currently legal action against Government over mismanagement.
Local TV station KRCR TV found a photo from 2013 showing inspection/repair activity on the main spillway at about the same spot as where the main spillway started eroding, spawning subsequent problems. Photo appears in the TV station’s news video btwn time stamp 1:37 & 1:54. Perhaps instead of fixing the problem(s) in 2014, the state government on advice of possibly AGU et al (e.g. Peter Gleick?), decided that this man-made global warming permanent drought meant spend money on high-speed rail instead? http://www.krcrtv.com/news/local/butte/emergency-spillway-unecessary-for-now-2013-photo-of-damage-surfaces-supervisor-blames-dwr/325934917
I would have been nervous had I been on the podium giving an update as the Acting Director of DWR, but I definitely would not have forget the difference between cfs and acre-feet.
This yutz says that they are running at 65,000 acre feet per second. I do feel bad for him. Where did the director go? When will a new acting director be hired?
Find competent engineers and put them in charge, and let them be responsible. Get rid of non engineer administrators and administrators that happen to have engineering licenses from cubical work that they did 30 years ago.
This is just sad.
This thread is useless. It is so lacking in information that I cannot even Express why it is useless.
What does that say about your communication skills ?
Well Chris,
From your reply under lance (7:16 p.m.) to Brian356, we have learned that Oroville is not a flood control dam….
maybe worse than useess.
You need to learn how to read.
I’ve found it very informative, maybe you missed something by scanning or not reading at all .
If you know of better sources, provide a link instead of whining. If you don’t know of anything better, I guess it is the best, so stop whining.
We aren’t giving the information that is Chris approved.
Chris 4692
I’d say a lot of that starts with the CA folks in charge of this on-going train wreck. Exhibit #1 would be the poor fool acting as the director of the DPR responsible for the dam – listening to him speak, you have to wonder if he actually knows what a dam is.
…and the CA state gov website defines Oroville as both a water supply & flood control dam
And, hydroelectric generation.
John Garamendi just stated that Climate change is real (Man made I presume he meant) and storms will be getting worse and if we could only spend the money Trump is spending on his wall, on water infrastructure things would be better. So he got a dig at climate realists and Trump as well. Being from Australia has this guy got any credibility in the US. I have read Obama helped stop funding for infrastructure spending because California will never have full dams again.
garamendi is what you call a career politician. Since the public imposed term limits to rid ourselves of deadwood like John, he has spent the intervening decades hopping from one jurisdiction to the next, taking advantage of a loophole to keep his phony baloney job.
Carpetbagger Garamendi
From the Sacramento Bee, 4:45pm today:
Flows over spillway dry up
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
Maybe it’s because of this gem study I just came across .
http://www.abc.net.au/news/2017-02-13/humans-accelerating-global-warming-anthropocene-equation/8265326
Humans causing global warming at 170 times more than natural , I’m surprised it’s not by 97 times but hey .
Something I don’t understand is, who built that road blocking the emergency spillway? There are no pylons to allow overflow water to escape. Second, the emergency spillway doesn’t appear to have anything protecting the ground behind the dam. There must surely be a major risk of undercutting the main dam from the water flow.
I cannot conceive of engineers designing a dam this way. Nor can I see a government department approving such a patently unacceptable design.
An afterthought: what does the risk management plan say about this? Somebody has to have been seriously incompetent here.
Incompetent ??
Nah, She chortles at our attempts to control Her rages.
adjectives and possessive pronouns are not capitalised in English or any other major european language that I can think of, unless referring to God in christian writings.
Maybe you are referring to God and think God is a Woman !?
Maybe.
Mother Nature is routinely capitalized. And she is a female.
Hivemind. The reality is that the main earth and rock fill dam can never be over topped as it will collapse causing catastrophe. So you design a spillway that will pass an extreme event flood such as a 1 in 10,000 year event. After that you have an emergency path for an even greater flood peak which is designed to fail by collapse before the main dam wall is breached. The emergency spillway would fall backwards when the over topping flood was perhaps 4 or 5 metres over it. This cascading failure scenario preserves the dam wall and provides time for evacuation and other preparations. The problem here is that the spillway failed by erosion and has not been operated at more than 40% capacity. The dam operator would have a set of fixed procedures to follow, firstly to cover their bums and secondly as basic operations are normally managed by technical people and not specialist engineers. In the real world, and in my experience, two things can go wrong. The first is that a human controller can be bamboozled when something unexpected happens and the second is that something unexpected always happens. Dam operators normally die from boredom. So when an unexpected circumstance arises they can be slow to process the enormity of the situation. I am not saying anything about this circumstance, but I have seen some near catastrophes emerge from very ordinary circumstances and a chain of stuff ups. A previous thread mentioned the Wivenhoe Dam above Brisbane in Australia. I knew the Dam operators by reputation and some in their organisation professionally. They are a very capable outfit. However the legally binding dam operation manual was not adequately reflective of the two contradictory roles played by that dam, ie water supply and flood mitigation. There was also a hint of political vacillation as there is always a person (sometimes persons) who must give the go ahead to operate a major spillway as there are presumed downstream consequences and some individual must take legal responsibility. Under a significant but not extreme precipitation event they managed to flood Brisbane down stream and cause huge damage to a major city. The rest of us were slugged a nation wide insurance levee for some years afterwards to pay for the insurance losses. The Oroville Dam situation still has a long way to go so it may be better to judge operator performance from some greater perspective.
Good post thanks
It is common to build a road across an emergency spillway. When the roadway is built it is shaped to channel the water to the middle of the spillway, It is accepted that the roadway will likely be washed away if the emergency spillway is ever used. Until it is washed away it serves the added function of slowing the water upstream of it thus also delaying erosion in that area.
We’re past that point now, and everyone is just holding their breath.
Hivemind
Now, now – calm down. They’ve only had since 1968 (dam opened) years to mull this stuff over. I’m almost certain they will improve somewhat in the future, just like the guys who designed the replacement Bay Bridge (Ooops! Unfortunate reference; seems that was knee-deep in incompetence as well).
If you’re a state engineer, one of the most important things to hope for is no one gets sent to jail for any of this.
Please correct me if I am wrong with these numbers:
Lake Area 25 sq miles
Height of emergency spillway wall/weir 50 feet
Volume of water that needs to be released 34 725 000 000 cubic feet
current rate of drop per the press conference 60 000 cubic feet per sec
time needed assuming the rate stays the same 6.69 days of running the concrete spillway at 100 000 cubic feet per second.
My question is can the concrete spillway sustain that rate of flow for that time period??
If not when will the dam “fail” i.e water starts running over the top of the dam and what are the consequences to the structures at the bottom of the dam and downstream?
Also loss of electrical power at the dam (flooded turbines / generators will that cause loss of control of the emergency spillway?
Again just some thought from a non engineering person.
The problem is there will be high inflow rates into the lake for the next 3-4 months. The question becomes can the outflow sustain high rates for months not days.
I agree, my question would then be l if there is no way to keep the dam from overflowing then what measures need to be implemented now to prevent loss of life ??
Also do the administrators in DWR have the moral courage to tell people you need to remain evacuated until …….. ( days, weeks, months rainstorms, snowmelt etc are done) ??
Water cannot overtop the dam because the emergency spillway is lower than the top of the dam. The danger is a collapse of part of the emergency spillway concrete structure which would result in an uncontrolled release of just the top 50 feet of water in the dam (which nevertheless is a lot of water). The spillways run down a hillside away from the dam which was a very clever decision on the part of the engineers. It means there is still no real danger to the main dam structure.
The spillways are part of the dam infrastructure. Failure of the emergency spillway would allow erosion of the substrate in that section there by leading to a breech of unpredictable size and outflow. Who knows what is going to happen! It has been a slow motion disaster in the making from the get go like two trains heading for each other. The question is will there be a collision and how bad will it be if there is one. But I would note that many of the reassurances that the authorities have given have turned out to be false.
Strictly speaking it can – and just few hours ago it went over emergency spillway height by almost 10 feet.
If inflow exceeds outflow, the height of water over the top of emergency spillway will be increasing, and if it continues long enough it will theoretically eventually reach the top of the dam.
Of course it is more likely that emergency spillway will erode first and outflow will increase “naturally”, or DPW will use explosives to open up the hole elsewhere – which, while being really bad, would still be better than letting dam collapse.
But it’s all theoretical – hope that it was designed that something like that would never happen.
RAH February 13, 2017 at 1:52 am
“The spillways are part of the dam infrastructure. Failure of the emergency spillway would allow erosion of the substrate in that section there by leading to a breech of unpredictable size and outflow.”
AFter having reviewed the topology and makeup of the small hills (rock, most likely granite) in the area, I’m thinking “no.”
Please review the specifics as to the ‘lay of the land’ and correct me if I am wrong.
_Jim February 13, 2017 at 8:07 am
RAH February 13, 2017 at 1:52 am
“The spillways are part of the dam infrastructure. Failure of the emergency spillway would allow erosion of the substrate in that section there by leading to a breech of unpredictable size and outflow.”
AFter having reviewed the topology and makeup of the small hills (rock, most likely granite) in the area, I’m thinking “no.”
Please review the specifics as to the ‘lay of the land’ and correct me if I am wrong.
———————————————–
I will correct you because I believe your wrong! How strong does this bedrock look to you? I’m no geologist or civil engineer but that “bedrock” looks like porous, punky, fractured junk to me.
http://www.drroyspencer.com/wp-content/uploads/is-this-bedrock-550×270.jpg
RAH February 13, 2017 at 6:22 pm
re: _Jim February 13, 2017 at 8:07 am
RAH writes: “I will correct you because …”
Please see:
https://wattsupwiththat.com/2017/02/15/super-soaker-atmospheric-river-taking-aim-on-beleaguered-orovilledam/comment-page-1/#comment-2426850
and
https://wattsupwiththat.com/2017/02/15/super-soaker-atmospheric-river-taking-aim-on-beleaguered-orovilledam/comment-page-1/#comment-2427901
for support of my contention.
The Oroville dam was NOT a dam like the failed Teton dam which *was* built on fissured and somewhat porous rock.
Your calc assumes a vertical walled shoreline. The bed is sloped, so the area decreases considerably with depth- how much I don’t know. But I’d guess the volume in that top 50 feet is less than half of what you calculated. Somewhere there is an area per water height table, and from that it would be pretty easy to manually integrate the volume.
If it was undamaged it could, and probably has in the past. With the damage its anyone’s guess.
I see almost no undercutting of the concrete spillway moving upslope so my guess is it can. The shape of it tends to fire water out away downslope. The lower part of the spillway will totally destroy itself, but the upper part I think will remain intact.
I have read that the Governor of California has sought Federal assistance. So a State whose contempt for the administration of President Trump is blatant now wants a bail out. While I certainly do not wish to see a disaster, and certainly no loss of life, the temptation must exist to tell the State government to deal with the problems of its own making. However there has to be quid pro quo for the help, I would start with demanding respect towards the rest of America who must fund correction of Californians own misjudgements. The arrogant disregard of some along the west coast has gone way to far. Do you hear judges of the 9th Circuit.
Sure we will help, just sign this resignation letter first…
[sourcecode]
02/12/2017 15:00 902.17 3571995 54904 46678 63875 34.76 13.4
02/12/2017 16:00 902.09 3570722 65117 41410 72238 34.76 13.4
02/12/2017 17:00 901.89 3567540 0 45998 97713 34.76 13.3
02/12/2017 18:00 901.65 3563726 99969 42369 103022 34.76 13.5
02/12/2017 19:00 901.35 3558960 99758 40485 113169 34.76 13.5
02/12/2017 20:00 901.02 3553726 99658 37441 118405 34.76 13.5
02/12/2017 21:00 900.70 3548654 0 14784 118144 34.76 13.3
02/12/2017 22:00 900.34 3542956 99231 5237 118148 34.76 13.5
02/12/2017 23:00 900.11 3539318 99080 33762 115226 34.76 13.5
[/sourcecode]
http://cdec.water.ca.gov/cgi-progs/queryF?s=ORO&d=12-Feb-2017+23:50&span=25hours
Something screwed with their data.
17:00: zero outflow ; 45998 cfs inflow yet water level subsiding.
Hope that formats OK.
Latest figure in that table shows nearly 100,000 cfs with water below the em. ( sorry “auxiliary” ) spillway.
Have they opened up the regular spillway to a large volume?
Don’t forget the power plant at the base of the dam is also discharging water.
No, that’s been shut down for days due to debris
Greg, remember, that is ‘provisional’ data, subject to correction. (Just like the note on the website says.)
When you work with flow gauges you learn that sometimes spurrious readings happen.
“officials stress that Oroville Dam itself is sound”
I don’t know about that. With all the water they’ve been releasing? I recall seeing a photo of Hoover Dam when a similar incident happened – once they got in to inspect it this is what they found:
“When engineers inspected the spillway tunnels, they saw that house-sized holes had been punched through the concrete lining…”
http://articles.latimes.com/1995-10-29/magazine/tm-62672_1_hoover-dam
The two dams and SPILLWAYS are not comparable.
Hi 4Times,
For anyone who wants to google up on this incident, the LA Times title is misleading. The spillway tunnel cavitation was actually in Glen Canyon dam, many miles upstream from Hoover. The event was real, however, and there are really scary photographs of the resulting damage.
The emergency spillway is rated at 250,000 cubic feet per second? That must be a complete lie. The soil behind it would all be gone within minutes if that rate ever occurred. Looking at some footage and the erosion, including the loss of that roadway below it, and at some 10,000cf/sec only, I could only assume the total loss of that hillside, not just the loss of the concrete emergency spillway.
The only real question, considering that they are using a parking lot as part of the spillway, is what is below that emergency spillway. Rock or dirt?
The soil in an emergency is expected to erode. There is rock under the soil. otherwise they would not have put the emergency spillway in this location.
But maybe not very sound rock. How else can the engineers be worried about erosion and undermining the emergency spillway in less that 24 hours of use?
I’m watching this discussion and thinking – “gee some people would really like for things to be disastrous”. This is the same kind of thinking that drives alarmists I think. They see a technical issue with CO2 possibly causing warming, and instead of coldly assessing the likelihood and the magnitude are eager that it be catastrophic.
My assessment is that despite the damage to the lower part of the emergency spillway the upper part is perfectly sound and in no danger. And if they just run the emergency spillway at max there won’t be an issue.
Aaagh – I meant the main spillway. Oh for an edit function!
Ian H: The upper part of the main spillway is carved in the rock.
Stephen Rasey:. The rock is a metamorphic rock , schist, per the feasibility study. Is it surprising to you that the geology was considered in the decision to locate the spillway where it is?
I see a lot of ignorant comments about what went on at Wivenhoe Dam. I suggest actually acquainting yourself with the data in detail rather than reading the politically motivated crap put out by the mainstream media. Seems like some people demand all the data be presented so they comb over it in fine detail on matters of climate change but think a cursory glance is enough to draw a conclusion in regards to the cause of the Brisbane floods.
Personally I spent a month going over all the data in minute detail to provide a 2 hr presentation on the event to the Brisbane severe weather association. This involve looking at all available weather forecasts, river levels, historical context and the lead in to the event (there was another significant inflow in October 2010 several months earlier where the type of releases clamored for in Jan 2011 would have generated significant extra flooding).
The actual weather forecasts for the event were for massive rainfall occurring below the dam on the Monday 11th and Tuesday 12th. Of course for the geniuses here who have the benefit of hindsight, it makes perfect send to make massive releases from a dam only half full into an area forecast to receive hundreds of mm of rain onto super saturated ground (at 100% runoff) that was seeing local creeks and rivers below the dam hit moderate to major flood levels in response to less than 50 mm of rain in the preceding week. I swear some people here don’t understand the concept of a dam.
For the record massive releases were occurring well before the 1/200 year to 1/2000 year rainfall from Sunday to early Tuesday that filled the dam (remember this had been forecast to fall below the dam) and caused the massive releases on January 11th.. I shot footage of the dam on the Saturday 8th Jan prior to the major rainfall hitting that was used in the National Geographic documentary on the Brisbane Floods. At that point they were already releasing 52,000 cubic ft per sec and there was already massive amounts of water going downstream of the dam.
Its now 6 years later and the class action against the dam operators began in Oct 2016. At least the courts will get to see all the evidence as opposed to the ignorant rubbish that was presented in the media about the event. I see little chance of the lawsuit succeeding.
“David W February 13, 2017 at 2:05 am
At least the courts will get to see all the evidence as opposed to the ignorant rubbish that was presented in the media about the event.”
Aussie media publishing ignorant rubbish, you jest?
Couple of things:
Remember when some sceptics convinced attendees at COP20 that Dihydrogen Monoxide was more dangerous than CO2? Seems that Oroville is about to find the sceptics weren’t kidding.
As a Brit (who lived in the USA – NC – for a few years) I like to keep tabs on things. I found the countryside round Oroville so pleasant I took a tour via Google Streetcam round the dam and the marina. What a beautiful place to live. Great houses and great views. Such a shame that the PTB can’t manage basic maintenance of the simple things. I do hope a public inquiry is held and that those responsible for this negligence get what’s coming – and aren’t allowed to plead AGW (the new 5th).
How far can you get with an electric car at night in cold weather conditions, 5 people in the car 2 dogs 1 cat , luggage etc ?
Remember there are 150,000 people going in the same direction at that same moment.