Bishop Hill Global warming and Oz floods
Jan 14, 2011 Climate: WG2 There is a great deal of interest in this article, by Brendan O'Neill, which examines the possibility that the flooding in Australia was made worse by an earlier decision by the Queensland government to keep water levels behind the Wivenhoe dam high, since they were expecting global warming driven drought to be a problem for the foreseeable future.
The Queensland government’s belief that water conservation should be a key priority in this speedily warming world of ours appears to have led to the situation where local dams were allowed to get dangerously full. So in recent weeks, the Wivenhoe dam was running at 150 per cent to 180 per cent capacity, which means that the authorities had to start releasing water from the dam at the same time that the rain-caused flash floods were hitting Brisbane’s river system – effectively contributing to the deluge. It is surely worth asking, at least, whether Queensland officialdom’s embrace of the ideology of climate change, its fervent belief in future manmade drought and thus the need to store as much water as possible, made it unprepared for the current flooding of the Brisbane area.
Reader Comments (25)
So does climate lead to weather or weather lead to climate? Or does weather not equal climate or....? I'm still confused.
How can a resource be >100%?
A possibility is a deliberate emergency overcapacity for handling a deluge.
That would suggest the correct management is that on reaching 100% total overspill occurs returning the lower river reaches to their natural flow state. A deluge is caught.by the dam as intended.
The alternative situation is a gross misuse of public funds, building larger and more expensive than required. This does assume the overcapacity is actually safe in itself.
I think a full explanation about the overcapacity is needed.
Idealogical convictions leads to illogical and uninformed decision making, with sometimes tragic consequences and this seems to be one such example. Among others were the fires in Victoria which claimed so many lives due to the build up of undergrowth which people were not allowed to clear. There was one case of a home owner who defied the local council and cleared the area around his house, and was fined $40,000 for his effort. Of course, his was the only house left standing in the area after the fire. And to add insult to injury, instead of apologising, the council insisted on payment of the fine even afterwards. They will never learn.
And how many deaths do you think have been caused in the U.K. in the last couple of winters through the artificial rise in the cost of fuel to appease the gaian gods?
TimC: The 100% part refers to the water supply function. The amount over and above that refers to the flood protection function. The releases seem to have been increased on Tuesday to protect the dam overtopping - there are some 'plugs' like fuses, designed to blow, as I understand it. Given the lag between release and Wivenhoe and arrival at Brisbane, the question is whether that increased release should have come earlier. The Lockyer River flash flooding in the headwaters came around noon on Monday. Why was the rate of discharge maximised as soon as that occurred - or sooner, given the fact that the catchment was saturated so any rain would quickly become run-off?
Indeed, the deep LA Nina was known. The Mayor of Brisbane deferred his holiday in December in anticipation of a high flood risk, so why was the flood control capacity of Wivenhoe all available - ie 100%, even over the preceding weekend?
Iren: human actions always affect impacts. I visited friends in Kinglake who survived the fires in a brick garage as the fire front swept through three times. I drove up the road where many died trying to escape, only to be trapped by trees which fell across the road. As my friends pointed out, they were allowed to grow right up to the verge (much more attractive); in Canada, they are cleared well back from any road. We can either prepare for disaster to minimise harm, or we can hope it won't happen.
At least the flooding in NE Tasmania has ended: our daughter has been camping there with friends, so much texting and checking of weather radar has been going on!
My understanding from other forums is that these dams are triple purpose, water, flood prevention and hydro power so their full capacity is 200% of which 100% is to provide water. But common sense would suggest that prior to a known flood season you would drop the water % in prepartion for flood defence and then as the floods receded butbeore the rainy season finished you would increase the water %.
Leave the planning in the hands of those employed to do the task. Simples.
I read a post the other day at EuRef (I think) where someone noted that Gillard spent as much time defending the Water Restriction Policy as she did offering condolences to affected families. Looks like his suspicions were correct
shhhh do not mention anything alarmists were trumpeting a few weeks months ago shhhh
Do keep the "tone" of the debate very friendly , please.
the feral harsh tones hv are to be used only for when a non-socialist is in power.
It appears that a belief in AGW, not AGW itself caused the flooding.
If you believe the future holds only drought, why would you build flood control systems? Only if you believed the climate worked in cycles, that the previous floods would return, only then would you prepare.
JoNova also made this point on her site yesterday or the day before - the dams were maintained nearly at capacity, and could the problem have been eased by earlier alarms?
I suggest (only from the news films of course) that there is/was an almighty amount of rainfall well beyond the capacity of any reservoirs to cope with.
The real problem in my opinion is that the 'Decision-Makers', world-wide, continue to delude the public, based on data from their 'non science' predictions: they couldn't have coped, but they might have been seen to be doing their best.
One of the best critical analyses in The Australian this morning:
http://www.theaustralian.com.au/news/opinion/damned-if-they-do-damned-if-they-dont/story-e6frg6zo-1225988018615
Note, again, this:
8 March 2010: Courier Mail: Wivenhoe Dam ready for big spill in Brisbane River But Premier Anna Bligh and water managers say there will be no easing of permanent water saving measures. “We can’t be complacent and we must treat water as a precious resource not to be wasted whether our dams are 50 or 100 per cent,” Ms Bligh said… http://www.couriermail.com.au/news/queensland/wivenhoe-dam-ready-for-big-spill-in-brisbane-river/story-e6freoof-1225838427960
I think it is worth checking out the post by a local Queenslander to be found on the "Australian Climate Madness" blog. It puts much of what occurred into chronological and technological perspective (including that it is highly unlikely that the dam which wasn't built, would have made any difference). Bottom line - it's happened before, it'll happen again and there's really not much you can do about it except get out of the way.
http://www.australianclimatemadness.com/2011/01/queensland-floods-a-locals-perspective/
Cheers.
the absurdity of SEQ Water sitting on enough water for the next 8-10 years:
12 Oct: Australian: Andrew Fraser and Jared Owens: Water until 2018, and it didn’t cost $9bn
DRENCHING rains have delivered southeast Queensland enough water to last until 2018 without another drop falling from the sky.
However, the state is still paying for the $9 billion spent only two years ago for a water grid to “drought-proof” the region..
While there is currently eight years’ water supply in the dams, if this extra infrastructure were to keep operating, southeast Queensland would not run out of water until 2021…
http://www.theaustralian.com.au/national-affairs/water-until-2018-and-it-didnt-cost-9bn/story-fn59niix-1225937390684
ratepayers are paying exorbitant prices for water to pay for the $9bn water grid (incl a $1bn desal plant on the gold coast which is to be mothballed) and will never use the water at the main brisbane dams. even the 100% water supply capacity of the massive flood mitigation dam, wivenhoe, needs to be kept below 50 or 60% as far as i have understood it over time, but we have a CAGW Premier who thinks there's nothing wrong with having the dams at 100%. it is so crazy and the issue is so under-reported, it's hard to have a rational discussion.
Why is the media reporting on global warming so biased in favor of those supporting it? Shouldn't there be two sides to every story? Why are all the western governments pushing for global warming taxes when the science remains unproven? Why do people still believe that hypocrite and snake-oil salesman Al Gore?
Al Gore has no friends and is just using global warming to get attention. His own wife divorced him and his children are on drugs and booze because of him. I'm super cereal.
By the way, there's no possible way for America to pay back its debts. Even if Americans passed a carbon tax, they still couldn't overcome their budget deficit. They can't print money forever. I look forward to the day when China buys America and turns it into a sweatshop. Of course, America could always go rogue like North Korea and threaten everyone with nukes.
Before second guessing the resource managers, one would need to know how they determined the amount of water held. Was it based on drought cycle history, flood cycle history, climate change predictions, agricultural interests, etc. and what were the weightings applied to each. Do we know this?
Mark my words. The western nations will be punished for their arrogance and for pushing this global warming scam against the rest of the world. Jared Loughner is just a symptom of the cancers eating America from the inside. If this global warming scam is not stopped, and its perpetrators not punished, then prepare your family and kids for HELL ON EARTH. STOP THE UN before the fascists take over.
I don't understand all the confusion. Global warming causes drought and flooding everywhere. What's so hard about that then?
David44,
Maybe I can assist with your question "one would need to know how they determined the amount of water held." A large part of my job, and my speciality, is managing hydro storage in dams for hydro power generation. Although I am not familiar with the Ivanhoe dam, the basic procedures are still the same.
Each dam has a normal operating range, ie. a minimum level and a maximum level at which the water behind the dam can be used for its normal purpose. This may be electricity generation, irrigation, or town water supplies. Above this operating range is a design flood range. This flood range is used to limit the peak flood flows by applying a table discharge. At each level above the maximum operating level there is a minimum flow that must be released up to, but not above, the expected peak inflow. eg at one of the dams I control we release 850 cumecs at maximum operating level and an additional 70 cumecs for each cm rise in lake level into the flood range. This release via spill is mandatory, and any operator who doesn't follow it is liable to be dealt with very severely.
Above the design flood range is an extreme flood range. As the name suggests, extreme measures are now required to protect both the dam and the people living downstream. The amount of water released is increased to attempt to match inflow and outflow and civil defence procedures are put in place. In my 40 years of hydro operations and control I have only ever seen two such extreme events.
It appears that the table discharge release was not carried out at Ivanhoe, and they moved directly into the extreme event. Who ever made that decision to hold operational water in the flood range should be prosecuted.
I suppose its too simplistic to suggest that it might have been a good idea if the people managing the Wivenhoe Dam had kept one eye on the Brisbane flood record graph...
Not only is the Queensland premier an AGW loon, she made her husband head of the state department of climate change. Nice work if you can get it.
One of the reasons Wivenhoe wasn't at the optimal 60% was because few new dams were built over the last 20 years while people were flocking to SE Queensland from other states. This has reduced the water storage per person so as to make running out more likely. Hence the authorities were keen to maximise the amount of stored water. We were told there was no point in building new dams as they wouldn't fill because the rain would be much less due to climate change.
The wet season isn't over yet. If there's a cyclone this flood may only be the first Brisbane flood of 2011.
A visit to SEQwater's website proves that Brendan has his facts wrong.
Over recent weeks,Wivenhoe Dam has NOT been kept at 150% to 180% capacity as he claims. It is operational policy to lower the dam's flood holdings,and return the dam to 100% ASAP,to preserve the 1500GL or so flood reserve which makes up the majority of the dams overall capacity.
Throughout December,the water managers generally kept the dam at 100% when possible,in accordance with operating procedures. It has been a wet month,and the dam's flood capacity-which starts at 100% of water supply capacity and goes as high as 230%-was called on a couple of times during smaller floods.At these times the dam rose to 111.7% and 123% respectively,and water was released as quickly as safe to get levels back to 100%. So,no hint of Brendan's "150 to 180%"
After the 123% event,the dam was lowered towards 100%,shedding 250 Gigalitres in the process,and was down to 102.1% when the latest and soon-to-become worst flood started to arrive behind the dam. At the same time a major downstream tributary was in flood so dam releases were restrained. However,as inflows into the dam also increased over the next days,Wivenhoe discharges were increased,though not enough to outweigh inflows. This all has to be seen in the context of the river below the dam which was in minor flood for most of this time. The river has many low level bridges and floodplain residents,so massive amounts cannot be discharged without much co-ordinated warning. 100GL/day is more than enough to produce minor flooding...
By Friday the dam was at 107% and slowly rising even while increasing discharges. Then the really heavy rain hit over following days [9-12th inclusive] and the dam rose rapidly to close to 190%. This rain,while forecast,became extremely heavy towards the end of that period,and inflows were absolutely massive. Outflows were managed at all times ,but had to be increased to very high levels,because in the last hours of the deluge, it was becoming likely that the dam could reach overtopping heights if rain rates maintained their intensity for a few more hours..
Fortunately heavy rain rates ceased quite abruptly across the basin late on the 12th.
The dam was designed for water supply and to mitigate large and extreme floods-NOT prevent them..and in the circumstances it worked pretty well.If it had not been there the flood would have been likely higher than 1974,though not as long as that event.
Wivenhoe did not 'effectively contribute to the deluge'. It did not prevent it,it modulated it. Like any mitigation dam should,it shaved the peak and spread it over the back half of the flood..and the peak is the worst thing.
I hope Brendan will revise his piece,when he checks his information.
Thanks Nick,
That puts a different perspective on events. Your data shows that the dam was operated according to standard procedures which is what should be expected. In that case I hope there is a commission of enquiry to sort out the facts from the various claims.
Not to worry, the managers of the dam will no doubt select and pay a truly independent one.
Nick
I think the pertinent question is why was the dam not returned to 60% in December, as it was intended when it was designed?
That would hav left 140% available when the flood came in January.
Now, an easy answer has been provided by Mike B above, who states that the move to above 60% was due to the absence of new dams to meet demand from the rising population.
That sounds ok until you remember that the desalination plant was intended to meet the additional demand and to substitute for the lack of new dam capacity.
Is the capacity of the desal plant not sufficient?
Or were those in control blindsided by AGW dogma?
This needs investigation.
It should be a matter of fact, not opinion.
Is the desal plant large enough or does it need urgent extension?
The next drought will surely come.
Or do the operating instructions need an urgent overhaul?
A spring cleaning, throwing all the AGW guff out and letting some sanity in.
The people of Brisbane need three things:
* Clear eyed personel paying attention to the coming short term weather and with a flexible approact to dam management and to advice of danger, promptly given to the public
* Mainteance of the proper operating rules for the dam in the light of the above
* Sufficient auxilliary water supply in times of extended drought.
Protection from drought and flood are not either or choices.
Both are essential.
Clear, dogma free analysis is a must.
In drought - fear the coming flood.
In flood - plan ahead for the next drought.
Whistle and sing Dixie at the same time.
It surely is not beoyond the ability of stable, clear eyed people.
AusieDan, have a look at my post above about dam operation. Any dam is designed to be held at 100% of its normal operating range at all times. Above this is the flood range which should not be entered unless there is, well, a flood.
If it was designed to held at 60%, then that would be its normal operating range, and now this gets confusing because suddenly 60% becomes 100% of its operating range.