There’s already some finger-pointing about the management of Brisbane’s dams in the weeks leading up to the flood. I don’t want to deal with that while the emergency continues, but I will make a couple of suggestions regarding future policy in Brisbane and elsewhere
* The historical statistics on the frequency of severe rainfall events (both droughts and floods) have proved to be of little value. Everywhere in Australia, we need to work on the assumption that extreme events will be more common in the future than they were in the (pre-2000) past.[1]
* As regards Wivenhoe Dam, we need a much more cautious approach to flood mitigation, going into wet seasons with a substantially larger reserve capacity. This in turn will reduce Wivenhoe’s usefulness as a water supply source, and buffer against drought.
* One response that is immediately available to us is to turn on the water recycling plant, built at great expense during the drought and never used. Current policy is to turn it on when average dam levels are at 40 per cent. This trigger should be raised significantly. As a very rough guide, it appears that when our dams are at 100 per cent of normal we currently have enough storage for four years supply. If instead we cut the maximum to three years supply (75 per cent0, we could (roughly) cancel the impact on supply by turning on the recycling plant at 65 per cent (40+25)
On a personal note, I’ve had some reports from home and it appears that cleanup will go faster than expected and that our biggest loss (the car) is covered by insurance.
Many others are not so lucky. And, as was discussed in comments to the previous thread, floods in poor countries regularly cause many deaths (400 in Brazil and 40 in the Phillipines in the time I’ve been following our own flood) and wipe out the few possessions of very poor people. If you are giving to flood relief appeals for Queensland (as I hope you are), please think about also sparing a few dollars for emergency relief or long-term development aid for the truly poor.
Update It’s been argued pretty convincingly in comments here and elsewhere that the additional mitigation capacity in the estimates above would only have had a marginal influence on the current floods, given the volume of rain that fell. Still, I think the basic premise is right. We will need more mitigation capacity and that means less water at higher cost.
Another point I meant to make earlire is that more reliable forecasts of El Nino and La Nina events would be of great value in managing water supply in a highly variable environment.
fn1. I will have a lot more to say about human-caused climate change in the near future. But until I’ve had my say, I request everyone to avoid any discussion of the AGW topic in this thread – failure to heed this warning will lead to deletion and may result in a permanent ban. Feel free to continue discussion in the agnotology thread.
John Quiggin 
The question then has to be JQ, how much effect on flooding will 25% of Wivenhoe’s capacity have on flood levels? It is now going to take at least 10 years before we know if all previous climate cycles are null. Will drought return?, or are we now into a new shorter climate pattern.
The real problem is that this whole subject of water retention or release is guaranteed turmoil in a conflictual political environment. Every choice has a downside and that downside is fuel for political attack. I think that there is going to be a huge need for an independent national water management authority (may already exist) to exercise water planning on the basis of best science.
for our current flood it would not be too hard to calculate how much better things would have been with another 25% capacity in Wivenhoe. It would have helped, but not as much as one might think. Firstly the water coming from the Bremer river and Lockyer valley enters the Brisbane river downstream from the Wivenhoe dam. That was a lot of water. Secondly the Wivenhoe catchment was delivering huge inflows – around a half total capacity per day! (as against 25% = 1/8th total capacity using the measurement system of seqwater).
So it would help, but not much – the dam operators would still have had to release an enormous amount from Wivenhoe.
It seems that the rain stopping allowed the dam operators to cut the Wivenhoe outflows as the water from the Bremer and Lockyer came into the Brisbane river. Good planning and understanding of the specific system combined with luck to prevent an even greater disaster.
It seems to me that the Brisbane-valley flood was well prepared for and managed. The risks to utilities, disease and the need for information and evacuation all appear to have worked well. This is taxes at work.
Is it the case that no property was damaged that was not on a well known flood plain.
The real issues are the forces that allowed development on a flood plain.
So far it appears that elsewhere in Australia only flood plains are flooding and levees are doing their jobs.
However what happened in Toowoomba is a different issue and we need a formal Inquiry here. Did the City Council or Shire administrations have previous knowledge of the potential waterflows through various creek flats in local valley situations? What is the flood history of this region?
If they can move townships when constructing the Snowy Mountains scheme in the 1950’s they can easily move town centres off floodplains now.
Unlike earthquakes and bushfires which jump containment lines, floods on floodplains should cause no untoward or heart-wrenching damage.
Australia needs droughts and floods and you cannot over-rule nature just because some business wants to locate on a cheap bit of land, or local authority desires to skimp on bridge and earthworks costs. I would image, that away from water-front prestige, average householders on flood plains have been forced to live on cheaper sites because their incomes from work are insufficient for them to purchase a decent life.
Without a doubt the substantive issue is planning and the relationship between developer interests and the planning processes. No surprises there and the resitance to tackling that will be strong
@Chris Warren
Chris Warren is right on the money. “The real issues are the forces that allowed development on a flood plain…” or more precisely on “flood plains” plural.
In another post, I called for the progressive movement of all towns and suburbs above the 1 in 100 years flood levels. Along with this, there should be a ban on all future development below such flood levels. As Prof JQ noted, climate variability and climate change render historically determined probabilities somewhat problematic. However, the 1 in 100 level would be a good starting benchmark.
Assistance for these moves should come from the state and the state should progressively buy such land and houses at market price. The land should be returned to use as parks, natural riparian buffer, wilderness and/or grazing as appropriate on a region by region basis.
Selling out of a flood prone area should be voluntary but those who remain would be required to take certain further measures (too long winded to define here).
Where key infrastructure, like the Rocklea markets and industrial area, exist in a flood prone area, we need case studies which cost moving the infrastructure and compare that to implementing full levee protection and a raised road and rail link to a secure high-ground transport hub.
I am sure, in the long run, prevention is more economic than widespread flood recovery. Of course, there would be a level of measures beyond which we would run into the issue of negative returns. We need to examine these issues fully.
@Chris Warren
It may be that the local authorities in Toowoomba failed in some way. It may also be that the decades-old obsession with cutting spending no matter what is bearing some fairly nasty fruit. An inquiry is an excellent idea.
The Toowoomba and Grantham flash floods opened all our eyes to the power of flash flooding. Local flash floods of this magnitude in Australia have been very rare to date. They may become more common now with AGW. It’s hard to fault anybody for not predicting these flash floods. Now we have seen them in this area we may need to look at a few new issues.
Toowoomba may need some expensive new floodways which will only be fully utilised once every 50 years. The Grantham issue is maybe even more complex to address in prevention terms.
Playing politics with such events seems to be reserved for the likes of Barnaby Joyce, instantly last week into the “what we need are dams, dams, and more dams” routine. Just as with the call for ever more prescribed burning after every bushfire, the people who want to do things that will cause environmental damage seem to have free pass to politicise such events, everyone else should shut up or be accused of playing politics.
I agree, of course (again as with bushfires) that there needs to be a lot more emphasis on both city/suburban planning, and on building codes, in flood prone area, but I am willing to bet to my last dollar (not, I’m afraid, a huge amount) that calls for regulation will be poo poed by housing industry people, radio shock jocks, and right wing politicians generally, and quietly shelved.
I would also like to see some enquiry into ecological methods of flood control – eg the use of wetlands, reed beds, riverbank and hill slope vegetation – but I am betting (second last dollar) that land clearing and draining practices will continue unabated.
The Thames Barrier in London provides an example of engineering project that has been needed more often than originally envisaged and may eventually have to be replaced.
http://en.wikipedia.org/wiki/Thames_Barrier
@David Horton
what we will see David is “fast tracking” of “big mining” Jobs! Jobs! Jobs!
We could hire Delta Works, the Dutch project started after the same storms that inspired the Thames Barrier. Among the most impressive things about the Dutch approach is that it is very long term. The project began in 1953 and was completed in 2010. They also take science seriously. Within days of Katrina they had named a new commission to investigate the impact of sea level rises. The commission proposed a new project that will take 190 years to complete. The US sought (and of course ignored) their advice after Katrina. Why do serious policy when you can chant ‘Drill baby, drill’.
completely unrealistic but
wouldn’t it be amazing if all the low lying flood prone spaces were turned into public open spaces .
parks,playing areas,etc.
and
slightly off topic
any ideas on the affect to the barrier reef.
in conversation,two trains of thought are
the silt will stifle
and the reef had handled this kind of thing for aons and there is no problem.
@David Horton
Your last two dollars are safe, I think.
Wasn’t it Barnaby Joyce who earlier pooh-poohed building more dams?
I believe that developers have resorted to the courts to overturn council and government vetoes on developing unsuitable land. That should also be added to a review list, I think.
However, given the current climate of develop at all costs and the floods are the Greens’/Peter Garrett’s fault, I fear it’ll be business as usual. I hope I am proved wrong, but like you, I think my last couple of bucks will remain safely in my purse.
It would be expected that the review that will take place after the event(s) will look closely at the strategies for dam management and related issues.
Another matter that will hopefully get attention is who pays and how to pay for repairing all the damage. At the moment once a threshold has been reached, the cost to the Queensland Government is shared by all States and the Federal governments under a cost-sharing agreement.
Because the costs in this case are well above the threshold, this means Queensland Government’s costs for these floods will be shared by all Australians and not just Queenslanders. I’m not sure of the details of what is covered under the cost-sharing arrangements but it wouldn’t include individual losses.
It’s past time to look at different ways of addressing the matter of floods and other disasters across the board. Eg funding of volunteer emergency services, more equitable reimbursement for individual property damage (insured vs uninsured etc), urban and rural planning, adaptation, how to more quickly address the root causes etc etc.
The Victorian Bushfire Royal Commission made some good recommendations (and some very bad ones), but it didn’t address all these issues and for some of those it did address, it didn’t do so adequately. The review of this disaster will provide an opportunity to do it better.
It’s not possible to prevent all disasters. For example, the Lockyer Valley incident was a freak event and probably the majority of contributors to Queensland’s economy was affected by this summer’s floods.
I agree that all efforts should be made to dissuade people from building in flood prone areas, or to better flood-proof buildings on flood plains. Given that much of Queensland’s most productive lands are flood plains – as is much of the most productive land in other states – to stop anyone from living on or using flood plains for agriculture and towns that provide the requisite services would severely reduce the productive capacity of Australia.
Any changes to existing arrangements for response, relief and recovery need to take as a given that much of Australia is prone to drought, fire and flood. The focus has to be on how to best protect major centres against such events, ensure there are adequate resources to respond to multiple simultaneous widely dispersed large events (including volunteer services), ensure there are funds to pay for the cost of response and recovery, and address the root cause of the increasing frequency and severity of these events.
Some communities on the upper Mississippi floodplain in the USA either dissolved or simply moved to high ground. It is not sustainable to maintain communities that will experience hundreds of millions of dollars every year or so, or even every decade. It will be interesting to see whether the Australian goverment has the mindset of a petit bourgeois or if it will have the courage to do think big.
Don’t mean to hog John’s blog, but I must say this.
IMO, the response coordinated by the Queensland Government to the floods this summer sets a new benchmark in Australia (and probably internationally) for emergency response. It has been most impressive.
Our problems in Australia, along the eastern seaboard right down to South Australian Murray mouth, start with multi-year wets after serious drought. The largest drought breakers have been strong – as in consistent – la Nina stretches immediately following prolonged drought. The la Nina phenomena is in itself only a necessary condition, not sufficient. Although there are only a handful of serious flood events for which a decent record is available – more recent ones possessing much more data of course – it seems that a serious flood requires a one-two punch, a combination of a decent la Nina surviving across one season to spill into another, and something else, like a series of unusual summer rain events in Victoria. These may occur through meteorological structures, such as blocking highs. Anyway, the signature event of the 1956 floods along Mannum and other river towns was such a combination. Not only the Murray, but other river systems filled beyond capacity. “Normally”, river systems far apart won’t fill together, but weather being what it is…
And then there is the encroachment of humans into every good part of the environment, bit by bit. Once high ground is taken, the next band of undeveloped low ground becomes the new high ground – until the flood plains are all that is left. Murray Bridge at Sturt Reserve has a fabulous juxtoposition of this phenomenon. Perhaps 100–150 metres away from the current river’s edge are a series of multi-storey houses on high ground, with a wonderful view of the river extent. Some years later the deal was done, and the flood plain immediately beneath these houses has been developed, with clearly unprotected virgin homes. Flamin’ heck! I don’t want to have a go at anyone who wants to buy into such houses, but please be sure to have really thought about it. Just because someone was willing to take a risk developing that area is not reason enough to take a more enduring stake in the outcome by buying a home. Developers build houses, not homes. They have an entirely different view on the nature of risk.
Could the Murray Bridge council provide some clear reasons why they risked the placing of new houses so close to the river’s edge – ironically a few tens of metres from the tourist display, a post with the historical floods marked on it; the 1956 flood is the only one requiring raised eyes – and should they eventually flood again, what words they’ll use to placate the angry (ex-) residents? Maybe I’ll attend the next council meeting…
The 1956 floods around my location are a case in point. It isn’t good enough to plan again “for a 1956 flood”, or “for a 1974 flood”, or whatever. The point is to decide upon how to
BCC have had a flood prone property buy back scheme that very few took up in the past years….
http://www.couriermail.com.au/news/queensland/flood-residents-stay-on/story-e6freoof-1111117145726
I keep hearing this “flood plain” business being bandied about by people who obviously don’t know much at all about Brisbane’s geography. Its only really straight-out flood plain is around Rocklea, Oxley and the river mouth where Tingalpa and the airport are. Lots of this area is light or heavy industrial as is typical of any Australian city (the Marrickville area, anyone?). The river winds its way among hilly country. The rest of Brisbane, including the hardest hit areas like Milton and Indooroopilly, is actually built into riverine hills. Brisbane is HILLY like Sydney east of Parramatta, not flat and featureless like most of Melbourne.
When it floods the river backs up the creek beds and the former creek beds up streets and floods these. This is why some houses go totally under and the next street is untouched. The pattern of this flooding is known, sure, but many of these areas are also Brisbane’s OLDEST areas, much of it is pre-1946 housing stock along with more modern development (duplexes, townhouses) on subdivisions of the existing bigger blocks.
Sometimes in big storms we get the opposite problem (like Toowoomba). The water rushes down the gullies to the creek beds and river beyond. A lot of the drainage system is built to withstand this issue, not the opposite one (the river coming back up the stormwater flows).
This is a commonsense article on dams and flood mitigation.
http://www.brisbanetimes.com.au/opinion/society-and-culture/building-more-dams-is-no-way-to-prevent-flood-catastrophe-20110111-19mkm.html
Dr Vervort mentions the two methods of catchment management. “preventing floods by focusing on land management, increasing infiltration and slowing down the water before it reaches the stream” and “the second part of the risk equation, reducing damage rather than occurrence. A key element of this type of management involves *limiting development* on flood plains to allow the river to run freely.”
Obviously the powers that be have failed to use these catchment management strategies, except perhaps for interpreting the “slowing down water before it reaches the stream” as whacking a dirty great dam in somewhere. This has been of value only in less than major floods.
I think the dam – Wivenhoe – did have value, and we need water storage anyway. But clearly the idea that the only way to manage living in an environment is through massive physical and technological intervention is deeply flawed.
Unless of course your primary goal is to make money within your own lifetime.
@Salient Green
really good article from Dr Vervoort though
Just about any problem Australia faces has population growth mixed up in it somewhere (more often than not as a root cause) and this issue is no different; a rapidly expanding city and settlement in flood prone areas plus stretched water resources. Until governments of all persuasions govern for the majority rather than vested interests and short term political horizons the severe problems caused by unecessary population growth can be expected in all manner of areas.
@gregh
Massive populations = massive physical and technological intervention
Massive population is the path humanity has chosen and is choosing. Having a massive population is clearly more important to humanity than avoiding the problems it causes and will cause.
It appears that SEQ Water may have stuffed-up big time in controlling the flow of water from Wivenhoe dam. For some reason they allowed the level of Wivenhoe to rise from 106.3% at 6 am on Friday the 7th to 148.4% at 9 am on Monday the 10th, a period when they could have released all inflow without causing any major flooding in Brisbane. That extra 42.1% could have saved a lot of water going down the river during the flood peak. Perhaps they don’t have funding for flood management staff over the weekends. They probably save an enormous amount of money with this policy, more than enough to cover the cost of being sued, er, maybe not.
As mentioned earlier, the Dutch are pretty good at this and as usual, are a bit ahead of the game. See images for Netherlands floating houses.
This is not to minimize the disaster or problems from not being careful where you build, but some infrastructure really does want to be at river-edge or sea-level.
For seal level rise, her’s a map centered on Brisbane. Run the SLR up and down, make your own planning estimate of SLR for 2100 and 2200AD, unfortunately limited to integer #s. Just as a guess try 1-2m and 4-6m.
Note: dikes against storm surge and against SLR are different. For the latter, if you are below sea level, and it rains, you have to pump the water up.
@Chris O’Neill
It is too early to make the strong claim you link to. The data given at those links is inadequate – no levels for Sat/Sun and no info on what was happening in the catchment – which definitely was not steady rain. Without that info, and the legislative framework under which SEQ Water operates criticisms are very speculative.
Chris O’Neill, my understanding is that the self actuating uncontrolled release of water at the Wivenhoe dam did not occur and has bugger all to do with staffing levels.
The massive physical and technological developments occurred in the industrial revolution when population was much smaller.
Humanity has not chosen massive population, this is an unplanned consequence of other activity. When it gets to the stage where extra population costs too much, humanity can, does, and should choose otherwise.
The world has less need now for “massive physical and technological developments” than the glaring need for a better distribution of the current level of development. This sharing is best facilitated in the absence of population pressures.
@Chris O’Neill
Irony Alert On. It is always easier to manage a complex evolving situation with the benefit of hindsight. Irony Alert Off.
I concur with gregh. A lot of data and hydrological expertise in interpreting that data would be required to assess the management of Wivenhoe levels during the last month. I suspect SEQ Water would run river flow and height modelling programs continually as an aid to managing releases. The entire Brisbane-Bremer system and catchment rain events over time is a complex entity to model and make predictions for in hydrological terms.
By all means, do a considered post-event review. However, I doubt that an alarmist journalist’s back of the envelope assessment amounts to anything.
Ikonoclast, the authorities know what they are doing at the Wivenhoe dam for the volume of water released was a controlled event.
Perhaps Pr Q needs to establish a thread for Water conspiracy theory after the flood.
Perhaps Pr Q needs to establish a thread for Water conspiracy theory after the flood.
@Ikonoclast
From the interviews I heard on the radio – until we lost power – I was very impressed with the various people involved in trying to manage the flood.
It struck me that politics (broadly construed) was taken out of the management as the situation developed so quickly and was of such a scale that people who knew what they were doing were acting without a great deal of external interference.
Pointing fingers makes sense where foresight into likely consequences, upon taking certain actions, is available. Not much sense in it when an event ultimately comes down to luck of the draw, eg available meteorological forecasts and juggling of controlled dam releases. Imagine the uproar if a flood event was caused by releasing so much water that a downstream storm combined to flood out some houses somewhere? But then, holding onto the dam release for just one more day, hoping storms are going to fade before the dam is full?
On the contrary I think people in this line of work deserve a round of applause. Governments both state and federal, on the other hand…probably need to consider how new towns and cities are planned for, and may be encouraged to develop away from the high risk areas. Oh, our manufacturing jobs went off-shore, you say? Bum, it will be hard to build a new town if there is no reason to settle there 😦
At the least though, town planners should be subject to jeers for allowing/encouraging development along the big Murray. Leave that ground for parks and the like, or even farming, but keep the houses off.
First, I am sorry if this offends your ban on AGW, but I do not know what that is: anthropogenic global warming, anti global warming, accelerated global warming? It’s probably not the on line magazine A Girls World.
I disagree with your 1st dot point on two grounds. Rainfall in not increased over all of Australia – the southern half of WA has considerably less rain than it had 40 years ago, with the decrease said to have started around 1971. Second the history is important. As I mention in my admittedly not widely read blog, La Nina is not enough to explain the current summer Australian rain pattern. And parts of Queensland have had floods for longer than we have recorded their history.
It may be that better use of current and perhaps future dams will decrease the severity of future floods. But, “It may be” is not good enough. We need a non-political scientific study of past, present and future rainfall and weather patterns as part of the beginning of a flood mitigation study. The outcome might be more dams, but it could also be water directing channels or even suggesting that some parts of Queensland should not be sites for permanent housing.
Regrettably, the study is required soonest, despite the obvious urgency of attending to the personal and public tragedies that these floods have caused. Rebuilding a house so that it can be flooded next year still without insurance is not the best long term way to handle tragedy.
@David Horton
Of course, the big winners to date have been property developers, who build in areas that should be excluded from development. They construct their buildings, sell them on and walk away, carrying none of the risk.
Regulation hasn’t been working too well (developer donations at risk?). Perhaps the likes of Nearmap will help people make an informed property purchase. As an alternative to regulating the construction, I wonder how feasible it might be to make it a condition of the land title that flood insurance be maintained for any building on the site?
@Peter
Others would say we only need a non-denialist reading of available scientific studies of past, present and future rainfall and weather patterns.
@Michael of Summerhill
The self actuating uncontrolled release of water occurs at maximum dam level to protect the dam. This has nothing directly to do with releases to preserve flood mitigation capacity which are supposed to begin when the level exceeds 100% of water supply capacity. These releases are manually controlled, as far as I know.
I’m amazed how easily people misunderstand the issues involved.
@Chris Warren
To amplify a little. The South WA decrease rainfall pattern has persisted for 40 yrs and has occurred with La Nina and El Nino and neither. Furthermore there is no logical reason to suppose that the weather there should be affected by La Nina cycles. The cold fronts are simply passing further south and so there is less rainfall over the land. The 1974 and the current Qld floods can be associated with La Nina. However there have been floods with no La Nina and there have been La Nina events with no floods. An explanation in addition to La Nina is thus required to explain flooding and certainly to predict it.
@gregh
I like the irony, “no levels for Sat/Sun”. This wouldn’t have anything to do with them not working and managing the dam release on Sat/Sun, would it? That was the whole point, they set the release rate on Friday, went home for the week-end, came in on Monday morning and thought “Oh sh!t”.
@Chris O’Neill
How do you know that Chris?
@Chris O’Neill
one of the issues they were concerned about was the triggering of the auto-release, which apparently would limit their ability to control release for mitigation. The chap I heard speaking about this at the time was actually more than ‘concerned’
They could have released a lot of water without even causing a minor flood level in Brisbane. The guage at Jindaleee was below minor flood level until 1 pm on Tuesday the 11th and below moderate flood level until 7 pm. So they could have had higher releases at Wivenhoe right through the weekend until midday on Monday the 10th without causing any more than minor flooding on the Brisbane River in Brisbane. Of course, if you’re not thinking about these issues until after 9 am on Monday morning then you’re probably already in deep doo-doo and there’s very little you can do about it. If they really did set-and-forget the dam release for the whole weekend then they are guilty of massive negligence.
Chris O’Neill, Gregh is wright @ 44 for when the self actuating gates open, the authorities could not control the uncontrollable volume of water flowing out of the dam.
@gregh
I WANT to know and I should think a lot of other people want to know too.
@gregh
You’re still missing the point. They should have been releasing much more water LONG before the auto-release had any chance of being triggered.
@Chris O’Neill
That’s quite a backpedal from your earlier statement.
“…they set the release rate on Friday, went home for the week-end, came in on Monday morning and thought “Oh sh!t”.
@Chris O’Neill
great and incredibly unimpressive hindsight