Brisbane floods: before and after
abc.net.au
abc.net.au
One thing I will never forget though. The smell.
(But congrats for getting out there - you have the support of those of us in the other states.)
You can also help, interstate, by donating money. They will need it.
Still not allowed back into work though :\
"The team encourages everyone to still come to Brisbane and support local business and the community - we need your support!"
After having been through the after-effects of an earthquake where I live it's been clear to see the difference it makes for businesses that can open to have custom.
That said, the Wivenhoe in this case did precisely what it was meant to do, and those who operated it did an admirable job under extremely trying circumstances, IMHO. It simply wasn't designed to cope with the volumes of rainfall that occurred, afaict.
I hope the forthcoming inquiry will not focus so much on the smaller-scale "tactical" decisions that led up to the flooding (it will be news to nobody if it turns out some mistakes were made: I'm sure there were), but more on the state's water management strategy as a whole. Unfortunately the news reporting I've seen so far has already tended towards the former.
It's water management strategy that has failed SE Queensland twice in the last few years: first when the water nearly ran out after the drought, and now only two years later there's too much water by half. Neither drought nor flood are strangers to Australia, so half-arsed measures and excuses should not cut it for anybody. Increasingly unstable weather conditions caused by climate change make it even more urgent that we get this right.
Is this an event that could have been prevented or is this a 1000 year flood?
shock jocks will blame the greens "for not letting us build more dams" or some other rubbish.
greens (like me) will blame poor planning for building cities and major infrastructure on known flood plains.
Seriously though, to the extent that there's fingers to be pointed they should be pointed at the folks in charge of the Wivenhoe Dam. But hey, I'm not a dam engineer, so maybe we really do need a second dam.
edit: for a positive comparison checkout south bank http://www.nearmap.com/?ll=-27.478211,153.023704&z=18...
edit2: another example of green belts along rivers is Curitiba in southern Brasil see: http://maps.google.com/?ie=UTF8&ll=-25.45894,-49.191552&... and http://en.wikipedia.org/wiki/Curitiba#Hydrography_and_Pluvio...
amazing shit you can do when you run public debt at close to 100% of GDP :)
I'm a big believer that Australian cities should be bearing this in mind and building up rather than out.
These people know they live in a flood zone. There are flood markers all over the place and every property purchase inclues a 1974 flood report as to the level of flooding in the particular property. People choose to live in these place of their own free will in the full knowledge the river might one day come and flood them.
So a wide green belt along the river might be a good idea. But it's also completely impractical and only good as a theoretical talking point.
IANAL, but as I recall, the guarantee that forced acquisition occur on just terms only binds the Commonwealth, not the states. Queensland may not have just-terms laws, and even if they do, Parliament would be able to suspend them.
So they only way to resume the properties and provide a benign area for flooding is to either (a) borrow or tax a lot of money for the acquisition or (b) suspend the laws and steal the properties from their owners by means of modified legislation or other force.
I'm not saying that forced property acquisition should never occur, clearly there needs to be cases where this happens ('The Castle' notwithstanding). But to forcefully acquire all the property along the Brisbane river? Another flood mitigation Dam would be a lot cheaper and keep a lot more people happy, and provide more water for droughts. Queensland is still woefully under-equipped for long dry periods. Wivenhoe was designed to mitigate flood waters and guarantee supply until 2000. SEQ needs another large dam.
What you say is true of acquisitions made by the Commonwealth. The Federal Constitution makes that explicit guarantee (Section 51(xxxi)) -- incidentally the High Court have taken the view that "just terms" does not necessarily mean "at market rates". My parents got diddly poop for land compulsorily acquired by the Whitlam Government near Darwin.
But the states are not bound by that guarantee and each State Constitution may or may not have requirements for just terms acquisition by the states. Moreover, State constitutions are generally amendable by State Parliaments without requiring a referendum, making them much less robust to policy pressure than the Federal Constitution.
If it so happens to be that Queensland's "just terms" rules are in an amendable constitution or are an Act of Parliament, then there would be no legal barrier to the Parliament removing or drastically reducing compensation for compulsory acquisition of land.
However I suspect land along the Brisbane river will not be acquired because of the politically poisonous nature of compulsory acquisitions generally.
"These people know they live in a flood zone. [...] People choose to live in these place of their own free will in the full knowledge the river might one day come and flood them."
Doesn't this end up being the usual privatize the profit, socialize the risk scheme? People enjoy their property on flood-free years (which I understand to be most of them). In a flood, the society sticks together, volunteers, the government steps in and helps out the flooded areas. People who live above the flood level, who might have chosen to do so consciously because of the flood level, get little reward for their risk avoidance.
I don't mean to sound heartless and I am sure it is horrible to have your house under water -- but isn't this an issue at the end of the day? Is there a factor I am not aware of? Is there an overall shortage of suitable, natural-disaster-proof land? Do you get flood insurance and pay back for the help received?
>Doesn't this end up being the usual privatize the profit, socialize the risk scheme?
In short, there's very few locations which don't have advantages of a greater public pool of funds to assist in disaster.
You might say this but I'll counter by saying that all residents of San Francisco are privatising the benefits of living in such a nice city, while greater California and the USA are socialising their risk of living in an earthquake prone area. The same goes for tornado country, or most of florida with Hurricanes, or wherever, really.
So while you can probably argue the technical merits of such a statement it quickly can be applied to just about anyone, anywhere, and starts to look absurd.
I would object if people living in flood zones were automatically provided with government funds to rebuild. While the government might donate money to the general cause of rebuilding (much of which goes to hardship funding) they don't directly underwrite private property. So the person with the most risk is the one living next to the river. As long as they don't expect or are promised help, then you're not socialising the risk. If people volunteer help after the fact, that's a different thing.
(For O/S readers, the leader of the Greens party claimed that "The Coal Industry should have to pay for the cleanup as it was caused by climate change, which is their fault" (Paraphrased). This is not only unproven, it's also a cop-out... PEOPLE used that coal Bob, they're to blame as well if we believe your causality logic. It's a good thing there were no floods before this year, and certainly none in the 19th century to disprove your theory that natural disasters only happen to naughty planets whose inhabitants mine coal)
If I was a supporter of Bob Brown I would be embarassed by this particular outburst.
I'm willing to accept that. But then how do we know that it wasn't acting to give us less rain on this particular occasion? How do we know that climate change didn't save us from an even worse flood?
A scientific theory has to have a hypothesis (human caused emissions of gases cause the globe to warm in a significant way) and a null hypothesis (human caused emissiosn of gases do not cause the globe to warm in a significant way). No arguments there, that's not controversial.
However, for a theory to be scientific, they have to be falsifiable. That is, there has to be a way of proving them false. But nowadays Anthropogenic Global Warming, now packaged into the catch-all Climate Change, and has been linked with these following items: more droughts, more rain, less snow, more snow, higher temperatures and lower temperatures. As every single type of weather pattern or climate outcome is now predicted by the theory, and as such it cannot be falsified. It's not a scientific theory anymore in that case. It's morphed from a scientific theory (more GHG makes the global temperature go up) into a belief system (any type of human-caused emissions causes bad weather somewhere). It's commonplace for media and activists to now link any weather outside of normal benign conditions with 'climate change'.
Normal or pleasant weather (such as pleasant summers or mild winters) are never linked with climate change - only adverse weather.
Hence Bob Brown has linked both heatwaves and bushfires and cool temperatures and flooding with climate change. Because every type of weather related event now proves the theory, there are none that disprove it.
The current weather conditions in Australia are well within historic recorded variability, and Australia's climate record is pretty short. Climate change is meant to have started either in 1850 or 1940, depending on who you listen to. But in many cases, more extreme weather was recorded prior to these dates than is found now.
But climate change has stopped being a scientific theory and now is a politicised quasi religion for some. That's a shame because researching and undestanding the climate is very important for the resource dependent world we live in. But research cannot go forwards when it is viewed through the prism of a bad theory, in the same way the luminifurous ether had to be discarded to understand light.
And for anyone who doesn't agree with me, I ask this question : what would it take for you to believe the theory has been falsified?
Liberals regain power? "Global Warming".
Ice-cream melts when it's left on the counter? "Global Warming".
Bob Brown is asked to step down as leader of the Greens? "Global Warming".
Your policy response, which can be paraphrased as 'don't build dams, move major cities' is idealogically warped and just wishful thinking. You would find it hard outside of your peer group to find anyone to take you seriously.
The cities are where they are. It's not a surprise that Brisbane and Ipswich floods - the very first parts of written QLD history contain stories of immense flooding events.
More flood mitigation via Dams is the only sensible and possible response. More dams also has the side effect of more water supplies and possibly more hydro-electric power.
I could be wrong, but I think he's suggesting not building on the areas of the city which form the flood plain, not the whole city.
We have an accurate record of which areas of the City were flooded in 1974. The areas that flooded recently are a subset of those areas. People were allowed to build in these areas because the Dam was supposed to have mitigated the risk. We could have kept zoning plans in place to deter building in these areas and still had a vibrant city built up around them. More river-front parkland to boot!
As I've already stated, if you want to clear the city from the low-lying areas, you'll have to forcibly acquire a large amount of private property, which is either an expensive (if the law is followed) route, or a suspension of the current law. So suggesting the low lying areas be forcibly cleared is clearly unworkable. And it involves acquiring and demolishing the majority of the CBD. If you think that is even remotely possible then I've got the Story Bridge to sell you.
Everyone who purchases property in Brisbane is well aware of the 1974 floods. I know, because I purchased a property knowing full well it could be flooded one day as it was in 1974. And last week it was. But I'm not about to sell it or have the government confiscate it because it gets flooded once every 40 years.
About the best thing that could happen is something along the lines of a) new developments must have critical infrastructure (electrical circuits etc) about the 100-year flood leve b) flood prone suburbs could have prominent markers, such as bands around power poles to remind people of previous flood heights. There's a popular one in the Breakfast Creek Hotel. c) new housing in flood zones could have a mandate not to use water soluble materials such as plasterboard in lower levels, and could be mandated to have the main living area above flood height. People with older houses often came out with no problems because the old houses were built with floods in mind.
This idea of avoiding flood risk by avoiding waterfront areas is silly. By the same token, all residents should abandon Cairns and Townsville because of the cyclone risk. And cyclones in the north happen far more frequently, and with more devastation than Brisbane floods.
In the Netherlands where I live, dams are combined with controlled flooding areas. The dams should hold most of the time, but the system is designed in such a way that once in 20-50 years when there is too much water it can be directed to low value areas like farm fields.
That's logical to an engineer, but it takes serious political courage to build a dam in the middle of an area where there is no water to account for a once in 50 year event, and even more courage to declare one side of that dam as "lower value". It makes economic sense though, 10 meter high dams are very expensive (and ugly), more expensive than rebuilding a few houses every generation.
The largest Dam servicing Brisbane has a total capacity of 220% - that being 100% is the 'normal' water storage level, the rest is for flood mitigation. So the Dam can temporarily hold more than double its usual capacity. Elsewhere in this topic you'll see people discussing whether that flood mitigation capacity was used correctly, and only time and investigation will tell. I would assume any new Dams planned would also incorporate a flood mitigation feature, particularly after this last flood.
The population density outside of Brisbane drops very low, very quickly. It's nothing like the Netherlands. Australia has one of the lowest population densities in the world, whereas I think the Netherlands has one of the highest.
There are a few scammers rightfully copping it, but it's been a pretty galvanising event in Australia.
Generally they are led by respected judges with technical experts in support. So sweeping are their powers that they are only ever appointed in the most extreme situations, such as massive natural disasters (Victoria bushfires, now Queensland floods) or revelations of severe maladministration (corruption in Queensland and NSW police forces).
The Royal Commission into the Black Saturday bushfires in Victoria did point to individual as well as systemic failures. Some of these individuals were seen as being close enough to the government that the Royal Commission's findings contributed to the downfall of the government at a subsequent election.
- Campbell Newman, Lord Mayor of Brisbane - Anna Bligh, Premier of Queensland - Julia Gillard, Prime Minister of Australia
I think it's pretty unlikely that you could pin the blame on any of them and they all responded well once the crisis happened.
The operating rules for the Wivenhoe dam (which is supposed to mitigate this kind of thing) decide how much water can be released and when, and that is set at the state level (i.e. by Queensland state government), so probably Anna Bligh is the easiest target in that respect.
I saw an official describe the dam operating rules as "conservative", but I'm not sure in which direction they are conservative - in the direction of minimising releases or minimising risk of overflow.
Australians also always have bushfire risk - it is just part and parcel of the native vegetation, and fire mitigation techniques only go so far (see the bad Canberra fires of 2003 or the disastrous Victorian fires in 2009).
1. The Australian media doesn't run on a 24-hour "outrage" cycle. We don't have any way to blame this on some targeted political figure (though certainly political figures have come in for some criticism). People will get blamed (particularly those who were in charge of the dam that was supposed to prevent this from happening again) but it'll happen slowly and in a controlled manner, not in a rapid flurry of 24-hour-news-station activity. We have a procedure for finger-pointing, and it's called a Royal Commission... we'll spend a year investigating and holding hearings and then eventually find the correct people at whom to tut-tut.
2. The death toll is relatively low. Very low in Brisbane itself (where the rise of the floodwaters was gentle) and a mere dozen or so in other parts of the state (where flash floods did occur). Sad and all that, but still on a relatively small scale.
3. No breakdown of order. Partly because a river flood is nothing like a hurricane (the city itself wasn't cut off, and if you're in an affected area you can walk five blocks to an unaffected area) and partly because of the different quality of people in the two cities.
4. New Orleans already had serious problems (poverty, race relations) which were only exacerbated. Brisbane was a pretty nice place, and it's still a pretty nice place (except for the parts which are now ruined).
In answer to your question, though, this isn't a once-in-1000-year flood... more a twice-a-century sort of flood... we had floods in the 1890s and again in 1974. The Wivenhoe Dam was constructed to prevent the 1974 flood from ever happening again. It didn't work, partly because the folks in charge of operating the dam didn't start releasing water until it was too late... which was itself partly because they've been worrying for most of the last decade about running out of water and forgot that too much water is also a problem.
There's a reason why the architectural style known as a "Queenslander" is a house on stilts though -- Queensland is not a stranger to floods.
As for the dam management, the principles of operation are deliberately not subject to political whim, so were considered appropriate at the time. There was also more water then in 1974 AND a king tide, so there are some mitigating factors. Only the full inquest will really tell for sure.
Wivenhoe dam[1] did work as flood mitigation, but there were concerns during the flood as the water level was spiking quickly towards maximum storage[2], so some water was being let out (apparently about half of what was going in).
If the dam did get to full capacity its automatic system would have fully opened the flood gates, potentially making the flood situation quickly worsen even more.
[1] http://www.seqwater.com.au/public/catch-store-treat/dams/wiv...
[2] http://www.seqwater.com.au/public/dam-levels
See the interactive graph at the bottom of the page, you can choose to see only Wivenhoe's storage level history. Its level is almost back to 100% which is the normal water storage level, not the full flood mitigation level.
We do have bloggers who don't mind slipping the boot into each other. Two sites I host (catallaxyfiles.com and larvatusprodeo.net) have been sniping from both sides of the standard political divide.
Actually the idea of a Royal Commission is just part of a smaller idea missing from US governance: the idea that an organ of the government can be completely non-partisan. Royal Commissions are instigated by politicians, but they're expected to exist far above the fray of ordinary politics; certainly I've never heard of any accusations that a Royal Commission is biased one way or the other.
Other examples of entities which manage in Australia to escape the partisanship which dominates them in the US are the High (Supreme) Court and the process for redrawing the boundaries of electoral districts.
For this American, that sounds like not being allowed to talk about their bias. I would guess that many Americans do not believe in an unbiased group of any sort, at any level.
Yes, that's kindof what I was trying to say. And I think to some extent it's a bit of a self-fulfilling prophecy. Of course people are only human and have their biases, but if you create a social expectation that they'll be unbiased (and combine this with choosing the best people for the job -- old judges with nothing in particular to gain or lose and a well-earned reputation for impartiality) then they will be as unbiased as humanly possible.
The "Royal" in the title is no accident, though -- the traditions of the Commonwealth countries dictate that the Crown is above all politics, so anything expected to be above politics is always given a direct symbolic link to the monarchy. In the US there is no such thing and the highest power in the land is just another damn politician.
One might, perhaps going only a little too far, wonder whether the American political need to constantly invoke God comes from not having a Queen instead.
Yes, but they are rarely used, for two reasons.
1. They resemble the Star Chamber in their powers and setup. The Common Law has an unflattering cultural memory of this time in its history.
2. Their independence makes them dangerous to the commissioning government. For political reasons various watered-down sorts of inquiry are preferred instead.
> Royal Commissions are instigated by politicians, but they're expected to exist far above the fray of ordinary politics; certainly I've never heard of any accusations that a Royal Commission is biased one way or the other.
The Costigan Commission has been accused of bias, or at least going outside its terms of reference.
> Other examples of entities which manage in Australia to escape the partisanship which dominates them in the US are the High (Supreme) Court and the process for redrawing the boundaries of electoral districts.
I'm not sure why the HCA has avoided such a divisive culture as in the US. Probably because our jurisprudence has evolved in a quite different direction from the USA's in terms of constitutional interpretation. Simplifying grossly, the US model is "realist", taking the view that all judges are biased and that policy consideration affects judicial decisions; the Australian model is more "legalist", in that every attempt is made to ignore the policy implications and attend only to the law.
Of course in both countries the debate is far more complex and nuanced than that; but in Australia our judges have developed a theory of interpretation that blends legalism[1] and a general rejection of originalism/purposefulness[2]. This latter strand has caused the original design of the federation to be steadily turned inside out.
As for electoral boundaries, yes, having independent electoral commissions is a huge boon to our country and something that should be more widely replicated. In terms of electoral systems Australia is a world leader in many areas.
[1] Justice Sir Owen Dixon championed this view and shaped the post-50s court. He said upon becoming Chief Justice: "Close adherence to legal reasoning is the only way to maintain the confidence of all parties in federal conflicts. It may be that the Court is thought to be excessively legalistic. I should be sorry to think that it is anything else. There is no other safe guide to judicial decisions in great conflicts than a strict and complete legalism". His thinking in this case was shaped by the previous appointment of politicians to the High Court.
[2] Justice Isaacs introduced this mode of reasoning in the famous Engineers case.
I suspect, that much of the flood waters came from the Lockyer Creek (the waterway that was the source of those horrendous videos from Toowoomba) - which actually feed into the brisbane river _downstream_ of Wivenhoe dam, meaning that the dam couldn't stop a large chunk of the flood water from entering the Brisbane river. See this map here: http://maps.google.com.au/?ie=UTF8&ll=-27.409109,152.603...
So maybe part of the blame should be placed on the Dam designers... But perhaps other topological constraints prevented the Dam from being located further downstream?
Lots of pieces to the puzzle and I don't think it is as simple as just the dam operators waiting till it was too late..
I certainly hope that the answer to "Why was Brisbane flooded" turns out to be primarily "Mother Nature is a bitch" rather than "Random public servant Joe Bloggs screwed up big time".
What the hell is that supposed to mean?
The last flood in 1974 was slightly worse and there have been worse ones in 1893 and 1841. So I guess you could say we are a bit prone to flooding. A damn was built in 1984 to mitigate the effects but it was close to full due to exceptional rain leading up to the main deluge. The damn still helped considerably and allowed them to block some water flow at high tide, but there is some suggestion that more proactive emptying earlier would have helped.
At the very least it let them control the flow a little bit so we didn't just get hit by a massive wave all in one go.
This is part of what the Royal Commission will sort out.
I expect the outcome will be a new operating manual for the Dam, and more frequent minor flooding in keeping with an aggressive plan of keeping the dam at 100% (water storage) level, leaving the extra 100% of flood mitigation level free as soon as possible.
Another possible outcome may be more dams on some of the other river systems, such as the Bremer river.
I tried to get onto the Moreton shire council to find a road closures list, and was faced with a downloadable MS Word document. There's the two extremes for you.
One thing that governments everywhere should learn from this is that maintaining and using Twitter and Facebook from established, trusted accounts is a very good way of getting information out there. Even if only a tiny fraction of the population are subscribed, they can quickly disseminate information to neighbours and family members.
I think the BOM should look into it.
After the 74 floods, we built a dam (Wivanhoe) to prevent it from happening again, and yet we came not far from the 74 levels - amazing to think what would have happened without that dam!
In reality the PM who deposed him was in town, and I think he felt compelled to get some air-time to compete, seeing as he was the local boy and all. No love lost between those two.
On the other hand, the way people behave in crisis situations is largely dependent upon the way they see prominent people behaving. If prominent people are out there volunteering and helping out their neighbours then it makes it more likely that other folks will too. Mr Rudd is probably the most prominent Brisbanite at the moment (possible exceptions of the Premier and the Lord Mayor who were busy with their actual duties) so by helping out his neighbours (with cameras present) he can do a lot to set the tone for the behaviour of Brisbanites during and after the disaster (which I must say has been pretty much exemplary).
I'd never vote for Kevin Rudd, but I'm perfectly prepared to give him due credit for doing the right thing. (Unless of course it turns out that he only helped out for five minutes and stopped as soon as the cameras left).
I'm far more impressed with Rudd getting his hands dirty than others hiding in Canberra trying to score points by press release.
As an ex-pat aussie looking at this from abroad, at appears as if various levels of Australian government are pulling together and focusing on clean-up. In many other places, things descend into blame and confusion pretty quickly, which is what happened in the US. I'm sure Bush did care what was happening on the ground, but the confused response between the different levels of government was astounding (and surely wasn't the feds fault alone).
For all the internal complaining about who is running the show in oz at various times, the country has a healthy and functional democracy in many ways. And Queenslanders will pull through.. the state is full of tough buggers. Best wishes to all affected back home.
In fairness Katrina was a much more difficult disaster to deal with than the flood. The flood required small-scale evacuations, while Katrina required the evacuation of an entire city. There's always going to be chaos when you try to evacuate an entire metropolitan area within 48 hours... the manpower and infrastructure to do that kind of thing just doesn't exist.
And that's before you consider that there was a storm as well as a flood.
I guess all reminders of our planet's volatility no matter where we choose to settle.
Compare to Bligh in QLD, who was doing two-hourly media stops packed with information, keeping people abreast of what was going on. The second day of the recovery they realised that they had so much volunteerism that they had to tap it - and there's aerial footage of volunteer centers with queues literally over a kilometer long. Compare to Katrina when the feds had no idea what was going on and where they also copped flak - rightly or wrongly - for not letting volunteers help in a timely manner
Even on the information front alone, if people know what's going on, they feel in control of the situation as the 'what ifs' are minimised. QLD flood victims felt acknowledged, Katrina victims felt abandoned.
Katrina was indeed much worse than the QLD floods, but that doesn't absolve a politician of having to provide good leadership.
Most people in Australia know of the extremes of the place. So major fires, droughts, floods, storms and cyclones are only a matter of when, rather than if.
It's not a 1000 year flood. These types of things happen at least once every 50 years (plus more frequent minor floods) going back about 170 years to the written history. The major dam built to mitigate (not prevent) flooding arguably might have performed better to lower the peak, but the flood event came after a month of record rainfall, and the dam operators followed the manual given to them. That might need review for future operations, but it's not like someone did something rash or stupid.
Australia is not a place of high social tension, or of high crime. Brisbane itself is a sunny, peaceful city with a normally benign river winding through the middle. When a disaster strikes, people are more likely to muck in and help out their less fortunate neighbours than to try and steal their stuff. Not that looting doesn't happen - some does, but there is plenty of incidents where citizens have interrupted looters and run them out of town.
Another feature of Brisbane flooding is that it affects rich and poor equally. Some of the most expensive houses front the river and have private pontoons (most of which are now in the ocean) - these get flooded. Some of the poorer areas are built in low-lying land, which also gets flooded. So it's not a class thing in that only the poor get affected. Some of the worst hit suburbs are also the most expensive suburbs to live.
As to why Australia tends to come together rather than fall apart - well, that would make for a fascinating social study. Personally I see it enshrined as part of the nations (and especially Queensland) culture - fair go, mateship, sticking together when the chips are down, having strength in adversity. You can probably explain as much when the most celebrated annual military parade day (Anzac day) commemorates Australia first and greatest military defeat, whereas there are no parades celebrating Australian military victories.
Or, to sum up even more succinctly, despite sharing a language and both being previous colonies, Australia and America are fundamentally different countries in many ways.
There are other parts of America where people, when disaster strikes, will start looting and setting fire to police cars.
Australia just happens to resemble the best parts of America rather than the worst parts, in this regard.
> Australia just happens to resemble the best parts of America rather than the worst parts, in this regard.
Anyone who was sensing racial overtones in the first 2 sentences pretty much has their confirmation here. I don't know if the author intended this or not but if he did have a point regarding race and/or culture to make then it should be made with more intellectual honesty and evidence/reasoning. Instead it comes of as snide at best.
(Tip for the sarcasm impaired: that's a bad joke.)
Some sea snakes (at least in Australia) are venomous. Also, snakes (including venomous ones that might normally live out of the water) can swim and in flooded regions would be forced to do just that. The red bellied black snake isn't as dangerous as the inland taipan or eastern brown, but it does like water.
Some of the most dangerous snakes in Australia always live in and near watercourses, and are usually disturbed while sunning themselves near a river when someone decides to go for a swim. The types of snakes found swimming around in the Queensland floods are not the types you want to be messing with.
Try this one on for size : http://www.snakecatchers.com.au/Red_Bellied_Black_Snake.html
I saw a 3m one of these about a week ago sunning itself next to the river near my house. And I don't live in the bush.
A brown snake in the water will climb in a house to take refuge, not to attack. they're just trying to get out of the water, just like cockroaches piling up on traffic lights.
If it's photoshopped it's pretty convincing, and if it's a big rubber crocodile then... who has a big rubber crocodile anyway?
No crocs in Brisbane. Every year is the same claims "I saw a croc!"
1. __have home on high ground__
2. see 1
3. see 1
all else is bullshit and/or out of your control (eg. level of flooding, degree of local or government competence/planning/assistance, etc.)