The Floods

[crabmeat thompson]

Wivenhoe prevented another 1974 episode.

Gee, Fong jumping to conclusions before all the facts are known. That's not like him.

what planet do u guys live on

check it on tv....the flood was just as bad....FACT

the dam failed

u can argue it stopped being worse than 74....but thats not a fact

fact is it was just nearly as bad

only more are suffering cause more houses where built ... on the promise.cause the dam stop them flooding

now....who faults that

thats the offical goverment reponse to date...and the mongs are lapping it up

On the abc they were interviewing a brisbane city hydrologist ... By his reckoning if not for Wivenhoe the Brisbane river would've peaked at around 7 metres, which would have smashed the 5.6 in 1974.

He said it was touch and go for a while there that wivenhoe was going to exceed 225% capacity, which would have been catastrophic. In which case wivenhoe would have spectacularly failed.

So Fong, while I don't disagree wivenhoe has the potential to be a balls up, for now it's a success. A 7mtr peak would have wiped out entire suburbs, not just messed them up.

[alakaboo]

only more are suffering cause more houses where built ... on the promise.cause the dam stop them flooding
now....who faults that

not to fuel the fong flames, but in this case it was labor...TQ.
in fact vowing to change the way flood zones were applied in planning was one of the foundations of the current lord mayor's election.

actually Braithy, it was touch and go whether it would get to 200%, it's almost impossible for it to get to 225, due to the emergency structures built into the dam.

[crabmeat thompson]

actually Braithy, it was touch and go whether it would get to 200%, it's almost impossible for it to get to 225, due to the emergency structures built into the dam.

Really? I'm going strictly from memory of the interview, but the hydrologist guy was saying something about the level was approaching maximum capacity, and there were meetings with the army, bligh, gillard and the wivenhoe hydrologist committee and they were deliberating releasing water from the dam, which would have resulted in further flooding, but evaded the calamity of the dam reaching capacity.

What happens if wivenhoe reaches 225%?

[mustkillmulloway]

. A 7mtr peak would have wiped out entire suburbs, not just messed them up.

thats not a fact...that didn't happen....please stick too facts

u will upset damage

if the dam was built stop a repeat 74...it has failed....because a repeat just occur

[crabmeat thompson]

. A 7mtr peak would have wiped out entire suburbs, not just messed them up.

thats not a fact...that didn't happen....please stick too facts

u will upset damage

if the dam was built stop a repeat 74...it has failed....because a repeat just occur

I think the problem is with governments making ludicrous declarations that 1974 will never happen again. Brisbane is a flood plain ... all the king's horses won't stop it from flooding if we get biblical proportions of water.

[alakaboo]

i may well be wrong, but I think he would have been talking about the level at which the first fuse plug erodes. That's a big dirt bank that is designed to wash away and form a second spillway in the event that the water level is getting too high.
It's not based strictly on a percent capacity, rather a water height at the dam wall. The important number was 75.3m, and I think it got to about 74.83, even with them dumping as much water as they could.
The plug is designed to drop it back to about 68m pretty quickly.

If it doesn't work, and the water level keeps rising rapidly enough, then I think there is another much larger section of spillway designed to give way, because the dam wall isn't designed to be overtopped. if it is, the dam wall would give way.
Not sure what that does to the water levels.

What happens if wivenhoe reaches 225%?

run and fcuken hide. it's not even worth considering.

it's rarely the weight of water that is the issue. i was talking to some people who design dams recently, and they said the problem with the water going over the top is that the stream causes such a strong vacuum effect on the downstream side of the wall that it can suck out 50 tonne blocks of concrete.
same effect that makes the shower curtain move inwards when you turn on the water...

Fong, there's an animation floating about (sorry, bad pun) from AAM, who modelled what 7m would look like in Brisbane. It's not pretty.

[crabmeat thompson]

i may well be wrong, but I think he would have been talking about the level at which the first fuse plug erodes. That's a big dirt bank that is designed to wash away and form a second spillway in the event that the water level is getting too high.
It's not based strictly on a percent capacity, rather a water height at the dam wall. The important number was 75.3m, and I think it got to about 74.83, even with them dumping as much water as they could.
The plug is designed to drop it back to about 68m pretty quickly.

If it doesn't work, and the water level keeps rising rapidly enough, then I think there is another much larger section of spillway designed to give way, because the dam wall isn't designed to be overtopped. if it is, the dam wall would give way.
Not sure what that does to the water levels.

What happens if wivenhoe reaches 225%?

run and fcuken hide. it's not even worth considering.

it's rarely the weight of water that is the issue. i was talking to some people who design dams recently, and they said the problem with the water going over the top is that the stream causes such a strong vacuum effect on the downstream side of the wall that it can suck out 50 tonne blocks of concrete.
same effect that makes the shower curtain move inwards when you turn on the water...

Fong, there's an animation floating about (sorry, bad pun) from AAM, who modelled what 7m would look like in Brisbane. It's not pretty.

Far out. That is some scary shit about wivenhoe and the intricacies which lie within. I hope SE Qld never gets enough rain for that kind of scenario.

ABC showed the 7mtre graphic for Brisbane. The hydrologist reckoned entire suburbs would have been erased from the map.

[alakaboo]

The flood modelling is up on youtube now:
http://www.youtube.com/watch?v=XKvYHUkuuLc shows 3.5 and 7m floods, this was the one on the news.
http://www.youtube.com/watch?v=QKLP-EGa ... h_response shows 5.5, which is basically what 74 was and what was predicted for 2011, but with the new buildings.

Far out. That is some scary shit about wivenhoe and the intricacies which lie within. I hope SE Qld never gets enough rain for that kind of scenario.

not even the half of it. Apparently Somerset has some structural problems, and it went to the brink too... if it went, then it cascades into Wivenhoe, the plug is breached... and for a while it was looking like that would coincide with the pulse coming down from the Lockyer.

I'm starting to wish I knew a lot less about those rivers and catchments, particularly given that most of my friends and family live downstream.

[Beanpole]

So how you going with your volunteer work for the clean up fong?
Looks like some good waves at the gold coast points.
Stupid Queenslanders working as a community to help each other out.
I wonder who those people are out there surfing at all those points?

Its quite possible it will all happen again in the next couple of months since its still the cyclone season.
One of the big pluses for the operation is that theyve got one council instead of 50.

I find it laughable that anyone would think the labor party has a franchise on stupid government and bad
planning.The whole east coast is a disaster waiting to happen due to poor planning by all governments.

Ultimately houses aren't built to the same standards as they used to be and forces of nature can always kick our collective butts anytime
the conditions are right.

I do agree Gillard remains as ordinary as I always thought she was. I also like how Abbott had one eye on the camera with every heart felt look of concern. He's a reptile and the current crisis just reveals them to be as useless as each other. Game on.
Even Julie Bishop came across as being more real than those two.

[Trev]

There were so many volunteers yesterday they had to turn some away.
And on top of that lenty didn't register, just went to a street where they knew someone and worked their way along it, helping where they could.

[Damage]

What say Germaine?

[Beanpole]

Exactly trev. Brings the community together like nothing else. The media look for negative stories or try to make up some narrative that suits their purposes but the real story is people forgetting their differences and helping each other out. Its stupid to bang on about dams and government mismanagement in the middle of a catastrophy.

My sister in laws stuck on her farm next to a tributary of the clarence river at the moment. She's okay because she's up high. Haven't heard as much about that area though.

[Cookie]

The media look for negative stories or try to make up some narrative that suits their purposes but the real story is people forgetting their differences and helping each other out. Its stupid to bang on about dams and government mismanagement in the middle of a catastrophy.

Actually there seems to be the total opposite as far as I can see. Ch 7 and 9 are all over the inspiring stories of the Brisbane cleanup.

The big issue should be the way that a regular natural event has turned into a "catastrophe". What happened in Toowoomba and the Lockyer Valley with the flash floods was a catastrophe. What happened in Brisbane and Ipswich were just floods, and nowhere near big ones. There have been six bigger floods on record since 1840.

Despite all the media banging on about the 1974 record floods, Brisbane has had at least three comparatively massive floods in 1893 and twice in the 1840s. The record is 8.53m in 1841. 8.46m in 1893. Those are the benchmarks when you start talking about 1 in 100 year floods, not 1974. There have been six bigger floods on record since 1840.

Ipswich got to 19 and a bit, well below the 20.5 that they got in the 1974 flood (despite not having Wivenhoe to help them ) and nowhere near the 25m record from 1893.

So what happens to Wivenhoe and Brisbane when they get a BIG flood or a record one?

Its the same worldwide, population pressures are forcing development into the way of potential natural disasters but a little foresight can go a long way. At least now the real estate agents won't be able to con people into paying a million for waterfront property on the Brisbane River that was supposedly flood proof.

[alakaboo]

The big issue should be the way that a regular natural event has turned into a "catastrophe".

Those are the benchmarks when you start talking about 1 in 100 year floods, not 1974.

well said.
a large part of the problem stems from the fact we don't know what a 1 in 100 yr event is for most cases, due to short records and a highly variable climate we don't understand well at all.

In that case...

a little foresight can go a long way.

At least now the real estate agents won't be able to con people into paying a million for waterfront property on the Brisbane River that was supposedly flood proof.

I wonder when we'll see the same logic applied to beachfront properties.

[crabmeat thompson]

My sister in laws stuck on her farm next to a tributary of the clarence river at the moment. She's okay because she's up high. Haven't heard as much about that area though.

Me too, up high and dry, but completely cut off. Going nuts. All my wife & kids have been eating small rations of fish fingers, bread - peanut butter, braised steak & onions for nearly a week. A neighbour bought over some chicken and sausages this morning ... So I can't wait to murder that tonight.

River has dropped bigtime o'night. Word is by Tuesday the roads will be open up and supply trucks will make their way into town. But got told to expect another few days beyond that before the shops will be able to meet demand.

Compare Bligh and Qld, where Qld have had updates and been kept significantly in the information loop and know what's going on when and where, to the clusterfcuk that Kenneally is running. The only information we've heard is what SES and neighbours pass along to us.

[Trev]

The media look for negative stories or try to make up some narrative that suits their purposes but the real story is people forgetting their differences and helping each other out. Its stupid to bang on about dams and government mismanagement in the middle of a catastrophy.

Actually there seems to be the total opposite as far as I can see. Ch 7 and 9 are all over the inspiring stories of the Brisbane cleanup.

The big issue should be the way that a regular natural event has turned into a "catastrophe". What happened in Toowoomba and the Lockyer Valley with the flash floods was a catastrophe. What happened in Brisbane and Ipswich were just floods, and nowhere near big ones. There have been six bigger floods on record since 1840.

Despite all the media banging on about the 1974 record floods, Brisbane has had at least three comparatively massive floods in 1893 and twice in the 1840s. The record is 8.53m in 1841. 8.46m in 1893. Those are the benchmarks when you start talking about 1 in 100 year floods, not 1974. There have been six bigger floods on record since 1840.

Ipswich got to 19 and a bit, well below the 20.5 that they got in the 1974 flood (despite not having Wivenhoe to help them ) and nowhere near the 25m record from 1893.

So what happens to Wivenhoe and Brisbane when they get a BIG flood or a record one?

Its the same worldwide, population pressures are forcing development into the way of potential natural disasters but a little foresight can go a long way. At least now the real estate agents won't be able to con people into paying a million for waterfront property on the Brisbane River that was supposedly flood proof.

True Cookie, there have been bigger floods but 1974 has become the benchmark because it was relatively recent and lives on in mny peoples' minds (including mine). What make this one worse than all th eothers is that probably twice as many people have been affected (which of course brings us back to the choice of land for development but that's a question for the future). Right now it's all about recovery and restoration.

[Trev]

There were so many volunteers yesterday they had to turn some away.
And on top of that lenty didn't register, just went to a street where they knew someone and worked their way along it, helping where they could.

Otherwise known as looters

You are an absolute fcukwit. Go back to NZ with your sheep and your chooks.

[alakaboo]

Compare Bligh and Qld, where Qld have had updates and been kept significantly in the information loop and know what's going on when and where, to the clusterfcuk that Kenneally is running. The only information we've heard is what SES and neighbours pass along to us.

Braithy, assume you have this already...if not there's links to most of what you want.
http://www.abc.net.au/northcoast/emergencies/?ref=nav