Regular ACM contributor Bruce (brc) wrote a lengthy comment on an earlier item which I believe rightly deserves a post of its own. I would like to thank Bruce for his thorough and down to earth assessment of the current Queensland floods which commentators on all sides would do well to imitate:
Look, as a 3rd generation lifelong South East Queensland (“SEQ”) resident, all this world wide attention and theories are starting to irk me as talking heads start to spout off things of which they appear to have little understanding. SEQ (and Queensland in general) is periodically subject to intense widespread rain events: 1893, 1974, 2011. They happen. Even smaller intense rain events occur at least once a decade. The 1893 floods were larger, and peaked on 3 separate occasions. Does anyone care to tell me how AGW could have done that, given that horseback was the primary transportation method at the time, and electricity was something played with in laboratories?
If anything, the lower levels in 1974 and 2011 is proof that AGW makes the flooding less worse (I say with tongue in cheek). There’s also a popular meme going around (James Delingpole and Andrew Bolt) that somehow green interfering caused the death and destruction. Nothing could be further from the truth. And believe me, I love a good outing of ridiculous green policy as much as the next person.
Here are the facts:
- The majority of loss of life was caused by flash-flooding in and around Toowoomba (700m above sea level) and the Lockyer valley below the Toowoomba range. The streams that caused the devastation in Toowoomba are normally babbling brooks one can leap with a vigorous jump. While some warning may have helped, many deaths were caused by people undertaking risky actions like trying to drive across flooded bridges.
- The scrapped Traveston Crossing dam project on the Mary river would not have saved Gympie from flooding. It would have been 100% full (like every other dam in the region) prior to the large rain events – it has been raining steadily for two months. In any case, it was the residents of Gympie that campaigned the most against the dam. Not because of lungfish (the figleaf that the environment minister used) but because it was a bad idea. A flat alluvial sandy plain is not the ideal location for a dam. It would have been wide and shallow on porous soil. And it would have subsumed a huge area of productive farmland. It was correct for the dam to be scrapped, and many engineers publicly stated this. That it was scrapped under environmental reasons was just the out for an embarrassed Federal government saddled with the plans after the former premier announced it to save his political hide (Brisbane was under severe water restrictions at the time) but then scarpered anyway. It was chosen because the area had never, and would never, vote for Labor anyway, so it was the best place to put it, safely away from Brisbane voters. It would have been full, and would not have saved Gympie from flooding. And the townspeople in Gympie are used to flooding anyway, and go about moving out of the way with a cheery disposition.
- Wivenhoe dam – conceived and built after the 1974 floods – has done a very good job in extremely difficult circumstances. It has managed to keep the peak level of floods 1m lower than predicted, by delicately balancing the inflows and outflows and timing with the low tide in the Brisbane river. It was already at 150% (and releasing continually, as it has been for months) when this large rainfall event hit. SEQ Water are to be commended with the way they handled this, with the Dam balanced within 1m of the peak level allowable before dam-protection levees give way to protect the wall (with devastating consequences for those downstream).
It’s difficult for people who don’t live in Queensland to understand the volumes of water we’re talking about here. This is not some drizzling Victorian rain or misty English weather. This is a proper, tropical summer monsoon rainfall a bit further south than it normally is. The written history of Queensland is only about 200 years long, but it is peppered with tales of huge floods that astound new observers. People see the 1974 markers on buildings around Brisbane and think it can’t possibly have happened. The puny infrastructure put in the way of these periodic deluges is nothing compared with the water volumes. It will happen again, at least once per lifetime of the average person. There’s nothing that can be done. After all, it’s just weather.
Simon – thanks for elevating my comment to a post, I hope it gives others some insight to the history of QLD. Interested people might like to check some interesting links available:
http://www.seqwater.com/public/dam-levels
This page shows the historical (and current) dam levels. You can used the widget at the bottom to show the historical levels for different dams. This page will show how Wivenhoe was frequently released back to 100% capacity (the water storage capacity) but, from about the 6th January onwards, the inflows were much greater than the outflows (releases) so the dam level climbed sharply to the point where they had to go to full release to keep the dam mitigating as much as possible whilst protecting the integrity of the Dam itself. The peak was at 190%. This page also shows how every other dam in the region was at 100% prior to the large rainfall event that caused the flooding, so no new Dams would have prevented the flooding unless they were of the mitigation type of Wivenhoe, which none of the planned dams have been.
For QLD flood history, take a look at this link:
http://www.bom.gov.au/hydro/flood/qld/fld_history/brisbane_history.shtml
The BOM graph shows quite clearly how we are actually in a time of lower and less frequent floods than in the period from 1850-1900, which would have been an awful time to have riverfront property. This is plenty enough evidence to break the assertion that AGW will cause larger flooding, even if on a less frequent basis. You can look at the Bremer R (Ipswich) for confirmation – there is no flood mitigation on the Bremer River.
Great post Bruce, from another 3rd generation person from Brisbane. After hearing what is coming to light in the Lockyer Valley I don’t think stupidity had much to do with the loss of life. Many of those people interviewed are lucky to be alive with quick thinking, bravery and modern technology aiding their survival.