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multiweb
06-01-2011, 03:49 PM
I don't know much about QLD geographically, been to brisbane a couple of time and drove through to northern NSW, SE QLD on the way to Fraser Island. Everytime there's more than usual rainfall we hear that a lot of people get flooded up there. It's all over the news. Why is that? I mean, has it always been this way? Aren't there any catchment areas, failsafe across the main rivers or creeks that potentially can become dangerous? Is that in planning? Just wondering why so many people are losing their homes and everything everytime this happens?

Davros
06-01-2011, 04:44 PM
Most large urban areas in Qld are situated along rivers. The rivers have always flooded seasonally and floodplain areas were left for this. Houses in affected areas were also built on stumps in days gone by. Because there has been drought for so long some councils have become blase in recent times and allowed development of flood plain areas. Coupled with this councils were making it very difficult to obtain planning permission for stumped houses and a lot of building in these areas has been of the cheap, box house on a slab style. Not really suitable when a metre and a half of water is flowing through it.
These are some reasons but it is wider ranging to the point that deforestation has removed some of the mitigation effects as well.
In short i imagine it may become a lesson relearned. :sadeyes::sadeyes:

[1ponders]
06-01-2011, 04:50 PM
It makes it easier to understand Marc when you realize that not just Qld but the whole of central Australia was once an inland sea. Its pretty damn flat out there. It takes water a long time to get anywhere out there and the catchment areas are enormous. Water starts to become its own damn wall and keeps on backin' up.

As for along the coast, yes well we will build along rivers and flood plains

Davros
06-01-2011, 05:37 PM
Should also mention that one place in Qld had over 12 meters of rain last year...............that doesn't help.

mithrandir
06-01-2011, 05:51 PM
Marc,

They were saying on ABC radio this morning that the flood water in the Qld rivers west of the Great Dividing Range would take 6 months to flow down to the mouth of the Murray River in SA. That gives you some idea of how flat it is.

With Sydney property values in mind, I'm waiting for water views at home. It would only take sea level to rise about 100 metres.

Andrew

multiweb
06-01-2011, 07:43 PM
Sounds like there's no easy solution then but it's still an awful lot of loss and harm to all the poor buggers affected. Planning catchments and embakments is not rocket science and might help slowing the water rushing in populated area. It's common practice to build catchments spread around let's say every 50km along a known stream or corridor so you have some kind of buffer(s) when the rush comes on. Somebody must have a good idea what the terrain is geologically so I would have thought this was being taken care of or in the process of. I hear you about the councils being lenient. Same thing happens in every country. People 'forget' and allow to build in places that used to be river beds until the next big rain. In Hoxton park there is a creek and the whole industrial area that developed there is in a massive flood zone. I know coz my father in law told me once "I used to go swimming right here" and we were queuing in the local KFC. I hear we've been giving millions to indonesia to help them reduce their carbon footprint. Maybe we should take care of our domestic issues first in QLD and do something about it. At least minimize the impact on people.

Davros
06-01-2011, 07:50 PM
I think that one of the reasons embankments are not used is that our rivers are either in deep gullies or dry when not in flood. Usually you go over a bridge and the river may be 10's of meters below but in flood the massive amounts of water moving breaks the banks onto the low lying land. It takes a huge amount of water to get the rivers out of their banks but thats what happens in this sort of event.