Floods in Australia - feedback

Discussion in 'General chat' started by Gearage, Jan 18, 2011.

  1. Gearage

    Gearage Junior Member

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    This may be a bit premature but can any of the Australian Permaculturalists give us any idea how there systems have reacted to the extreme flooding and how this has compared to the standard agricultural arrangements. I am keen to know really what levels of soil erosion where experienced and if certain living ground covers worked better than others at holding earthworks together.

    Also looking ahead, and this is probably me being optimistic, do you think these floods may be the catalyst that leads to large scale reforestation programs etc.

    Anyway my best wishes to anyone affected by these floods.

    Gearage
     
  2. adrians

    adrians Junior Member

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    we had alot of rain, water ~1m through our place, but not the terrible flooding which occured elsewhere.

    Very little erosion, since there is almost no ground that isn't either heavily mulched or covered in vegetation. erosion up to ~200mm deep occured in locations of
    1) recent earthworks - drive way etc
    2) location of recent disturbance for installing underground pipes
    3) minor scouring at spillway to dam
     
  3. Gearage

    Gearage Junior Member

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    Adrians

    Apologies , I have just written a more comprehensive reply but the computer (or I) has had a glitch of some kind, I'll try again.

    Firstly thanks for the reply. You say that you have suffered erosion on the new earthworks and where you had disturbed ground. Essentially this is so encouraging because it means that all your hard work mulching and initiating ground cover has been so worth while. I am assuming that surrounding areas that have not been setup correctly are really suffering. Do you know how much of this is being recorded because I think this kind of event if nothing else may lead to some positive feedback that could gain momentum. I mean assuming that unprepared areas suffered something like 200mm of erosion this must be devastating. Anyway I just hope that some of this data is being well recorded and that somebody in a college somewhere can collate it and make it available to the policy makers.

    Anyway thanks again for getting back to me. One more quick question. You mention your spillway suffered some scouring. Obviously moving that amount of water it was bound to suffer. Was it just hard packed earth or was there any stone etc to mitigate the effects of the flow. If it was just hard packed earth then it sounds like it had done remarkably well.

    Regards

    Gearage
     
  4. adrians

    adrians Junior Member

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    the "spillway" is only the local clayey sand, it is heavily covered in grass but has still had some minor erosion, nothing to worry about though
     
  5. Gearage

    Gearage Junior Member

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    Adrians

    Thanks for answering that. It is really encouraging to hear that your system has stood up so well and indeed that areas recently disturbed did not. Hope this is an inspiration to others as well. Good luck going forward although with good planning luck should not really come in to it much

    Regards

    Gearage
     
  6. ecodharmamark

    ecodharmamark Junior Member

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    G'day Gearage

    Welcome to the PRI Forum.

    ABC News (Australia's National News Broadcaster) has put together an interactive series of 'before' and 'during' shots of the flood as it occurred in urban and peri-urban Brisbane. It will be interesting to see if they following this series with some 'after' shots (once the flood waters have fully receded) in order to fully gauge the effects:

    Brisbane Floods: Before and After
    Brisbane Floods: Up Close

    Cheerio, Markos
     
  7. bazman

    bazman Junior Member

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    It's hard to compare my place against next door, over the last 20 days we have had 563mm of rain, we get between 1000-1500mm a year. It's bloody wet here.

    I had a blow out in one of my drains due to over grown vegetation and floating mulch blocking the drain, then pushing over the edge which then cut a bit of a hole, bugger all of a problem really.

    Swales held up really well and had a couple of times where the big swale overflowed along the entire length, interesting to note, all the water incoming into the system was crappy brown but by the time it got to the dam it was clear and water flowing out of my dam and into Lake Kurwongbah looked drinkable. Deepest water in the paddocks was 1100mm but that is water coming up from the lake.

    Food forest, Didn't lose any fruit trees and most things are enjoying the big wet, apart from my vegi gardens, I have 7 focused vegi gardens, six have been a total right offs, 95%+ die off, only the raised tank garden has done ok, but even that has been struggling. My soil here is sandy loam, and most of the time it's dry with short hits of wet weather, so in general my low style vegi gardens do really well and the rasied garden struggles compared to the others. I have had up to 2 inches of water flowing over the garden beds, I have lost most of my thick grass mulch due to faster than normal rotting, All the Biochar I have added here seems to be holding most of my soils in place which is good, but once I get a couple of dry days I have noticed the soil crusting and cracking with areas of fine sand across the surface, I have just added a ton of hardwood sawdust to my garden beds as a stop gap until I can start harvesting my local mulch again. Weeds are starting to become an issue where I have lost mulches and the grassed paths are mud tracks in places.

    I'm really happy in general with how my systems have held up under this crazy weather.

    If your interested you can see my place here.
    https://www.nearmap.com/[email protected],152.954881&ll=-27.212683,152.954881&z=20&t=h&nmd=20100907
    Here's some older pics I put together for a project showing off the gardens.
    https://www.biochar.net/kurwongbah/Kurwongbah_Overflow.html

    Baz
     
  8. Gearage

    Gearage Junior Member

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    ecodharmamark

    Thanks for putting me on to that. No doubt that the floods where serious and I think from what I have read that they are the worst since 1974. In all cases you can see that the water is extremely cloudy and full of particles which I assume is mainly top soil. Hopefully people at the colleges etc can get on to this and assess what damage has been done and hopefully make comparrisons with areas under significant vegetation and use it to push the permaculture point.

    Gearage
     
  9. Gearage

    Gearage Junior Member

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    Bazman

    To be honest I think that is a good attitude and you should be happy. Although that was not a biblical flood it is apparently the worst since 1974 so if you consider that you are going to get that kind of event approximately 3 times in a lifetime. If you can come out of it with your perennial stuff largely intact you are not really doing too bad unlike some looser growing mon-culture potatoes etc across his whole system etc. It is a shame about the vegetables but you are just a season behind and can come back easy, infact you may find all the rot down that comes with a flood gives you a real bumper harvest in the next few years. You mention the water changing character as it passes through, that is also really encouraging and you will probably find you have taken a large ammount of top soil off some monoculturalist miles up the road.

    Anyway thanks for that information it is really positive. I just hope that some boffin is recording this stuff and getting it to people who make decisions because many people think this kind of event is going to become more common. Even alot of those actually questioning global warming (not me incidentally, I am a believer) still think that the climate in general will become more freakish. If it can be shown categorically that permaculture systems have survived so well compared to alternatively principled systems then surely somebody at the top will take notice. Another thing that I find worrying is how can these people growing GM crap say that it is contained when there are events like this.

    Great work

    Gearage
     
  10. eco4560

    eco4560 New Member

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    The media here are frequently trotting out the phrase "1 in 100 year event". Given that it is only 40 years since the last event I'm not quite sure what message they are trying to get over. That we can forget about learning any lessons from it because it'll now be 160 years before it happens again and we'll all be long gone? Or are they being more subtle and insinuating that the fact that it is well short of 100 years is a reflection that the world might be changing?
     
  11. ecodharmamark

    ecodharmamark Junior Member

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    Yes, the old 1 in-a-100, 200 (I even heard 500 on this evening's 7.30 Report) thing has been copping a flogging of late. It even made for a conversation piece in the coffee queue at uni today. Basically, I hate statistics, probability, curves, tangents, all that jazz (not with a passion, mind you), but that's what it is all about. It's just so unfortunate that the media hacks have got a hold of the concept and are now racing each other to see who can come up with the biggest 1 in-a-something flood event. Rather juvenile, and does nothing to educate the general community as to what the actual term means. And as our good friend eco points out, it tends to make the ill-informed (those of the, 'but no-one warned me' brigade) think that 'phew, at least we now have another 100 (200, 500...) years before that happens again!'

    One of the better 'handouts' that I have come across explaining it all to we mathematically-challenged folk, is this two-pager: Facts About Flooding.

    Oh, and if you get a chance to watch that 7.30 Report (first article) I mentioned earlier, please do so, as it raises some very interesting views on the subject (but forget the bit with Julia - she nearly made me fall asleep).

    Cheerio, Markos
     
  12. Gearage

    Gearage Junior Member

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    Eco4560

    It is not just these floods in Australia. Everywhere you look there are facts like "Coldest winter since 1845" etc etc and the simple fact is that the climate, whilst it may not have necessarily got warmer (although most climatologists think it) has become more extreme. It is far from being as simple as things just heating up and I think it is like Mollison was saying in the 80s that the whole system has been knocked out ofm kilter. I am from the UK and we have had what are for us two savage winters in a row and yet the summers at least in the SE have been warmer, there are always periods of hose pipe bans now and 20 years ago this never happened. Also we get more floods, the Thames barrier in London was meant to be the business and now they say we need a new one within 20 years or it is game over.
    Nearly everybody can say that wherever they are from things have become more extreme in the last 20 years, the fact remains though that there is very little concensus at the top about what steps should be taken. The problem with this type of forum is that it is essentially a bunch of people who have already "seen the light" and that statements on policy made here are unlikely to have great effect because essentially there is nobody to convert. However what I am interested in is how people come to be on this forum and what has made them turn to sustainable ideas. I am continuously stunned by the general indifference to the state of things and I just wonder what kind of event will catalyse concern amongst the masses. Keep an eye on the response of the Australian government to this and I have no doubt they will do zero apart from make a few vote catching speeches. Anyway enough ranting I am going to pick some cherry tomatoes (chadwick) and some basil for a snack.

    Take it easy

    Gearage
     
  13. Gearage

    Gearage Junior Member

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    Ecodharmamark

    Just seen it on the BBC and they have said that the floods in the S are now the worst on record. They also mention that records go back 130 years. That seems a bit short but it still begs the question where 500 has been coming from.

    Gearage
     
  14. ecodharmamark

    ecodharmamark Junior Member

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    G'day Gearage

    As mentioned in my previous thread, it is all to do with probability. Proclaiming a 1-in-100 (200, or 500) year flood event does not mean that one needs to have 100 (200, or 500) years of observed data in order to make this claim. All it means is that, as is the case with a 1-in-100, there was a calculated one percent chance of a flood of this size happening in any given year. So presumably with the case of a 1-in-200 flood, that chance would be 0.5 percent, and a 1-in-500, a 0.2 percent chance. Of course, however, the more data one has collected stretching back over the preceding years, the more accurate one's probability calculation will be... probably ;).

    That flyer I linked to earlier was very blase with its explanation, so much so that on reading it again tonight I can see we people get so confused. So, I have found the following 'fact sheet' from the US Geological Survey that I believe does a great job in explaining the process:

    The "1OO-Year Flood"

    Hope that helps.

    Cheerio, Markos
     
  15. DonHansford

    DonHansford Junior Member

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    Markos - works for me :) Here in Warwick we had a "100 year" flood event, two weeks after the last "100 year" flood event. Will it now be 200 years to the next one??? I sincerely doubt it!!
     
  16. purplepear

    purplepear Junior Member

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    It so much depends where you site your settlement as to the impact of flooding. It seems simple enough a statement but Maitland has seen some huge floods and reports say that the local indidgineous people were amused the a town would be sited on a bend of the river, with deep rich alluvial soils and obvious signs that water regularly moved through the site chosen for the town.
     
  17. Gearage

    Gearage Junior Member

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    All

    Have just seen on the BBC website (I know I get too much of my news from there) that the flood damage is estimated at about A$5 Billion. This is obviously based on structures and loss of earnings from mines and farms etc I doubt there is any calculation of the long term damage to soils, or the damage to the barrier reef from all the pesticides flooding over it etc etc. Anyway regardless it is a large amount and worthy of notice. The report goes on to state that to mitigate for this unforseen cost there will be a few measures including a 1 year flood tax (seems sensible) and a cut back on the carbon abatement programs! Truly staggering, who is advising these politicians. Surely these floods should be a huge flag waving for an increase in anything to slow down CO2 output - horrifying. The article goes on to say that the government will be offering money to jobless people to move to the worst hit areas!
     
  18. bazman

    bazman Junior Member

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    Hi Gearage

    That quoted 5 billion dollars (aud) was about public infrastructure only, roads, bridges that sort of thing.

    Nothing to do with private or company infrastructure or loss of income.

    Yeah it's crazy stuff that they are stopping or reducing funding to most gov green schemes. Mind you a lot of gov green projects have been money wasting over managed and have under preformed.
     
  19. Gearage

    Gearage Junior Member

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    Bazman

    Once again though they have shocked me with there incompetence. Wouldn't it have been great if they had something like - "we are going to plant 100 million trees to start repairing the damage done" - There must be a tipping point at which it becomes so obvious that everything is going in the wrong direction. What will it take though? You would think these floods are a big enough wake up call, obviously not though.

    Gearage
     
  20. eco4560

    eco4560 New Member

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    The talk in Qld is about the dams. The govt will probably decide the answer is to sack the people who manage these because they let too much water out / didn't release water soon enough / or something. It always works to have a scapegoat. Then the govt can go back to sleep and hope that 1 in 100 means that there won't be another even like it in the life of this particular parliament. They might even decide we need more dams. But planting trees? No on the radar....
     

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