What is considered as low rainfall?

Discussion in 'Designing, building, making and powering your life' started by DJ-Studd, Jul 22, 2008.

  1. DJ-Studd

    DJ-Studd Junior Member

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    Hi,
    what is considered to be a low rainfall? I'm currently looking at the opportunity of a lifetime - a property of several hundreds of acres. The annual rainfall for the last year is 504mm. It's obviously a lot less than what we get here near Pakenham...

    Any thoughts?

    Cheers
     
  2. trishandpete

    trishandpete Junior Member

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    Re: What is considered as low rainfall?

    That's a bit less than at our property near Bendigo, but if you have tanks and enough roof as a catchment, you can harvest water and store it. "enough" depends on what you want the water for? Calculate your daily usage, and projected usage. Look around at what is supported on properties nearby and be realistic about what you can do. Let your climate (within reason) dictate that, let the land be your teacher. And good luck! Where is this property? Pakenham area is lovely, too. Trish
     
  3. DJ-Studd

    DJ-Studd Junior Member

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    Re: What is considered as low rainfall?

    The property is in SA near bordertown.
    It has a huge permanent water license, although at this stage I'm not sure as to where the water is taken from...
     
  4. GoddamnBats

    GoddamnBats Junior Member

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    Re: What is considered as low rainfall?

    The WA Wheatbelt goes down to about 300mm a year (I'm in 340mm range). I'd class any lower than that as low rainfall.
    Moringa Orifolia will grow in that range, lots of people here have rainwater tanks to suppy their houses.
    It really depends on what you want to do on the site, permaculture wise. Maybe no rice paddies...?
     
  5. ecodharmamark

    ecodharmamark Junior Member

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    Re: What is considered as low rainfall?

    G'day All :)

    DJ: Checkout the BOM site (monthly rainfall data for Bordertown, SA: 1881-2002):

    https://www.bom.gov.au/jsp/ncc/cdio/weat ... num=025501

    Trish: Bendigo (1862-1992):

    https://www.bom.gov.au/jsp/ncc/cdio/weat ... num=081003

    ...and (1991-2008):

    https://www.bom.gov.au/jsp/ncc/cdio/weat ... num=081123

    Try not to focus too much on the historical mean average (in Bendigo's case, about 550mm p.a.). Rather it is the long term trend that should be of interest in trying to predict/project future rainfall. Try hitting the average "plot" button and checkout the bar graph. In the Bendigo 1991-2008 example, you will see that there were only 3 years out of 16 where we actually reached or exceeded the long term average - a distinct downward trend.

    Climate change is here, which basically means that we can no longer rely on past averages to predict future rainfall. Of course this means that when we are looking for a bit land to suit our needs, and the old cocky next door tells you that you can expect 'x' amount of rainfall each year, remember that this advice is based on historical data, and not future projections.

    Another good one for graphic past trends can be found here:

    https://www.bom.gov.au/cgi-bin/silo/reg/ ... ndmaps.cgi

    ...and for a taste of things to come (2070 temp. projection via the CSIRO/IPCC, emissions/percentile matrix):

    https://www.climatechangeinaustralia.gov ... temp11.php

    I guess that's a rather long response to your initial question, DJ. But I'm sure you'll agree, there are a lot of variables to consider.

    Now, concerning that abundant water supply, "It has a huge permanent water license, although at this stage I'm not sure as to where the water is taken from..."

    There is no such thing as permanent...

    Given that the property you have your eye on is located close to Bordertown (situated atop of a vast limestone aquifer), I imagine the water supply is actually sourced from the one of the perched underground aquifers that abound in that area.

    In SA, groundwater levels are monitored by the Dept of Water, Land and Biodiversity Conservation. They have a nifty database called 'Obswell':

    https://info.pir.sa.gov.au/obswell/new/ ... nMenu/menu

    This is a great resource! Click on the various wells close to where you are looking at acquiring your acreage, then click on the graphs. This will show you the GWL for a given period of time. In most cases, it's dropped (dramatically) over the past 15 years. You can use the same (above) system for accessing salinity data.

    Good luck with the property, DJ. I hope the above has been of some help.

    Trish: Looking forward to catching up with you at the Sustainability Field Day. Please make sure you make yourself known to me, so we can have a cuppa and a chat.

    Hooroo All, Mark.
     
  6. gardenlen

    gardenlen Group for banned users

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    Re: What is considered as low rainfall?

    g'day dj,

    i would consider that to be low rainfall, how was that figure determined? over a 99 year average or the average of what has fallen in very recent times?

    better off doing a past say 20 year average and take out the highest and lowest falls to get a mean average.

    but for my experience under 600mm per annum is low (especially if it all comes in one short period of the year), and will take very good mangement to be sustainable.

    another thing to work out is how many actual "rain days" occured over that period, that will give you some idea of how many days you will spend looking a tourist sky for rain. that could mean 2/3 rds of the year, and if all you rain is seasonal then that may mean a long hot dry summer of no rain or insufficient.

    in times of drought faremers sell off their worst land first.

    len
     
  7. paradisi

    paradisi Junior Member

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    Re: What is considered as low rainfall?

    don't look at the annual rain fall for one year - check out on the BOM web site what the average is over five, ten, one hundred years - will give you a better idea of what to expect.

    with good water management people live and thrive and grow things even indeserts.

    will you be on town water or tankl/bore/creek water? check out what's available and what you can use

    grow what your climate allows - no point trying bananas in that rainfall area - (let alone the winters LOL)
     
  8. DJ-Studd

    DJ-Studd Junior Member

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    Re: What is considered as low rainfall?

    Awesome, thanks guys! :D
     
  9. DJ-Studd

    DJ-Studd Junior Member

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    Re: What is considered as low rainfall?

    Would the combination of
    - Compost tea application
    - Fish Emulsion and Seaweed Extract application
    - Keyline design principals with heavy swaling
    - Yeomans Plow

    Renew the quality of the paddocks with an inconsistent rainfall? Once you've started adding some organic matter to the soil, it should improve by a greater percentage the following year due to increased water retention... no? At the very least, there should be sufficient bore water for minimal irrigation to ensure growth.

    Cheers.
     
  10. gardenlen

    gardenlen Group for banned users

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    Re: What is considered as low rainfall?

    yes dj,

    though you'd need to amke a lot of compost tea hey chuckle?

    anyhow explore various ways of swalling, rows of mulch rows of bales of mulch hay, rip lines along contours all will help by capruring any rain that falls and put it into the sub soil wher you want it, of course needless to say all lantings will be along the contours as well i guess?

    key line means dams stratgegicaly placed and nowadays permits and licenses are needed to put dams in so if you don't already have a dam, do some checking to 1.. see if you are going to be allowed a dam and of what capacity; 2.. is the soil suitable for a dam, some soils aren't.

    len
     
  11. DJ-Studd

    DJ-Studd Junior Member

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    Re: What is considered as low rainfall?

    I will have to use the Jean Pain method of producing compost and utilising the excess energy; I should be able to make a sufficient quantity of compost tea with 40 tonnes of compost :lol:

    https://journeytoforever.org/biofuel_lib ... _pain.html
    https://www.motherearthnews.com/Organic- ... -Pain.aspx

    Sandy loam, however there is clay beneath that, so we should be able to seal ponds/dams.
    We will be looking at the property tomorrow, it should be interested to see.
     
  12. gardenlen

    gardenlen Group for banned users

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    Re: What is considered as low rainfall?

    we had sandy loam and found rip swalling worked very well indeed not too expensive to do and as temorary or as permanent as they need be and no major impact on the landscape appearance, rows of mulch along the tree planting also did very well.

    len
     
  13. Ojo

    Ojo Junior Member

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  14. Jim Bob

    Jim Bob Junior Member

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    Re: What is considered as low rainfall?

    Actually, while Melbourne's long-term average rainfall is about 750mm, for the last ten years it's been about 550mm. For example, as we can see here, the lowest rainfall ever for the Moorabin airport weather station was 421mm in 2002.

    This amount of rainfall is enough for dispersed livestock, but not really enough for crops like wheat. Sorghum would do well, and of course eucalypts will be quite happy.

    There are two ways of going at it: decide what you want to do on your land, and choose your land to fit; or get any land you can, and choose what will fit on that land. I'm not sure what you'd want to do with "hundreds of acres". Most large farms in Australia lose money, and are supported by off-farm jobs. It's vineyards and (relatively) small horticultural joints which pull in the money.
     
  15. Luisa

    Luisa Junior Member

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    Re: What is considered as low rainfall?

    I'm interested to hear how the inspection went and what you were/are thinking of using the property for?

    Broadscale commercial? Boutique/niche products? Group housing and growing? Or self-sufficient food supply?

    Hoping to hear more.
     
  16. ColinJEly

    ColinJEly Junior Member

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    Re: What is considered as low rainfall?

    G'day DJ
    Have you been to: https://www.naturalsequencefarming.com? As I understand it, it does not rely on the building of dams, unlike keyline.

    A question for everybody, why is it that if you live in the country and dig a hole to collect rainwater, you have to pay the government money, but if you live in the city, the government gives you money to put in a water tank? :shock:

    Cheers

    Col.
     
  17. Paul Cereghino

    Paul Cereghino Junior Member

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    Re: What is considered as low rainfall?

    It seems that the Peter Andrew's story is about floodplain restoration... reconnecting an incised channel with the historic floodplain. The channel incision thing is a problem in arid W. USA too. Adding 'roughness' to the channel, reducing slope by increasing meanders, allowing velocity to slow during flood flow by spreading out across the floodplain.

    The Yeomans thing seems to be about working on hill slopes, starting at the slope break and holding water as high as possible, running it out to ridges, primarily for management of pasture (flood flow irrigation).

    At risk of sounding preachy, I'd suggest its not about dams or no dams or keyline or natural sequence farming, but its about understanding your landscape, your local ecological template, history, and patterns, and your position in it, and developing strategies based on that understanding. The rest are just products (not unlike permaculture). Nothing wrong with products, it is how we package stuff for transmission, products just don't think for you.

    Apologies in advance, as I don't know your local situation but here would be my analysis...
    In the country, if you impound water in a lined hole (essentially an earthen tank), you can retain tens of thousands of gallons, and keep it out of ground water, instead using it irrigate, perhaps for personal short term profit. In dry land you can grab a huge portion of rainfall and then use it to salinize the soil. Groundwater recharge by contrast would sustain base-flow in creeks during dry season. Creeks are typically an public resource not 'owned' by a freeholder (and are thus are subject to the tragedy of the commons). In the city, impermeable surface skyrockets.. 30, 50 maybe 70% of the land is covered with roof, road or compacted lawn. During rain, the city and all its crap is flushed into the aquatic ecosystem, then when the rain stops The city then sucks the surrounding region dry with its thirst for water. So country has one problem (lack of groundwater recharge, salt buildup, deforestation), and the city has another (extreme imperviousness, toxics, water dependence), therefore different policies are created to try and correct our collective death wish (and policy is usually designed for the lowest common denominator, and neglects the creativity of individuals).
     
  18. stevieray

    stevieray Junior Member

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    Re: What is considered as low rainfall?

    I think you'll find that most of the South Australian wheat growing areas have around 500mm or less of rain per annum. But that rain falls mainly in the wheat growing season.

    My neighbour in the SA Mid North says we are in an 'assured' area for wheat; he's farmed there for 50+ years. Our avg rainfall is around 480mm pa.
     

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