Swale options.. help needed

Discussion in 'Put Your Questions to the Experts!' started by bpl, Jul 19, 2016.

  1. bpl

    bpl New Member

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    Hi, I have some questions about my first swale, and I'm keen for some suggestions/ideas/feedback.

    Background
    This shot is looking down hill (gentle slope) towards the swale which is (currently) 2' wide X 1' deep X 40 meters/yards long.. this swale basically catches ALL the water that falls on this, the front yard (the house faces north).
    [​IMG]
    To the left of the mango tree, below this swale is an 18 metre X 10 meter pond (actually a long ago attempted swale, which kind of evolved into a pond).. it's about 5' deep at it's deepest, and captures all the water that spills over from the swale.. the swale is on the same contour level as the house slab..
    [​IMG]
    Having dug the swale, I'm getting ready to chop and drop then deep mulch.. followed by a nitrogen fixing crop. This area will (hopefully) become the food forest, which will expand up the hill (a little bit) where I in visage further swales and possibly some cropping.
    [​IMG]
    Here's a closer look.
    [​IMG]
    Questions
    1. Is the swale wide/deep enough? I've had a look at the calculator, and I've read a little bit on the subject, but I'm still unsure. I'm thinking it needs to be deeper and wider? The last rainfall event was 90ml, which overfilled the swale.The (uncompleted) spillway on the left fed straight in to the pond, which also overflowed. It took 2 days for the swale to become empty.
    .. I'm considering running the down pipes on this side of the house in to this swale.
    2. What next for the swale? Hugel swale? Just leave it like that? Install a weeping pipe?
    3. What sort of swale intervals (how many swales/how far apart on this part of the yard?) should I consider. If I walk up hill from the first swale, every 3 meters gives me 2' in elevation.
    Feedback
    I'm open to any and all advice.. any general-type suggestions or ideas about what could be done here, please :)
     
  2. S.O.P

    S.O.P Moderator

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    I would batter the edge (low sloping angle), which will widen it so you can walk along it comfortably (it's an ankle-rolling trip hazard it seems) and also maintain it, if required (think grass cutting). Your catchment isn't huge so a failure wouldn't be catastrophic.

    Personally, I've left swales behind due to the labour, and moved into Vetiver as a permanent swale-type installation (swales aren't permanent as they slump unless maintained) which also nets me regular mulch. If I was installing Vetiver there, I would make them 5m apart and use straight lines from your original contour for ease of maintenance. They self-form terraces over time so being slightly off doesn't matter to me. I'd also plant Vetiver hard up against your bitumen driveway as it prevents cracking of the edge but that's a different story.

    One of the arguments against swales is that they concentrate water in one place and change the natural hydrology of areas (which you need to keep in mind with overflows). A lot of people now attempt to retain water in every location rather than in designated areas through mowing differently, ripping/forking, pasture management etc. So if your plan is to turn that grassed area into a garden, micro-swales or even forking a contour garden with some mulch would be enough to disrupt the water flow and establish some trees. I'd raise your catcher height on the mower to maximum, and mow less too.

    As for your downpipes, I'd put a tank between that and the overflow for the swale, at least. Even a tank at the top of the driveway, pumped from a 1000L sump tank at the house may get you some nice gravity-fed gains (without seeing the whole picture). Dig a trench, lay two lines in it, blue goes to the gravity tank under 240v, green could be pressurised with gravity (poor flow perhaps slightly better with diameter of pipe increased) or a solar pump. A slimline tank against the house wall would not be too ugly.

    IMG_1657.jpg

    Watch this for a full farm design:

    Just a thought...
     
  3. bpl

    bpl New Member

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    Thank you SOP, that's really got me thinking. I have some homework to do on Vetiva.. on everything.

    I can see that a completed contour map of this block would make it easier (is essential) to discuss it/ design it. Or perhaps a video tour? Or both. The problem is, time spent drawing contour lines on a map is time not spent digging/planting..

    Having said that, I do have a map of sorts (with one contour line drawn and most of the permanent features marked), albeit incomplete. I'll get back on to that..
     
  4. S.O.P

    S.O.P Moderator

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    Yep, you can do that. Or just start wherever and build up from there. Obviously, looking at your photos, that grassed area looks like where you will get most of your 'production' from so 'biointensive' contour beds may suit. 1m wide and well-irrigated. https://goldcoastpermaculture.org.au/dan-shows-us-the-gcp-bio-intensive-garden-system/ (link broken at the moment but may come good later).

    Some good guides that may suit some part of your climate:

    https://www.remoteindigenousgardens.net/wp-content/uploads/Cook-nomowgg_20130801-reduced.pdf

    https://withoneplanet.org.au/downloads/pdfs/Permaculture_Guidebook_English.pdf

    Curramore1 on this forum if you go through his post history often has some good things to say, below is a list of trees he once recommended. Below that is what some of the GC permaculture people were growing for perennial tropicals.

    Code:
    Curramore's (Blackall SEQ)
    
    Banana
    Lime
    Emporer Mandarin
    Washington Navel Orange
    Late Navel Orange
    Valencia Orange
    Macadamia
    Hass Avocado
    Cherry Guava
    Grumichama
    Jaboticaba
    Ice Cream Bean
    Mulberry
    Tamarillo
    Passionfruit
    Paw Paw
    Fig (White Adriatic, Black Genoa, Brown Turkey)
    Grapefruit
    Jakfruit
    Wampi
    Fejoia
    Lemon
    Kaffir Lime
    Ruby Grapefruit
    Blood Orange
    Pineapple
    PErsimmon (Jap non-astringent)
    
    
    Others
    
    Acerola Cherry
    Miracle Fruit
    Pitaya
    Lychee B3
    Mandarin (Imperial, Ellendale)
    Persimmon
    Cherimoya
    Carambola
    Pomegranate (Fuyu)
    
    Gold Coast: We concentrate mostly on tropical perennials cassava,aibika,taro,yam,ginger,banana,
    sweet potato,plenty of  herbs and salad greens that act as ground
    covers,flowers,cosmos,sunflowers,daisies,zinnia,gerbras 
    for beauty and to attract beneficial insects,some support species we could use for mulch like 
    crotolaria,lemon grass,pigeon pea,comfrey and quite a few others.
    
    Just go hard on the Casava and take an arid approach,moringa,aibikas,maranta,yacons will all still do very well upland taro pigeon peas,vetiever,any acacia,cassias,paw paws and guavas,papaya all do great
     

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