View Full Version : designing an irrigation system
23-01-2006, 12:20 AM
Thanx for keeping me up half the night reading all the old posts after discovering this site right at bed time! Ur an entertaining bunch to be sure!
I'm hoping someone might have some ideas/advice for me or books/web sites etc to direct me to in relation to designing an irrigation system for a 15m x 15m heavily mulched garden area.
Drip irrigation appeals (low pressure unless we go get a pump) but not sure how to overcome issues of less water at the end of the drip line, how far apart to place lines etc. I'd also like to find out about the advantages/disadvantages of different ways of setting up a system (ie drip vs spray; different types of equipment to use; how well moisture sensors work on an automated system etc). Plus of course, just any good advice (including wat not to do) anyone has to offer.
Basically I kno nothing - except I've had enough of handwatering already!!!
24-01-2006, 06:26 AM
:lol: Come on you experts get answering.
None of my many books give exact basic info on irrigation...I have several sprinklers noe of which are real good....have troulbe siteing my in line sprinkers also...how many...how far apart..but more importantly for me is how long do you run low pressure micro irrigation for effective deep watering.
24-01-2006, 08:50 AM
Can you get Leeaky Hose where you are?
I was playing around last night in my garden and I came up with this. Micro swales (the bottom absolutely level of course, on contour if your garden isn't level), or frequent pits throughout the garden. (I prefer the swales, you'll see why). 15m x 15m should be pretty easy to deal with.
Then, with low pressure water, keep filling them until you reach field capacity (the water starts getting deeper and doesn't want to soak in). I am wondering whether a drain at the end might be good for rainy weather, to help with drainage during those times. Haven't thought that far ahead.
To create low pressure water, fill a 200l drum, and let it drain into the garden swales.
I am picking that even in the height of summer, irrigation will not be an every day thing if you deep water like this.
Since you'll be into no till gardening, I wonder what would happen if you made the swales more permanent by making them deeper and filling them with mulch.
I'm guessing here when I say that 2m swale spacing might be a good start. The tops of the swales will have their own little soil microclimate, I suspect. That would depend just how high you build them. You'd only need a couple of inches if the water rate was right.
If you have good soil already, this kind of watering would be conducive to very intensive planting - after all water is now not the limiting factor. If you don't have enough water for this style of irrigation, the increased intensity of planting could mean that a smaller garden would suffice.
Since there are now two of us who might be trying this next season, please let me know how you go.
Richard on Maui
24-01-2006, 09:53 AM
I'm no expert, but you can buy drip irrigation kits that are pretty self explanatory. We have done a couple of gardens with kits that you can buy for $50 or so. Some have built in emitters that are supposed to not clog up as easily. One system we had featured valves in the larger supply line, before all the little branches which were smaller and had the emitters, so you could give extra water to some legs of the system than others.
Pressure reducers are pretty standard little plumbing fittings.
Mike's ideas are all good... I do like the leaky hoses that are made from recycled car tyres, although have you have dragged one of them up against your bare leg? I did that the other day and it hurt!
On another tack, a friend of mine irrigated his bamboo nursery using hollowed out pieces of bamboo, joined together with clamps and bicycle inner tubes for gaskets. I think he stuck emmitter tubes into the culms and had them going off to pots and propagation beds. It worked pretty good for about a year before it just started to leak everywhere...
24-01-2006, 06:54 PM
G'day macree (Ree),
I really *love* Mike's suggestion of swales and infrequent deep watering as opposed to drippers or sprays, but I guess it all depends on your site, the plants you wish to irrigate, water availabilty, etc., etc., etc., and I am a little biased - I just *love* mimicking nature with swales and infrequent 'floods', myself.
Some time ago Gardening Australia (ABC TV and Magazine) did an article on Josh Byrne's permaculture garden that incorporated a grey-water recovery and drip irrigation system setup. The following link provides a really great starting point for any drip system:
Good luck with it, and don't forget to let us know what system you eventually design and develop.
27-01-2006, 02:51 AM
Thanx for the suggestions -the swales do sound like a good idea - one I hadn't considered - does anyone have swales in their vegie garden?
I've used the leaky hoses before in another place - we used bore water there that had a heavy clay content and the hoses didnt' work well for us - we don't have clayey water here tho - and wonder if they typically work well - it was just our water?
The ABC website was great - thanx
27-01-2006, 03:32 AM
You might take a look at this site: http://www.dripworksusa.com/
It is highly recommended by some small growers that want to conserve what water they have, and they say the prices are very reasonable.
I don't know that they sell in Australia, but maybe you could look through the site and maybe adapt what is available to you.
27-01-2006, 03:41 AM
27-01-2006, 11:07 AM
Hi there, isn't watering a frustrating thing? I love my garden, I'm an obsessive planter but especially in springtime when the soil everywhere looks great I keep poking in the odd seed here and there. then having to water I usually go crazy around Xmas time, often right through til about the end of Jan!! My family get frustrated with me too, just as well they get to eat fantastic food, it calms the beast. I have just put in some oozehose into my parsnips but found that it just runs right to the bottom of the bed and floods the surrounding area while my parsnips are dry. I know it works but I must have done something wrong. I still find that you can't beat a slow trickle on a tree once a week to give a deep water. One of the reasons I've hesitated with the watering system is that with veges the kind of watering required keeps changing. I will persist with the oozehose though. i put one section looped around corn and basil. I then put sheets of newspaper around and topped it with lawn clippings. So far this is working. Good luck!
27-01-2006, 04:21 PM
Yes watering plants is nearly as hard to figure as how to save the planet .....
Tried Sprinklers....too wastefull..
Tried Drippers .....crap blocks up.
Tried hand watering....now thats better ..
With good early thinking mulching can 1/2 your problems.
Selecting plants that dont require huge water helps,if able to.
Observation of needs of vegetation prior to watering.
In my 6th summer now and hardley ever use my lines any more,I find that with my fruit trees now i may only need to water as fruit grows prior and after no watering.Have found if you molly coddle vegetation,you can end up with week shallow rooted trees, who die at the first dry spell when they should be established,....This can take a few years mind you, but have been doing same every year.In first or early years Id favour the flood method..
Leave low hose on near vegetation leave on to fill the surrounding area
(root ball zone+) cover with mulch......
If your like some who only get tap water out of your reticulation,well nothing much happens untill it rains again. Tap water is crap,
Just realised your on about veges but it still the same,I just stopped growing veges and concentrated on fruit trees,and grow veges in winter only lolol...
28-01-2006, 04:22 AM
Here are two books available on the Internet for free that might interest you. They will both take you longer than a few minutes to read but they might be a start of something new
Gardening without Irrigation
http://www.soilandhealth.org/03sov/0302 ... frame.html (http://www.soilandhealth.org/03sov/0302hsted/030201/03020100frame.html)
http://www.soilandhealth.org/01aglibrar ... frame.html (http://www.soilandhealth.org/01aglibrary/010102/01010200frame.html)
Both of these books are directed towards growing crops.
I have not read them all, but from what I have read, this is not something you can start to do half way through the season!
28-01-2006, 10:51 AM
I suspect that much of Oz tend to be like our American Southwest: hot, dry and sandy.
The old (long gone) Anasazi people there and many of the current native people reverse the raised-bed technique and dig shallow beds 4"/10cm to 6"/15cm deep. The water stays in the beds, rather than running out into the paths.
I wonder if this method is ever used down there?
29-01-2006, 08:07 AM
hmm - great reading sites and suggestions - now I've got to digest and decide .....
Thanks Mike - two good resources there... :D
30-01-2006, 09:12 AM
first- don't bother with moisture sensors - they rarely work unless placed 'just so' and are expensive.
the best drip system is the in line drip system, Netafim make the most available one. the drips are inside the 12 mm poly pipe, and don't get damaged or blocked easily. easy and fast to install.
another option is to punch small holes in the base of a container (say 5 litre) and bury these around the root zone of the plants. this will provide an ingound soak system that you should only have to fill every other day.
30-01-2006, 10:21 PM
I too am a big advocate of the Leeaky Hose product. I have been trialling it for since the late 1990's on small and large sites (including one 10ha tree crops site) and am very happy with its performance. Most dripper systems require at least 8m of pressure whereas Leeaky Hose only requires <1m which has obvious benefits where lack of slope is an issue. Also its ease of application warrants mention also. Its additional application in aeration is an added benefit.
05-02-2006, 06:03 AM
I've thought much about your suggestions and info provided by web sites. From Mike's web sites we were influenced to rip our garden site as deeply as we can (without the ripper wings on) before we do anything. That was a painful decision to make as the garden is 1/5th planted to annuals and 1/2 of it has been mulched already for no dig gardens - but longterm gain over short term loss!
The first planting over the entire site will be potatoes and deep rooted green manures to open up the soil as much as possible. Formerly we would have intensively planted, but have decided to try widely spacing plants (in deep mulch) to reduce watering needs.(60 inches annual rainfall - water is an issue here but space isn't) We're subtropical here so are going to put up 50% shade cloth over most of the garden and use shadecloth as windbreaks until the living windbreaks get up - hoping this will help plants cope with heat and help to conserve water by cutting down evaporation a little too. (We 'recycled' heaps of shadecloth from the local dump a few months ago) We'll give the leaky hoses another go - set them on a timer for early morning, flooding the bed as infrequently as we can.
Thank you all for your information - I learnt heaps and am going in a slightly different direction as a result.
06-02-2006, 06:52 AM
Not quite sure that you have spotted the difference between leaky hose and Leeaky Hose. Leeaky Hose is the trademarked name for a hose that works by capillary action through the walls of the hose - not by individual holes.
You say you are putting it on a timer - which probably means higher pressure. Leeaky Hose uses very low pressure. That's what made me ask this question.
07-02-2006, 06:23 AM
I had in mind the black ones that ooze water the whole length of the hose - we have reasonable enough pressure (not high tho) from a gravity fed tank a good 40 meters or so uphill. Wanted to use a timer so could set it to go off in the wee wee hours of the morn (about 3 or 4 am I was thinking) so had good soaking time before it gets warm. Do you think it will work ok??
07-02-2006, 07:13 AM
I've been a bit put off the Leeaky hose in the past because of the tyre content and concerns about heavy metals. There has been so much said in the past about using tyres in vegie gardens possibly resulting in unaccaptable levels of heavy metals that I wondered what happens when the tyre is granulated and water run through it. Anyone know?
07-02-2006, 07:15 AM
Yep, that's the one. Gravity fed water is just what it needs.
07-02-2006, 07:18 AM
From what I have read, once you bury tyres they become pretty much inert. And of course, the tyres have to go somewhere, so if they are okay, why not use them for irrigation? I even looked into building a house with them. Offgassing was a big concern but those that have built them have done the study and have concluded they are okay.
In the sun is a different story - of course.
But I can't vouch for the hose.
07-02-2006, 08:38 AM
Thanks Mike that's good to know. Makes sense that being buried and away from UV would change the results of the material breaking down. I have a tank sited just above my vegie garden and using the Leeaky would be a useful way to irrigate it.
09-02-2006, 02:29 AM
Macree, I have a drip system because we don't get rain from April to November, and I have low pressure because I use gravity flow water from a 600 gallon tank up the hill. I can run three 100-foot lines at a time with the pressure I have.
I'm also a fan of deep watering not as often so the roots are forced to go deep for water, and not stay shallow and lazy.
But the problem with the dripper emitters is with my water they clog up with minerals and sometimes small pieces of debris, and there's no way to easily clean out hundreds of feet of them. So I just bought the small 1/4" line and 1/4" T's, and leave the T end open in the line where the water comes out. I've timed them to see how long it takes to get 1 gallon or 2 gallons, the way the emitters are fashioned, and I only leave the water on that long (15 minutes in my case), not for an hour, the way you would with an emitter.
Another good thing about this is you don't have to wait an hour, which if you are doing several areas, could take several hours, and that's just not doable month after month. Something will crop up where you can't be there to switch the waterlines.
I like the idea of swayles, and have toyed with it, but they fill up with weeds, and are a lot of work to keep clear so the water can flow evenly, plus on a hot day a lot of water gets lost to evaporation.
And I second the mulch approach, I keep 3 to 6 inches of leaf, compost, straw mulch on everthing all the time. :)
19-02-2006, 07:33 AM
thanx for the info - it's so good to read problems with systems as well as what people are happy with.
28-02-2006, 12:56 PM
I was wondering if anyone had any suggestions for how to irrigate a commercial sized (7 circle) mandala garden on a slope using dam water that has a few metres of head. The mandala gardens are being designed along the Linda Woodrow lines (which is discussed elsewhere in this forum); 7 circles will have a total of 23m radius and 42x 2m radius vegie patches, and around 30 fruit trees.
The particular issues that i think are pertinent are:
* Slope, moderate to low
* Low head
* Beds with mixed vegetables
* Circular beds
* Beds at different times of maturity
* Fruit trees need to be irrigated also
Any thoughts would be much appreciated!
04-03-2006, 12:33 PM
I found that a leaky hose connected to a rainwater tank in a circle worked very well . Apparently the pressure is even around the circuit if it isnt in a straight line . If I wanted an individual plant to get some more water one year I just put a pin into the hose at that spot . The leaky hose was connected to a rain water tank that sat about 30 cm above the bed and left " on " all day . This system has worked on sloped and level ground in 3 different places we have lived in and it worked fine for all vegetables and herbs including parsnips . At our present home the circuit is larger and connected to a tap with timer . I also have sections with drippers running off the main circle. Apart from tap timers not working properly I have had no problems .
05-03-2006, 03:36 AM
Personally, I wouldnt use drippers in a vegie garden.
I use tiny paths which often have more mulch on them than the garden beds.
I have always used cheap pop-up sprinklers on 3' pvc risers for my veggie gardens on self-compensating lines, ie, all lines are connected back to each other. All my poly is standard 19mm and fittings are easy to get and cheap.
I have always watered just as the sun goes down for about 2 hours 2 times a week and an overnight every week or so. I have never had probs with mildew or humidity probs even though I live in the tropics.
Corn is the only tall thing I have grown so consideration had to be given as to where I put it, the sprinklers are there permanently.
My garden is on 19mm dripper lines with good filters [due to calcium], years ago at auction I bought a heap of cheap adjustable drippers. These are easy to clean and all lines are flushed when I remember...Some of these drippers have been in action for 20 years.
Once a year or so, I put 5litres of pool acid and some red food dye in my main water line and let all taps just dribble till I see colour then I turn them off and then do all the garden lines. [I would use vinegar but imagine I would need 200 litres.] I leave it in the lines for a while and then give everything a huge flush. This removes a lot of the calcium build up in the lines and fittings. I dont know if the acid has done as much damage as the calcium, which is very abrasive on tap fittings..
I use vinegar to clean my dripper filters, which I bought cheap at auction so use two on long lines. I have one half-inch line I buried 20 years ago that still works fine. Most trees are watered by dripper and again by sprinkler. I put a 2inch ring line around the house when Telecom were putting the phone lines in, it cost me a carton for the ditchwitch operator to do it. One of the best things I did. Although I think he drank the carton before he started as it wanders all over the place.
I am fortunate to have an excellent bore and only pay pumping costs..
05-03-2006, 05:50 AM
We try to do as much rain fed/non-irrigated cropping as possible, which, some years, works really well. This years dry season which we arein the middle of, for example, it has rained every three days, at least, so all looks wonderful. PtOer years we have had problems with up to 5 weeks without rain (place gets DRY!).
Floot, your experiences closely parallel mine, both in climate and using pivot irrigators. We also water at sunset....
We have lots of broccoli this year, plus the usual veggies down in the vega (seasonally inundated flood plain). The trees all look good too.
Leeaky Hose sounds great, but is not available here. The products that are avaoilable, basically hoses with holes in them for drip irrigation, plus drip irrigation components and little pipes, etc, all tended to get filled up with sediment or mineral deposits. This may be less of an issue now as we are pumping our water out of a spring (got the pump installed and finished the last of the 600 meters of pipeline two days before we hosted the first Permaculture Design Course in Belize...) and not the river (which comes from another spring about .5 e from our property line).
05-03-2006, 08:08 AM
Just a quick edit before I get anyone off track.
I havent tried or seen those leaky hoses for sale. I have seen them on garden shows.
My first irrigation system was provided by 2 types of free, very early, Israeli PVC irrigation gear. A leaky hose thing and a dripper with little screen style drippers... Both clogged up very quickly in my conditions. I still use the 1/2 inch Israeli emitter/dripper pipe which clogged in fairly short order and just stuck purchased drippers into the pipe.
Also I have had one of those pale green holey things that people put on their lawns and that blocked up in fairly short order...
Like Chris, I have plenty of water but the quality can vary. Unlike Chris we do not get dry season rain and get incredibly evaporative weather. This lasts for at least 5 months.
So I wasnt advocating I have the best system, just one that works for me. The tropics can be very unforgiving and plants, especially young leafy ones can die pretty quickly. I have to be able to tell at a glance that all is ok.
07-03-2006, 09:07 AM
I was talking to my boss Howard Yana Shapiro the other day in Viet Nam and he said that they used a Leeaky Hose product at the Seeds of Change Farm in New Mexico. Perhaps you could contact them for more info.
07-03-2006, 09:44 AM
Leaky Hose... made I think from recycled tyres ...is available from most Mitre 10 and Bunnings. I know many householders find it great but my local hardware bloke said blocking up was a problem if not on town water, so I've stuck to drippers and low pressure sprinkler.
08-03-2006, 09:38 PM
G'day, an inline filter certainly doesnt hurt though we dont have one here with over 10km of Leeaky Hose connected to 50mm & 25mm mains from dam water. Blockages are caused by incorrect pressures (ie too high!). I have 13mm taps at ends of the leeaky hose for a yearly flush (start of irrigation season). Another trick I do is to fit simple grommet and 13mm plug fitting to the main (after drilling a 16mm hole) and connect 13mm LDPE pipe then loop it around in a 300mm high staked loop with a 13mm valve at the top of this loop. This not only brings the valve off the ground but also serves to settle some of the solids in the pipe which are dealt with by the flushing.
21-03-2006, 02:27 PM
Thank you for your replies. I think i'll have to keep all my lines above ground so that i can try out different systems and see what works.
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