Low Pressure Drip Irrigation Part 1

As promised, here is the first of my drip irrigation posts, inspired by a visit to my friend Michael’s house yesterday.We woke up this morning to find the swimming pool extremely close to the top, just from the rainfall overnight.  It must have rained all night, which is very rare in my part of the world.  With nowhere else for the water to do, and not wanting to lose any more down the storm-water drain, I sprung into action.

drip 1

Due to the limited space I had available, I figured that small was the way to go, so I rushed down to Bunnings and bought two 100 litre water butts to start the irrigation system that would be fed from the overflow of my existing 2300L tank.  As soon as I got home it poured down, and I quickly gave the butts a rinse to get rid of the plastic bits from when the manufacturer drilled the hole for the tap.

I put one on at ground level and I put one on an old pot that I once filled with cement for an umbrella stand for better pressure.  I then filled them with the garden hose connected to the tank and filled them up.  So far so good, I thought, but then it started to pour down with rain and I got drenched.  This is what they look like later on in the afternoon, fully hooked up to my new system.

drip 2

The tank quickly filled up again, and I was back to square one, with no way to get the water to the garden because I hadn’t gotten around to connecting anything up.  So, after a quick lunch (still raining), and about an hour of planning how it was all going to go together, I made a comprehensive list of parts required and I headed off to Bunnings again, then purchased about $150 worth of plastic fittings and a 200 L rainwater butt to add to the system.  I also bought 4 hebal eco-blocks to make a stand for the larger butt so that it was above the hight of my garden beds.When I got home the rain was just easing off and now a steady drizzle set in.  Wonderful stuff to work in and I had to wear a ball cap to stop my glasses from misting up!  Now, straight back into work.  I fully dismantled the irrigation system that had gone unused for so long.  It consisted of a 24 volt solenoid, about 8 metres of 19mm poly pipe and lots of clips and elbow joints.  It took about an hour to dismantle and remove the wire run which fortunately was only cable tied to one of the electrical conduits running along the top of the car port.  I had kept heaps of other long 19mm lengths and lots of 13mm pipes saved when I ripped out the system in the front lawn.  So, I found a suitable length on 19mm pipe and pushed it behind the water tank.

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Then along the front of the deck, past the worm farm, behind the conifer and it just reached the front of the garden bed.  Excellent I thought, and began to start work on the tank end.  I am so glad I had the forethought to install an isolating valve before the brass tap, which made things very easy to install, with no water loss.  This is how I connected it;

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I removed the brass tap, connected a male to male 20mm plastic riser pipe, then added a standard tap fork with two little taps on it and screwed a standard quick clip nozzle to one side so I can still connect the garden hose to the tank if needs be.  To the other side I connected a female to female 20mm pipe to a 20mm male to 19mm barbed connection and with a series of 19mm elbow joints connect it to the main 19mm poly pipe.  All nice and neat and I made sure I used Teflon plumbing tape around each of the threads to stop leaks (a valuable lesson learnt from the system on the other side of the house).
A quick test to see if water came out the other end of the main line 19mm, and then a pressure test to check for leaks by putting my thumb on the end.  No leaks thank goodness.  Then I started work on the solenoid so that I could use mains water twice a week via my automatic sprinkler system.  This is how I put the next part together;
drip 5

I cut the main 19mm line at the bottom, inserted a 19mm T piece and then hooked up the solenoid to the wires and to the mains tap.  The wires were already there from the old system so there was plenty of length to connect to the electric valve.  The solenoid prevents rainwater from flowing into the mains town water which is not allowed by law, and I added another lever tap just to make sure I can isolate it further if I ever need to.  I did a quick test to check for leaks between the lever tap and the solenoid valve and all was good.

It was a bit fiddly putting the pipe together between the main lever tap which was 20mm to the steel elbow joint of 25mm but luckily I had all the bits from the old system.  Then I moved on to connecting the two 100 L water butts into the system.  No use having them there full of water if you can’t integrate them in, I thought.  So this is what I did;

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The taps that came with the water-butt had 15mm barbs and no matter how hard I pushed, I could not get 13mm poly pipe to fit.  So, I trimmed a bit of normal 15mm garden hose, forced that on, and then I could get a 13mm elbow onto each butt and connected them both together.  I used a 19mm to 13mm T in the main line just behind the lower butt.  Once again a quick test and no leaks and water flowed out the end of the main line.  I now proceeded to set up a pipe to connect to the 200 L water-butt on the other side of the conifer tree;
drip 7
You can see that I put another 19mm to 13mm T into the main line and put a length of 13mm poly pipe on in readiness to connect the 200 L water-butt.  Firstly I had to finish off the main line pipe to the back of the garden beds.  You can see I have begun to dig away the Tuscan pebble to expose the weed matting.  I put in a 19mm elbow and ran it so that it was level with the edge of the first garden bed.  Then I dug a trench all the way along the edge of the bed and laid the main line.
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This is the finished product with a length of 19mm pipe sticking up with a bung in the end, ready for tomorrow’s task of laying another 19mm main line across the back of all the garden beds.
drip 9

I filled in the small trench and got to work setting up the hebal eco-brick base for the 200L butt.  I levelled off the bricks then laid two on top, check the level again and made sure there was enough room so that the base of the butt fit evenly on the stand.  I had to trim a little bit of the conifer back so that it was not sticking into the plastic butt.  Then came the funny part.  The 200L butt did not have a female thread pre-cut into the water butt for the tap to screw into like the 100L type, and required you to put the tap fitting into the hole on the outside and then screw another part on the inside.  The only way I could figure out how to do this (because I couldn’t reach the bottom), was to turn the butt upside down, put it on my head with one arm inside and ask Ben to put the tap in the whole and I screwed the inside part tight.  It reminded me of the Mr Bean episode of the Christmas turkey on his head!  Ben and I laughed when we finished it.  The tap barb was 15mm again, so another piece of garden hose and I connected it to the 13mm pipe I had installed into the main line earlier.  This is how the connection looked.

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Easy access to the tap, and now all connected and looking very smart.  Here is the 200 L butt in all its glory on the nice eco-block stand.

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Nice stand, and all level too.  Now, because I had put a bung in the end of the main line, and because this smaller tank was lower than the water level in the main 2300 L tank, all I had to do was turn on the little tap at the main tank, and then turn on the tap for the 200 L butt and watch it fill up from the bottom.  Water will always find it own level, so as long as the main tank level is higher, then I never have to drag a hose around to fill it up.  Same goes for the smaller 100 L butts.  Bloody genius I thought.  I just have to make sure that I put an inline 19mm tap at the start of the garden bed system so that I can isolate all the beds to continue to use this method of moving the water around.Tomorrow, I will start on the garden bed dripper part of the project.  I am totally knackered after a big day of problem solving and working in the drizzly rain.  I am glad I went to the gym this morning, because I needed all the energy I could muster for this 5 hour session of irrigation madness!

drip 12

See you all tomorrow!  Keeping it green,Gav


  1. Maxine says

    Hi Gavin, really keen to see photos but for some reason they are not loading am it doing something wrong?

    • Gavin Webber says

      Hi Maxine. All fixed, it was a technical glitch my end. It looks as if the pictures didn’t copy across during the migration from blogger to wordpress. Thanks for letting me know of the issue.


  2. says

    Thanks Dad. We are saving up for a larger tank now, so we can save even more rainwater when it does rain. We lost so much the other day down the storm water that it probably makes sense to capture as much as we can from these single rain events.

    Hoping to get between 3000-5000L fitted in near the front gate. It will be fed from the roof over the decked area and the front down pipe. I also want to put a gutter on the carport where the solar PV is. So much water comes off it, and it would probably fill another 2500L tank easily. We have the space in the pool area to put it as well. I feel quite confident that I could install it myself. I just have to get the massive things over into the pool area!

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