How to install a drip irrigation watering system

[Adam_W]

Difficulty: Beginner

A drip irrigation watering system is a reliable way to make sure every plant in your garden is getting the right amount of water it needs to thrive. It also improves water efficiency by delivering water only to where it’s needed.

This guide shows you how to set up this simple watering solution to help ensure your plants flourish over the warmer months.

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Video Tutorial

Steps

Step 1

Run the tap you plan to connect your system to into a 10 litre bucket. Using the stopwatch on your phone, time how long it takes to fill. If your 10L bucket fills in 30 seconds, that is 20 litres a minute or 1,200 litres an hour (2 x 10 = 20, 20 x 60 = 1,200L).

Step 2

Your drip line will be marked with output per dripper and dripper spacing. This allows you to make approximate calculations to ensure you do not connect too much pipe to one tap or zone.

The line pictured emits 1.6 litres per hour per dripper and has 10 drippers every 3 metres or 3.3 drippers every metre (10 ÷ 3 = 3.3). Every metre of line will supply 5.28L of water an hour (1.6 x 3.3 – 5.28). For simplicity call this 5.3L. If you needed 100 metres of drip-line, then the system would require 530 litres of water an hour (100 x 5.3 = 530). Well within a 1,200L/hr output.

Step 3

Clear the area where you plan to lay your lines. Any mulch will need to be cleared back so the drip line can be in contact with the soil beneath.

Step 4

Roll out the main sections of your line and loosely peg in place as you do so. Place a peg at every corner and one every 1.5 to 2m of pipe or as needed to shape and secure your system. Aim to position the drip line pipe around the area of the plant’s drip zone (the edge of their foliage canopy) as this is where they will have the most feeder roots.

Measure and cut any short sections for joining, cross lines or for hoops around plants. When cutting drip line pipe, make sure all cuts are at least 5cm away from a dripper.

Step 5

Now add all joiners and secure them with pipe clamps. You may need to use pliers to firmly close the pipe clamps. If you are happy with the position of your pipes, finalise by securing with pegs. Use a hammer or mallet to hammer in the pegs but make sure you do not crimp the line.

Step 6

At the furthest point in the pipe from the tap use a T-joiner and a short section of poly-pipe to add the in-line tap. This is used to flush the lines clean after installation and periodically for maintenance. Ensure it is secured with hose clamps.

Step 7

Connect your system to your water computer (if using) and tap. The Back Flow Prevention Device (BFPD) should be fitted directly to the tap above the computer or timer. The BFPD will stop water in your irrigation system back flowing into your pipes if there is a drop in water pressure of the mains supply. Program your computer now too.

Step 8

Run the system for a few minutes with the purge tap open to clear any water or debris that may have entered the pipes during installation. Close the tap and then check a few drippers to make sure they are running well. You can now cover your pipes with mulch and start watering.

Materials

• 13mm drip line

• 13mm poly pipe

• 13mm elbows, T’s and pipe clamps

• 13mm in-line tap

• Turf pegs

• Tap connector

• Timer or water computer

• Back flow prevention device.

Tools

• Pruners, heavy-duty scissors or poly-pipe cutter

• Tape measure

• Hammer or rubber mallet

• Combination or multi-grip pliers

• Hoe or garden spade.

Images

[river]

Thanks for the video on installing a drip irrigations system. We have a shelterbelt that is on a hill, we are planning on installing a T shaped trickle system but are not sure how to install a check valve in the middle of the system for the uphill section of the system.

The tap is in the centre point. The 13 mm black pipe will drop about 1m to get to the start of the 13mm drip line. At the T junction, we were planning a 3-way join to connect the different arms of the drip line. One side of the T will rise about 1.5 m higher and the other end will drop down the hill by about 1 m. I think we will need a check valve on the uphill section of the irrigation to allow water into the top section of the system but I have not been able to find anything that will connect to a 13mm poly pipe. We have check valves that connect to the tap but this is a different connection and I would need an adapter to connect the 13mm end to the check valve is there another system that people use for situations like this? Thanks for your help!

[EricL]

Hello @river

Welcome to the Bunnings Workshop community. It's a pleasure to have you join us, and thank you for sharing your question about drip irrigation.

Let me tag @Adam_W to make him aware of your questions. Would it be possible for you to run your irrigation line up the hill and place the split at the top? This will prevent backflow from happening in your system. However, if that's not possible, I suggest installing Pope 13mm Tail x 15mm BSP Male Director together with a Kinetic Chrome Backflow Preventer. In order to convert it back to a female fitting, you'll need to use a Garden Rain 15mm Female To Female Rural Poly Irrigation Coupling and then place another Pope 13mm Tail x 15mm BSP Male Director to re-attach it to the irrigation line.

The body of the non-return valve is made of brass and will last a long time. Would it be possible for you to draw a diagram of the complete irrigation system including the location of the tap? This will give our members an idea of how your system is laid out. We can then make recommendations on how to run your system efficiently.

Please keep us updated with your progress, we look forward to seeing your irrigation system up and running.

If you need further assistance, please let us know.

Eric

[Itai]

Hi @Adam_W Thanks for this video ... it's really useful. I'm about to embark on a large garden design project here:
https://www.workshop.bunnings.com.au/t5/Garden/Project-Landscaping-our-front-garden/m-p/101394#M9800

My plan is to run 3 zones to this garden.

The first zone for the whole native garden (left of the first hedge on the left), which will simply be fed by running drippers the entire way through. In your video, you mentioned that drippers should be closed loops, so if I have a really long snaking drip line, where would I close that loop to? Where it got fed by the poly pipe? 

The second zone to run a drop line for the forest style fairy garden. This one is quite more complex, I'm not sure the best way to run the lines through here. Should I be running any individual drippers to particular plants in addition to running drip line, or is the dripline enough?

Can individual drippers on 4mm pipe be connected to driplines, or only to normal poly pipe?

The third zone will also be in the fairy garden, but to power misters for the more sensitive plants such as ferns, swiss cheese plants, etc, which enjoy collecting water on their leaves. This is to create the more humid foresty environment.

The reason for the three zones is to actually break up the timing. The native garden will require much less water than the fairy garden. And the misters will be used more often to keep the garden humid.

I'm planning to run all of this through the B-Hive system, with solenoid valves, so I can make sure I'm not wasting water when it rains

If you have any advice you can share in relation to watering our design, I'd really appreciate it. 

Thanks

Itai

[EricL]

Hi @Itai

I always suggest putting it down on paper, this gives you a much better idea of how the lines will run and where you need to make returns into the system. Using Adam's suggestions, I recommend making multiple circles so that you hit all those areas that need water. I recommend checking the pressure that your mister needs before you assemble your system. If there's not enough pressure in the system your misters will not work correctly.

Please keep us updated with your progress,  we look forward to seeing your watering system come together.

Eric

[Adam_W]

Hi @Itai 
A few answers for you...
"...so if I have a really long snaking drip line, where would I close that loop to?..." - use plain black poly-pipe to create a 'blank' line that runs back to the beginning Use a straight joiner or elbow to connect at far end and then a T back at the beginning.

"...Can individual drippers on 4mm pipe be connected to driplines, or only to normal poly pipe?..." Individual dripper or bubbler heads using 'spaghetti pipe' are excellent for delivering water to specific plants. I haven't tried to connect to drip-line but I suspect it might have impacts on pressure regulation in the drip line. Not sure about that.
"...The reason for the three zones is to actually break up the timing..." I cannot recommend this highly enough. If you have areas with very different and specific needs then creating zones is the way to go.

[danielg]

@Adam_W What back flow prevention would you recommend?

[MitchellMc]

Welcome to the Bunnings Workshop community @danielg. It's brilliant to have you join us, and many thanks for your question about backflow prevention.

Let me tag @Adam_W to see if he has any preferences. However, you'll find the Holman 20mm In-Line Check Valve will prevent backflow on your irrigation system. 

Please let us know if you have further questions about your project.

Mitchell