From Sprinkler to Drip Irrigation
With 3a and even now with level 2 water restrictions, there are mandatory changes to the way we water our gardens, from the sprinkler system to the drip system as graphically illustrated below.
 

Above ground sprinklers, whether pop up or fixed head, distribute either a jet of water along with spray or a fixed arc of spray over an area of garden. For the vast majority of people with a sprinkler system, they ran off mains water and were broken down into small zones around the property. Some of the reasons for zoning the system were: water pressure not being sufficient to run the whole system at the same time and some zones having different watering requirements than others.

It had always been recognised that there were many inefficiencies in the spray system of watering and the drip system had always been a less popular option. It’s only since the current drought and the water restrictions that drip irrigation has risen to dominance.

Some of the problems often associated with the spray system are:

• Misting
• Wind drift
• Overspray
• Water runoff onto paths and roads
• Easily broken
• Puddling
• Many areas were watered that didn’t need as much water as other parts of the same zone and.
• Easily vandalised, particularly in public areas

The drip system, whilst not perfect, did overcome most of these inefficiencies of the spray system and introduced some efficiencies not mentioned above. For example:

• Reduces evaporation due to the drip line being under the mulch (ideally)
• Reduces weed growth by not putting water in areas not requiring water
• Totally eliminates the wind drift issue
• Avoids run off because the water is emitted so slowly that it has a chance to soak into the soil rather than pool and run off
• More efficient for the same reason when irrigating sloped areas
• Eliminates the overspray problem because there is no spray
• Reduces water consumption when designed correctly and the right run times are programmed.
• Delivers water directly to the root area of the plant where it’s needed the most
• Reduced vandalism because it’s out of site

Under level 2 water restrictions you are allowed to irrigate your garden using drip irrigation methods but only in your allocated times and days of the week.

For those with other sources of water, drip lines can be used to irrigate lawn areas (as long as you install them before the lawn is laid) by running drip lines under the ground and at a depth that efficiently provides water to the roots.

One of the arguments against inline drip systems is that the emitter holes are spread evenly along the hose and many people run the dripper hose from one part of the garden to the next over areas that don’t need water.

Another is that you can’t see whether the drippers are working or not like you can with sprinklers.

However, there are ways around these problems: firstly instead of installing inline dripper tube, use Low Density Polyethylene (LD Poly) hose and have individual drippers only at each plant or have Miniscape (which is a 6mm inline drip tube) coming off the LD Poly at the point closest to the plants.

You should also schedule an annual check of your drip system to ensure every part is working correctly.

As dripper systems don’t need nor can be run on the high water pressure of the mains, pressure reducers are used to reduce the mains pressure down from the 600Kpa to 800Kpa range to the 180Kpa to 300Kpa range.

Other components of the drip system include the air release valve, which is used at the highest point of each zone in order to prevent a vacuum occurring when the water is turned off in the zone and water flowing out of the lowest positioned drippers.

There’s the flush valve, which is normally placed at the lowest or end point of the zone to flush out any impurities that have found their way into the tubes and there is the filter which does the job of reducing impurities getting into the system in the first place.

Some dripper hose layouts are shown in the diagram to the right.

New Water Efficient Sprinkler Nozzles
In recent times, irrigation component manufacturers have introduced more efficient watering nozzles that are fitted to the top of pop ups and risers that use up to 30% less water and provide lower precipitation rates thus reducing many of the pitfalls of  the traditional spray heads.

Keep in mind that these are still banned under 3a water restrictions but can still be used when using other sources of water.
This is particularly good news when using water from tanks because your water will last longer due to the lower flow rates of these new nozzles.

Planning your Irrigation System
Our suggestion is that you let us help you.

The first option is to have Wave Irrigation come and provide you with a quotation on designing and installing an irrigation system for your property, be it your home or commercial property.
Whether it be a new system or converting an existing system to a drip system we can provide you with an obligation free quotation to do the work for you.
Just call us on 9808 4067 to have a preliminary discussion about your needs.

The second option is for those with the time and ability of doing the job themselves, with the help of our friendly staff in any of  the Wave Irrigation shops. With our assistance in planning the projects, understanding components required, tips and ideas as well as pitfalls to avoid, we can help you to achieve an efficient irrigation system.

If you choose to do it yourself then we recommend that you take the following steps:

If you are sourcing your water from water tanks or some other source other than mains, then skip step 1 below and replace it with the specifications and details of your pump, tank , pipes sizes and lengths or anything else related to your source of water.

Step 1. Calculate the amount of flow available at your Tap(s).
We will assume that most people don’t have a pressure gauge test kit so we will describe how to use the bucket method which everyone can do.

• Conduct the test at a time that you would normally be turning your system on (i.e 6am to 8am)
• Make sure all other taps and appliances are turned off
• Place a normal 9 litre garden bucket under your tap and with a watch with a second hand at the ready, turn the tap on fully and time how long it takes to completely fill the bucket. Repeat the same test for other outside taps that could be used as the source of water for your system.
   

Step 2. Download the Irrigation Planning sheet PDF on this page

• Print out the planner, preferably on A3 size, otherwise A4 will suffice.
• Draw your property boundaries using as much of the page as you can.
• Use a scale of either 1cm = 1m or 0.5cm = 1m. The first is most desirable as long as it fits on the page. Alternatively you can join two pages together with tape.
• Measure and draw all your buildings on the plan
• Measure and draw your garden beds and paths on the plan
• Measure and draw where your taps are located on the plan
• Roughly calculate the slope(s) of the land and note them on the plan
• If you are sourcing water using a pump then draw on the plan where your tanks and pumps are located
• On your plan mark where your plants are located and if possible provide the details of the type of plants they are.

Step 4. Purchase your components
Whether we draw up your plan or you do it yourself, we can then supply you with the components to suit your plans. If you have done it yourself we will do a final check to make sure it will work efficiently for you.
At the same time we will give you the necessary guidance on how it’s done.

Step 5. Install you irrigation system.
It’s over to you now but if you are doing the work during our open hours and you run into a problem, give us a call and one of our staff will try to help you on the phone.


If you want to do it all yourself and are just looking to find comprehensive information about planning an irrigation system then here are a couple of our supplier’s websites with that sort of information.