How to plan an irrigation system

The first step in planning an irrigation system is to draw up a plan of your garden. This will help you to decide what type of irrigation system will work for your space and where it should be installed.

The main things to include in this plan are:

• Water supply access
• Areas of your garden and lawn that need irrigation
• Power supply
• Any structures or features that can’t get wet or that might get in the way of it being installed.

A drip system uses drip emitter tubes underground that deliver water directly to the plants’ roots. When using drip systems, space your tubes 30cm apart to ensure the soil doesn’t dry up, which can stunt root growth.

Sprayer irrigation mimics rainfall by using sprinklers to water the plants and the soil surface. Pop-up systems are similar to sprayers, but they are buried underneath the turf's surface and are completely hidden until turned on.

For sprayers or pop-up irrigation, it’s important to have a minimum of 50 percent spray overlap to ensure areas are properly watered.

The next step is to test your water pressure. Checking this is important because if you have high-pressure flow, you’ll need to put a pressure reducer on your tap to reduce it.

To get an accurate water pressure reading, hook a pressure gauge onto a tap. You can also use a manual technique. Grab a bucket, turn your tap onto full pressure, and then count the number of seconds it takes to fill up the bucket. Divide the size of the bucket (in litres) by the seconds it took to fill it and multiply by 60. (Bucket size ÷ time in seconds x 60.)