MAIN MENU

Technical Guide to installing drip irrigation

Sketch a plan to a simple scale, outline the area to be irrigated and include the position of pathways, walls and any other obstacles. Indicate location of water source.

Water Flow Test

Remove fittings from the tap to be tested, turn tap on full and place a bucket underneath. Time how many seconds it takes to fill the bucket. With this test you can calculate the approx number of drippers that can be operated at the same time.

To calculate your flow rate, record the number of seconds it takes to fill a bucket (eg. say a 9 litre bucket takes 12 seconds) and divide that into 60 (60 ÷ 12 = 5). You now have 5 'buckets' per minute. Multiply the number of buckets per minute by the volume of the bucket use. i.e. 5 buckets per minute x 9 litres = 45 litres per minute.

Designing the Drip System

Drip irrigation consists of drip emitters that release a small, controlled amount of water. Drippers come in different forms; 1. A drip emitter or dripper spike, which is connected to supply line using spaghetti tubing. This method is suitable for irregular or sparse plant spacings so that water is delivered directly to the plant. 2. Uses a drip line, where drippers are pre-installed within the poly tube itself. This is suitable for large ground cover areas, densely populated garden beds or narrow plant rows.

Drip emitters come with different flow rates to allow more water for thirstier plants. 2, 4 & 8 l/h drippers used correctly will ensure the correct proportioning of water between different plant types/sizes. The drippers come with 4mm barb fittings that are compatible with existing micro spray system tubing.

Drip line is currently available in 13mm, 6mm and 4mm ID diameters with various spacings between emitters from 30cm down to 15cm depending on the brand and size used. Pressure compensated and non-pressure compensated drip lines are available in the 13mm size tubing. Pressure compensated is used for hilly and sloping areas to distribute water evenly, throughout the garden. 13mm Non-pressure compensating drip line is suited to flat terrain. A patch of wetted soil of about 30 cm surrounds most drippers depending on soil type. Drippers should be laid at the base of plants to ensure water delivery to the plant root ball.

• Use normal polytube between tap and start of dripline
• Connect poly tube to the tap using a nut & tail fitting.
• Install poly/dripline above ground in garden and cover with mulch if desired
• Clamp all fittings before testing system.
• FLUSH out the system prior to the installation of the flushing valve. **
• Fold over the end of the tube and temporarily secure with tape or wire.
• Test system turning on the tap just a little to allow the air to release and the pipe to pressurise.† ( refer air release valve installation )
• Only turn the tap on just enough to ensure all drippers on the line are working. A ( PRV ) pressure regulator device is recommended once systems are operational.
  

Drip line Flow Rate:

N.B. Up to 200m of drip line can be run at once depending on the available flow and the width of wetted soil will depend on both soil type and dripper spacing.
*P/C. is pressure compensated drip line which distributes evenly over sloping areas.
**Flushing Valve is installed at end of line or lowest point.
† An air release valve installed at the highest point in the line prevents suck back of outside debris by breaking the vacuum caused when water drains to the lowest point in the line

For information on the current water restrictions, please visit the Sydney Water website www.sydneywater.com.au. For information on approved drip irrigation methods follow the links to drip irrigation.

PRINTER FRIENDLY VERSION