Spring starts on 1 September. Your irrigation system has been sitting still since about May. Grit has settled in the pipes. Seals have dried out. Something has probably chewed a hole in your poly line.
Most people find out the hard way. They flick the pump on in October. Then they lose a lawn or a row of seedlings while they chase parts.
Two weekends of checks now will save you that. Here is the order we tell customers to work in.
What Does Winter Actually Do to an Idle System?
The water that sits still goes bad. Fine grit drops to the bottom of the mainline. Algae and slime build up inside the drip tube. Both head straight for your drippers when you turn the water on. A drip water irrigation system suffers the most, because its outlets are the smallest.
The rest of the damage is easy to picture:
- UV turns exposed poly and fittings brittle
- Frost splits above-ground pipe in inland and tablelands areas
- Rats and mice chew poly line looking for water
- Pump seals dry and crack when the unit sits unused
- Rust locks up impellers and non-return valves
- Ants and soil block sprinkler nozzles
None of that shows up until you turn the tap on. So turn it on early. Do it now, not in a 35-degree week in November.
Step 1: Walk Every Zone Before You Touch the Pump
Keep the system off. Grab a roll of flagging tape and walk the whole run.
Look at the mainline, the risers, the drip tube, and every sprinkler head. Tape anything that looks cracked, chewed, wobbly or missing. Check where the pipe crosses a driveway or a bed edge. That is where damage hides.
Write the list on your phone as you go. One trip for parts beats four.
Step 2: Flush the Lines Before You Pressurise
Never send full pressure into a dirty system. You will push winter grit straight into your drippers and nozzles.
Open the end caps or flush valves. Run the system at low pressure. Let each line run until the water runs clear. Then close the caps one at a time. Start at the mainline and work out to the laterals.
Flush a drip water irrigation system last. Do one line at a time. Drip outlets are tiny, often 1 mm or less. One grain of sand blocks them for good.
Step 3: Service the Pump
Your pump does the work. Give it an hour before spring, not after it fails.
Petrol pump checks:
- Drain last season’s fuel. Stale petrol gums up carburettors.
- Change the oil and check the level on flat ground.
- Clean or replace the air filter.
- Pull the spark plug, clean it, and check the gap.
- Inspect the mechanical seal for drips at the shaft.
Diesel checks: change the fuel filter. Bleed air out of the fuel line. Charge the battery. Check the glow plugs on electric start units.
Then check the suction side. Most priming problems start there. Look for a cracked hose, a loose camlock, a missing gasket or a strainer packed with mud. Air gets in through any of those, and the pump loses prime.
Prime the pump. Run it for five minutes and listen. A good unit runs steady. Rattle, shake or a drop in flow means more work.
Is the pump past saving? Replace it now, while stock is good. Thornado stocks water transfer pumps built for this job. You can pick up a 3-inch diesel unit at 7HP, or a 4-inch at 10HP, both with electric start and a large fuel tank. Every Thornado pump comes with a 12-month warranty. Delivery is free on orders over $200 ex GST.
Step 4: Clean the Filters and Check Your Drippers
A drip water irrigation system lives or dies on its filter. Most drip lines need a 120 mesh screen, which is about 130 micron. Pull the element out and rinse it. Hold it up to the light. Replace it if you see splits or worn edges.
Now check the drippers. Run the line and watch each one for a few seconds. Look for three faults:
- No flow. The dripper is blocked, or the line has an air lock.
- Spraying instead of dripping. The dripper has split, or the barb has popped out.
- A dribble after shutdown. A check valve or the pressure reducer has failed.
Lime scale is the usual cause in hard water areas. A citric acid flush clears it. Slime and algae need a chlorine flush, then a long rinse with clean water. Never poke a wire into a blocked dripper. You will widen the hole and ruin the flow rate.
One more thing people miss. A drip water irrigation system usually runs between 100 and 250 kPa. Main pressure often sits well above that. Check that your pressure reducer works before you blame the tube.
Step 5: Sprinkler System Installation Checks and Coverage
Run each sprinkler zone for two minutes and stand there watching it. You cannot fault a zone from the shed.
Work through the heads one by one:
- Clean the nozzle and the filter basket under each pop up
- Straighten heads that lean, and reset any that sit above soil level
- Reset the arc on rotors that have drifted
- Replace cracked bodies rather than patching them
- Look for a fine mist, which means pressure is too high
- Look for weak, short throw, which means pressure is too low or a line is blocked
Then run a catch cup test. Put empty tuna tins across the zone. Run it for 15 minutes and measure the water in each tin. The depths should land within about 10 to 15 percent of each other. A big gap means the spacing is wrong. That points to a sprinkler system installation fault, not a service one.
Good sprinkler system installation uses head to head spacing. Each head throws water as far as the next one. Skip that and you get dry rings and soggy patches. No controller can fix bad spacing, so get the sprinkler system installation right and the season looks after itself.
Step 6: Replace the Small Parts That Fail First
Fittings cost a few dollars. A failed fitting at 2 am costs you a garden bed. Keep spare irrigation and plumbing supplies on the shelf, so one small crack never stops a watering run.
Check and replace as needed:
- Poly compression fittings that have gone chalky or brittle
- Camlock gaskets that have flattened or gone hard
- Ball valves and gate valves that have seized partway
- Foot valves and strainers with damaged mesh
- Non-return valves that let water drain back
- Layflat hose with splits, pinholes or worn couplings
- Pipe clamps that have rusted through
Thornado carries the full range of irrigation and plumbing supplies for this job, including poly compression fittings, ball valves, foot valves, camlock fittings and layflat hose. Buy your irrigation and plumbing supplies from one supplier. The threads and sizes then match when you get home.
How to Install Irrigation System Lines You Are Adding This Spring?
Plenty of growers extend a run during the spring service. If you are asking how to install irrigation system lines properly, work in this order. Order your parts before you dig, not halfway through the job.
- Measure your flow rate
Time how long a 9-litre bucket takes to fill from the tap or pump outlet. Divide 9 by the seconds, then multiply by 60. That gives you litres per minute.
- Measure your pressure
Screw a pressure gauge onto the outlet and read it with the tap fully open.
- Plan zones by water need
Group lawn with lawn, and vegetables with vegetables. Never mix sprinklers and drip on one zone. They run at different pressures.
- Size the pipe to the flow
Undersized pipe robs pressure at the far end. Most home runs use 19 mm or 25 mm poly for the mainline.
- Keep each zone inside your pump output
Add up the flow of every head or dripper in the zone. Stay under what your pump gives at that pressure.
- Trench 200 to 300 mm deep for buried mainline, and deeper under driveways.
- Fit an isolation valve on each zone. In the future you will be grateful.
- Pressure test before you backfill
Cap the ends, run it up, and walk the trench looking for leaks.
- Flush the new line, then fit the emitters or heads.
That order works for a small drip water irrigation system in a veggie patch. It works for a long lateral out to a paddock too. Only the pipe size and the pump change. Follow it, and you now know how to install irrigation system lines that still work in five years.
Step 7: Set the Controller for Spring, Not Summer
Deep and less often beats short and daily. Long soaks push roots down. Deep roots survive January.
Start your cycles between 4 am and 6 am. Wind and heat are low then, so you lose less water. Build run times up slowly through early spring. Do not jump straight to summer settings. Fit or reset a rain sensor, so the system skips a wet week.
Check your council or water authority rules first. Watering rules change from region to region, and they change from year to year.
Your Pre-Spring Checklist
Print this and tick it off:
- Walk every zone and mark faults
- Flush the mainline, then the laterals
- Service the pump and check the suction side
- Clean or replace the filter element
- Test the drip water irrigation system and clear blockages
- Check the pressure regulator
- Run each sprinkler zone and watch it
- Run a catch cup test
- Replace brittle fittings, gaskets and valves
- Order any irrigation and plumbing supplies you are short of
- Pressure test any new lines before backfilling
- Reset the controller and the rain sensor
Get the Parts in One Order
Chasing four suppliers for one fitting wastes a weekend. Thornado ships pumps, hoses, valves, nozzles and irrigation and plumbing supplies from one warehouse in Ingleburn, NSW. Dispatch is fast, right across Australia.
You get a 12 month warranty, a 30 day money back guarantee and free delivery on orders over $200 ex GST. Trade accounts suit approved applicants, and bulk order pricing applies to farms, contractors and councils.
Not sure which pump suits your flow and head?
Call the team on (02) 9600 8883 or email sales@thornado.com.au. Browse the full water pump range and get set before the first hot week arrives.