The winter is the ideal season for checking out all the different components of your irrigation system. It may be stating the obvious, but from my over 20 year's worth of experience as a professional gardener in a hot dry country, many people tend to forget about it during the rainy season, only to wake up in a panic at the first sign of hot weather in the spring. So make a commitment to go through the system 8 weeks or so before the onset of spring. Let's see then what has to be done, section by section.
Underground lawn sprinklers
Firstly open the tap to see which sprinklers if any are not working properly. Underground or pop-up sprinklers can sometimes sink somewhat in the ground. Adjust the height of the whole housing if necessary, even if that involves some digging to do so. Modern sprinkler heads have small filters inserted in the housing. Clean out each one. Three minutes work per unit can save a lot of frustration later, as part of the grass browns off in the summer, due to poor water coverage. It's also important to check the state of the nozzles. They become worn over time, and should be replaced every 3-5 years.
Drip irrigation
Irrigation drippers tend to get blocked in time. Switch on to see which ones are not emitting water. If the drippers are pre-set in the pipe by the manufacturer, then insert a "button" dripper next to the blocked up units. To reduce blockages in the future, it is essential to flush out the lines at least once a year. After turning on the tap, simply open the end of the line and let the water flow for about 5 minutes or so. The life span of dripper lines is usually up to 10-15 years, as mineral deposits in the water eventually make the line inoperable. However, neglecting to periodically wash out the system will significantly reduce their operable life span. I've seen drippers block up after 3 or 4 years when this simple routine task is ignored.
The Irrigation head unit
A professional irrigation system will include a controller, or timer, filters and pressure regulators. Needless to say, wash out the filters thoroughly. A dirty filter reduces the water flow rate, resulting in reduced pressure to the sprinklers, and blockages in the dripper lines. The operating efficiency of the pressure regulators should also be checked. These are vital for ensuring that the drip system is operating at the prescribed dynamic pressure, which is something between 1-2 Bars for a home unit. You may need professional assistance in this, but don't neglect the task, because high operating pressure can cause the connections to come away and even to burst. Replace batteries where necessary.
Finally, spray oil on all the metal parts of the unit. What a pain it is to try and unscrew a fitting attached to the wall, only to find the screws are totally rusted! As a very great comic actor and writer once said - "Silly little point but it does seem to matter!" I wonder if you know who that might have been.
