For automatic irrigators, starting up the sprinkler system in the late spring and shutting it down for the winter are annual rituals. Those living in warm climates may keep their sprinkler system running all year long. In places where the mercury drops below 32° F, winterization of your irrigation system is a must to avoid cracked pipes and broken heads (among other things). Here are some procedures for doing the job yourself.

Starting Up and Shutting Down Your Irrigation System

Winterization
Winterizing your irrigation system is really pretty simple:

1. Turn off the water to the irrigation system at main valve.
2. Set the automatic irrigation controller to the "rain" setting.
3. Turn on each of the valves to release pressure in the pipes.
4. Drain all of the water out of any irrigation components that might freeze.

These procedures will vary depending upon the climate (temperate vs. cold). Click here for a detailed explanation of these tasks.

Spring Start Up Procedures
This is just as important as winterization. When you first turn on your sprinkler or drip system in spring you should always flush it out. During the winter many small critters take up residence in your sprinklers, emitters, tubes, and pipes. Often they manage to squeeze in, only to be unable to get back out when spring comes.

To flush the system, open the ends of drip tubes and flush them out by turning on the water. For sprinklers remove the nozzles from, at the least, the last head on each pipe (better yet, remove them all) and run the water.

After flushing, check the system out by running it. Look for clogged emitters or nozzles. Replace clogged nozzles and emitters with new ones. Cleaning them leaves small scratches that mess up the spray pattern and create dry spots. (So that's often why you have more and more dry spots each year! Who would have known!

Calcium buildup on sprinkler nozzles can be removed using one of the many calcium remover products available for kitchen use.

Check for leaking valves. Often the flexible seals dry out over the winter and leak when the water is turned back on.

Finally, check the controller for proper run times for each station. If it has a back-up battery replace it with a fresh one. Almost all solid state controllers use ALKALINE back-up batteries and will not work right with other kinds- if in doubt use an alkaline type battery. The battery on some controllers is located behind a face plate where you can't see it, so if you don't see a battery, remove the wiring compartment cover and look for it in there. A few of the high-end controllers have built in battery chargers (look at the batteries, they should be labeled "rechargeable" if the clock has a built in charger). Some controllers now come with non-volatile program memory and don't need batteries.

Source:
www.irrigationtutorials.com (accessed 7/2/01)