A Crash Course in Restarting Irrigation Systems
|By DANNY FASOLD|
So it’s already January and things are cold, wet and winter-whitening chilly and a nice hot cup of coffee is just what the doctor ordered. And best to drink up now, recharge those batteries and get ready to kick things into high gear, because—cold as things are now—spring is just around the corner, and there’s work to be done.
Not the least of which is starting up your clients’ irrigation systems once again. If you’ve done your job, these systems should be in hibernation at the moment, pumped dry and lying in wait for that first wave of warmth to bring in the new season. Many landscape contracting companies will wait until the beginning of April before turning their irrigation systems back on because they don’t want to run the risk of starting them up too early leaving them vulnerable to freezes. Those with a like-minded attitude should do the same.
But before you do, there are several precautions you must take. First, you should make absolutely sure that the soil in which the irrigation system is entrenched is frost-free. You can do this by taking a shovel or a spade and digging about 12 inches deep into the ground. If there are signs of frost there, the best thing to do would be to hold off another few weeks before restarting the system as the weather hasn’t quite yet warmed to a comfortable level.
Replacements and repairs are very common when restarting a system. You certainly wouldn’t want to leave the system running with cracked pipes or faulty sprinklers, so you might find it handy to bring some back-up tools and accessories with you when turning a system on. Fittings, risers, sprinkler heads, nozzles, extra piping, primer and cement are just some of the things you will want to have available in case they’re needed. You might not end up needing them at all, but if repairs do need to be made, having them readily available prevents you from having to make repeat trips to the same site. Always check for leaky valves, clogged emitters and calcium buildup on sprinkler nozzles. Rather than cleaning plastic sprinkler nozzles, you might want to consider replacing them, as cleaning them leaves small scratches that can throw off your system’s spray patterns, creating dry spots.
Performing repairs not only strengthens the system, it’s also a great way to pull in extra revenue. Whatever replacements or repairs that are made will be charged to your client.
During the winter, it’s not uncommon for animals to burrow down and take up residence in your irrigation system. Small critters such as moles, mice and other rodents are especially prone to crawling down into piping systems. How they manage to squeeze in is their business, but it’s your job to get them out before you turn the system back on. If your system has a rodent problem, open up the ends of the tubes and flush them out simply by turning on the water.
One of the most important things to look out for is the water hammer, which occurs when a damaging surge of pressure bursts out of the pipes, resulting from a rush of water flowing through the system all at once. The water hammer can create massive geysers of water and air which spill out onto the turf and damage the pipes along the way. This can obviously be detrimental to the integrity of the system.
To avoid a water hammer, you should undertake a series of careful procedures. First, if the irrigation system isn’t equipped with relief valves or drains, remove the sprinkler heads located at the highest point of each zone. This pushes the air that is inside the pipes outside of the system during the refilling process. Once this is done, you can begin filling the system’s main line with water. It should be located between the water source and the zone valves. It’s important to turn the shutoff valve very slowly. About a quarter of a turn should do the trick. The main line controls the water supply of the entire system, so play it easy and take your time, refilling the line slowly so as not to create a pressure surge that overwhelms the system.
Once the main line has been filled, slowly open each zone valve so you can fill the rest of the zones. Make sure that you consult the instruction manuals that go with the valves, as valves tend to open in slightly different ways, depending on their manufacturer.
Once the water stops pouring out of the open risers, close each zone valve. Don’t be surprised if it takes as long as 30 minutes to refill each zone.
When the zones have been completely refilled, it’s time to take your reawakened and refreshed irrigation system for a test drive. We recommend running each zone for around two minutes to flush out any remaining air and to make sure the automatic timer is working properly. This is also a good opportunity to assess the distribution levels of the sprinklers. You’ll want to watch to see that the water is landing where it’s supposed to and not on windows, cars or streets. If there’s a problem with distribution, you’ll want to realign the sprinkler heads until the water coverage is uniformly distributed throughout the lawn.
You’ll also want to check the controller to see if watering schedules are set to come on in a timely manner. If the client is using a drip system, check to see that every emitter is transmitting water to the rootzone in correct proportions. When you’re sure that everything is running smoothly, you can finally open the main supply valve to the full operating position.
Once you’ve completed these steps, take a swig from your thermos and give yourself a big pat on the back. Your irrigation system has been restarted and is running smoothly again! Okay, don’t pat yourself too hard now. You’ll be back here before you know it, this time to winterize the system.