Just turning off your sprinkler system to deal with drought could be an expensive mistake! Before you unplug that sprinkler controller/timer or switch it to “rain mode” consider what precautions you should take if you don’t plan to run your sprinklers for an extended period of time. To be brief, all kinds of expensive-to-fix things happen to sprinkler systems that are not operated for a period of a year or more.
Fortunately there are a few precautions you can take to reduce these problems:
- The best solution is don’t completely shut off the system. Instead, run each of your sprinklers zones for 2 minutes once each month. This will keep the system in “operating condition.”
- A less desirable solution is to “Winterize” your sprinkler system, just like people in cold climates do each year before shutting the system down for the winter. Honestly this is probably not a practical option for most people. See the article on “How to Winterize Your Sprinkler System.”
- When you do return to regularly watering again, give your sprinkler system a “tune-up.” See the detailed step-by-step instructions at “How to Give Your Sprinkler System a Tune-Up.” This will get your system back to “like new” operating condition.
For more details, in-depth suggestions, and answers to most common questions regarding extended shut down of sprinkler systems continue reading…
Why Not Just Turn the Sprinklers Off?
Bad stuff happens to your sprinkler system when it is shut off for long periods of time. Roots will grow into the sprinklers, insects will crawl into them and lay eggs or get stuck. Stagnant water in pipes will grow algae which will gum up the sprinklers and ruin them. Sprinkler seals and gaskets will dry out and crack. Dry dirt and dust works its way into the sprinklers. Some soils heave and crack as they dry out which can move and misalign the sprinklers. Valve diaphragms dry out and split.
As a quick disclaimer, I know of no research that has been done on the effects of shutting down a sprinkler system for extended periods of time. This article is essentially my thoughts and opinions based on my 35+ years of experience mixed with some common sense and a lot of educated guessing!
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As noted above I have a couple of options to suggest that are better than just shutting off your sprinkler system.
1. Continue to Run the Sprinkler System Once a Month.
Yes, it will take some water to run the system and the water applied won’t be enough to really help the plants much. If running sprinklers is flat out banned in your area, obviously you will not be able to do this. But if you can run the sprinklers, then running the system for a short time prevents a lot of the problems that can develop if the system is fully shut off. It moves the stagnant water out of the pipes, lubricates the seals and diaphragms, blows roots, dirt, and insects out of the system. It won’t help with soil movement, there is nothing you can do for that, you need to address that when restarting the sprinkler system when the drought is over.
It is best if you can run each sprinkler valve zone manually so you can observe it in case anything has broken and needs to be fixed. You really should be checking your sprinklers each month for problems anyway, so this should actually be something you have scheduled already! If you have a “geyser” from a broken sprinkler or pipe the system will not be operating correctly and the benefits of running it are more or less lost. Plus a geyser wastes water and we are trying not to do that! So the best approach is to add a reminder to your calendar each month and manually run each sprinkler valve/zone.
That said, most people will forget to run the sprinklers, so if that is you then it is best to program your irrigation controller (timer, clock, etc.) to run the sprinklers once a month automatically. Most better quality sprinkler controllers can be set to water once a month. If yours can’t water monthly now might be a good time to consider a really nice “Smart Controller” that can automatically adjust the sprinkler system for you, to give you optimum watering times year-round.
Why run the sprinklers for 2 minutes? No real reason, that is just a good average amount of time it takes for a sprinkler zone to get up and running after the valve is turned on. You should run the sprinklers for long enough that they stabilize and are running smoothly. All the pop-up risers should be fully in the up position, and the sprinklers should not be spitting and spewing air that was in the pipes. You don’t want to run it longer than needed either, we are trying to use as little water as possible. So the best way to select the run time to enter into your controller program is to turn on the sprinkler valve for each zone and see how long each one needs to run for everything to stabilize. Then use that time. So you may find that the first valve needs 2 minutes, the second needs 3 minutes, the third needs 2 minutes, etc. Run each for the minimum amount of time it takes. Generally it takes at least 2 minutes to get the stagnant water out of the pipes so you probably don’t want to use less than 2 minutes.
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Why once a month? Again, really nothing more than a random number I arrived at based on years of experience. If given the choice I would prefer every 2 weeks. But I think that would use too much water and would violate the goal here, which is to save water. Once a month should be a good compromise. But if you want to run it every two weeks or once every 6 weeks, that is up to you… and of course you must follow any local regulatory agency’s rules. You don’t want to get slapped with a “water waster” fine.
2. Winterization of Sprinklers During Drought Periods
Winterization involves getting all the water out of the pipes and preparing your sprinkler system for freezing weather. But it can also be used to prepare the system for a total shut down during a drought. The various seals and diaphragms will still tend to dry out, and dirt and insects are still likely to get into sprinklers, thus winterization is not the best option by far. But it is better than nothing. The problem here is that in most areas subject to drought there is not a lot of frost, so sprinkler systems aren’t installed with drain valves, making it difficult to drain the water out. That means the water in the pipes needs to be blown out with air, but again few contractors in drought prone areas have the tools or expertise to do this. Homeowners can blow out some of the water using a home compressor, but the typical small garage compressor is not big enough to do a very good job, a lot of water will be left in the system. If you do want to try winterizing your sprinkler system there is a separate article that will show you how. “How to Winterize Your Sprinkler System.”
Restarting Your Sprinkler System
Once the drought is over you will likely want to restart your sprinkler system. If your system has been shut down for a year or more you should expect there will be problems. Even with precautions seals do dry out and dirt and insects may get in. Nozzles often get clogged up. Sprinkler heads get out of alignment. I suggest you give your system a “tune up” when restarting it. In areas where sprinkler systems are winterized people are used to this annual spring ritual of checking and restarting their sprinkler systems, and so the systems tend to get regular yearly maintenance. Here in drought susceptible areas we tend to irrigate most of the year and we often skip over this important yearly checkup… and with droughts and water shortages we should really be the ones keeping our systems in top shape! (Sigh. True confessions, I’m sometimes guilty of skipping over the yearly tune-up too.) Here’s an article on how to tune-up your sprinkler system: “How to Give Your Sprinkler System a Tune-Up.”