How Do I Winterize My Irrigation System?

“I’m fairly new to backyard farming and realize that winter is coming soon here in Ottawa, Canada. I have a relatively simple irrigation system installed that I’ve been using to water my crops and small orchard trees. I’ve read that I need to winterize it, but I’m not entirely sure why it’s necessary or how to go about it. Can you walk me through the process? I want to avoid any costly repairs come springtime, so any advice would be much appreciated.” Thanks, Bryan, Ottawa, Canada.

How Do I Winterize My Irrigation System?

Winter is fast approaching and, like Bryan, if you have an irrigation system set up for your backyard farm, you might be wondering how to prepare it for the chilly season. Properly winterizing your irrigation system is a key step in protecting your investment and ensuring that your system is in good working order when spring rolls around. Let’s go over everything you need to know about winterizing your irrigation system—from why it’s important to the step-by-step process you’ll need to follow.

Why Winterizing Your Irrigation System Matters

Before we jump into the detailed steps, it’s important to understand why winterizing is necessary. Bryan, you might be wondering why you should bother, especially if your irrigation system is functioning perfectly right now. The truth is, winterizing is more of a preventive measure that helps protect your system from potential damage caused by freezing temperatures.

Here’s why it matters:

• Prevent Pipe Damage: Water left in the irrigation pipes can freeze and expand during winter. This pressure can cause the pipes to crack or even burst, leading to costly repairs come springtime.
• Safeguard Valves and Sprinkler Heads: The small mechanisms within valves and sprinkler heads are especially vulnerable to damage from freezing water. Winterizing ensures these components remain intact and functional.
• Avoid Full System Replacement: The last thing you want is to discover that your entire system is beyond repair after winter. Winterizing increases the lifespan of your system by preventing extreme temperature damage.
• Save Money on Repairs: Repairing or replacing damaged pipes, valves, and other components can be expensive. By taking preventive measures, you’ll avoid hefty repair bills in the future.

When to Winterize Your Irrigation System

Timing is crucial when it comes to winterizing your irrigation system. Ideally, you should aim to do this before the first hard freeze, which is when temperatures drop below freezing for an extended period. For Bryan in Ottawa, where winters can get especially cold, timing is even more critical. A good time to winterize would be late October or early November, depending on the year’s weather patterns.

If you wait too long, freezing temperatures might catch you off guard, putting your system at risk. Keep an eye on the weather forecast, particularly for any sudden cold snaps.

How to Winterize an Irrigation System: Step-by-Step Process

Now let’s get into the nitty-gritty details. Winterizing an irrigation system is a job that can be done yourself if you’re comfortable with some basic tools and procedures. Below is a step-by-step guide to help you through the process.

Step 1: Shut Off the Water Supply

The first and most critical step in winterizing your irrigation system involves shutting off the water supply. This is typically done by locating the main valve that supplies water to your irrigation system.

Steps to Shut Off the Water:

1. Locate the main shut-off valve. This could be in your basement, crawl space, or near where the irrigation system connects to your home’s water supply.
2. Turn the valve clockwise to shut it off. Ensure that no water is flowing into the irrigation pipes.
3. If you have a backflow prevention device, ensure it is also turned off at this time.

Shutting off the water supply ensures that no more water enters the system during the winterization process, which is important to prevent any freezing.

Step 2: Drain the System

Now that the water supply is off, you need to ensure that there’s no water left in the pipes. There are three main methods for draining an irrigation system: manual drain, automatic drain, and the blow-out method. Each has its own set of procedures, and the right one for you will depend on the type of system you have in place.

Manual Drain Method

If your system uses manual drainage valves, you’ll need to execute the following steps:

1. After shutting off the water supply, locate the manual drain valves. These are typically found at the lowest points of the system.
2. Open each valve to allow water to drain from the pipes. Gravity will assist in emptying the water, but make sure to drain every section of the system.
3. Once the water has fully drained, close the valves.

This method can be straightforward, but you need to ensure you’ve drained every section; missing any part can result in frozen water causing damage.

Automatic Drain Method

Some irrigation systems come with automatic drain valves that will open on their own when the water pressure drops below a certain level.

1. After turning off the water supply, activate a zone in your irrigation system to release pressure. This action will trigger the automatic drain valves.
2. The valves should open automatically, allowing water to drain out.
3. Make sure to run through all zones to ensure that every part of the system gets properly drained.

Even if your system has automatic drain valves, it’s a good idea to double-check that all water has been removed from the pipes.

Blow-Out Method

This method is perhaps the most thorough but should be approached with caution. It involves using an air compressor to blast water out of the irrigation system. This method is recommended for complex systems or for those in areas with particularly harsh winters, like Bryan in Ottawa.

Important: Use caution with the blow-out method. If done incorrectly, it can cause damage to your irrigation system. If you’re unsure, it’s recommended to hire a professional to perform this task.

1. After shutting off the water supply, remove the backflow preventer (if applicable; follow your model’s instructions).
2. Attach an air compressor to the blow-out port on your irrigation system. Use a pressure regulator to keep the air pressure within safe limits (usually no more than 50 PSI for PVC pipes and 80 PSI for poly pipes).
3. Close all the valves except for one zone, starting with the farthest zone from the air compressor.
4. Turn on the air compressor and allow air to flow through the system, pushing water out of the sprinkler heads. Wait until only air (no water) is left coming out.
5. Move on to the next zone and repeat the process for all zones in your irrigation system.
6. Once done, disconnect the air compressor and replace any components you removed earlier.

The blow-out method usually provides the most comprehensive removal of water. Therefore, it’s the best option if you are particularly concerned about winter damage.

Step 3: Protect the Backflow Device

The backflow prevention device is crucial to preventing contaminated water from entering your home’s drinking supply. However, it’s also vulnerable to freezing temperatures and requires special attention during winterization.

Steps to Protect Backflow Devices:

1. First, shut off the isolation valves on the backflow preventer.
2. Open the test cocks on the backflow preventer to allow any water to drain out.
3. Once drained, leave the isolation valves and test cocks open through the winter to allow any remaining water to expand safely.
4. If possible, insulate the backflow preventer using insulating tape, foam pipe wrap, or even a specially designed cover.

In areas with extreme cold, like Ottawa, you may even want to consider removing the backflow device altogether and storing it indoors during winter.

Step 4: Insulate Any Above-Ground Components

While the focus is often on draining water from the below-ground pipes, don’t overlook any above-ground components of your irrigation system. This could include valves, filters, and even the main shut-off valve.

Steps for Insulating Above-Ground Components:

1. Wrap any exposed pipes and valves with foam insulation tape or a similar material to help prevent freezing.
2. Use a plastic cover or specialty cover for the valve control boxes to keep out moisture while still allowing some ventilation.
3. If you live in an area with particularly harsh winters, consider installing insulated covers designed for outdoor faucets and similar components.

This additional step is key to protecting the most vulnerable parts of your irrigation system from the cold.

Step 5: Test and Monitor

After completing all of the previous steps, it’s a great idea to conduct a final test or inspection before the cold really sets in. Make sure everything is secure and there are no leaks, and check to ensure that the entire system is prepared for winter.

Post-Winter Tips:

• Check the System Early in Spring: Once the weather starts to warm up, conduct a thorough inspection of your irrigation system to ensure everything is working properly.
• Gradually Turn on the Water Supply: When reactivating your system in spring, do so gradually. Avoid sudden pressure surges that could damage components weakened by the cold.

By taking the time to go through these steps, you’ll ensure that your irrigation system is well-protected and ready to run smoothly when the growing season starts again.

Common Troubleshooting Tips

No matter how careful you are, issues can sometimes arise during the winterizing process. Keeping that in mind, here are a few troubleshooting tips:

• Still Water in the Lines: Sometimes small amounts of water may remain in the pipes, even after draining. If you suspect this might be the case, consider using the blow-out method or repeating the manual drain process to ensure everything is clear.
• Low Air Pressure: If you’re using the blow-out method but aren’t seeing sufficient results, double-check that your air compressor is suitably powerful. The PSI should match what’s recommended for your specific irrigation system (50 PSI for PVC and 80 PSI for poly pipes).
• Frozen Backflow Device: If you discover that your backflow prevention device is already frozen, do not attempt to force it open. Instead, use warm towels or a gentle heat source to thaw it before proceeding.
• Insufficient Draining in Zones: If you notice that a particular zone did not drain fully or there’s still some residual water, check for any obstructions or faulty valves that might be preventing proper drainage.

If you’re still experiencing issues and need additional help, consider consulting with an irrigation specialist who can diagnose and fix any problems before the winter weather sets in.

Final Thoughts…

Bryan, taking the time to winterize your irrigation system, especially in a place like Ottawa where winters can be harsh, is crucial for protecting your investment in your backyard farm. From shutting off the water supply to ensuring every last drop of water is drained, these steps will help ensure that your irrigation system remains in excellent shape come spring. Thanks for reaching out with your question, and here’s to a smooth and problem-free winter for your backyard farm!