The end of the season is upon us, so it’s time to talk about shutting down your irrigation for the year.

As winter approaches in Colorado, homeowners need to prepare their irrigation systems for freezing temperatures. Winterizing your sprinkler system is essential to avoid costly repairs caused by frozen pipes, valves, and other components. Colorado’s unpredictable fall weather, with its rapid temperature drops, makes it crucial to be prepared before the first freeze hits. Here’s a guide on how to winterize your irrigation system and the best time to do it.

Why Winterizing Your Irrigation System is Essential

In Colorado, winters are cold, and temperatures can frequently drop below freezing. If water is left in your sprinkler system’s pipes and valves, it can freeze and expand, causing pipes to crack or burst. A single damaged pipe can lead to flooding, water damage, and the need for extensive repairs when spring comes around. Properly winterizing your system ensures that it will be ready to operate again next season without problems.

When is the Right Time to Winterize in Colorado?

The best time to winterize your irrigation system in Colorado is before the first hard freeze. While the exact timing can vary depending on your location, mid to late-October is generally a good rule of thumb for most areas of the state, particularly in the Front Range and mountain regions.

Colorado’s weather can be unpredictable, with temperatures in the 70s one day and a freeze warning the next. It’s important to stay informed about the local weather forecast as the season changes. Even if the days are warm, nighttime temperatures can dip below freezing and cause damage to your irrigation system.

In the marginal time of October before the weather really makes a turn for the worst, you can eek out some more time running your system by shutting off the water supply and draining your vacuum breaker if it looks like temps are going to drop into freeze territory for the night. The inground components of your system are relatively safe until we get consistent freezing temps. It definitely requires some diligence and elbow grease, but you can gain yourself a little bit more time watering your landscape…..especially if you laid sod or planted late in the season.

How to Winterize Your Irrigation System: Step-by-Step Guide

There are a few methods for winterizing an irrigation system, but the blowout method is the most effective in Colorado due to the state's harsh winters. Here’s how to winterize your system properly:

1. Shut Off the Water Supply

First, locate the main shut-off valve for your irrigation system and turn it off. This is usually located near your water meter or in your basement, garage, or utility room. Shutting off the water supply will prevent more water from entering the irrigation system while you clear it out.

2. Drain or Blow Out the System

Once the water is off, the next step is to remove any water still in the pipes and sprinkler heads. In Colorado, the blowout method is recommended because it completely clears the water from the system, preventing freezing and potential damage.

To do this, you will need an air compressor:

• Attach the air compressor to the blowout port on your irrigation system. Most systems have a blowout port located near the backflow preventer or valve box.

• Set the compressor’s PSI to a safe level for your system, typically between 50 and 80 PSI depending on your system’s design. Too much pressure can damage the pipes or sprinkler heads.

• Blow out each zone individually by turning on the zone valve and letting the air push the water out through the sprinkler heads. You will see water and mist being expelled from the heads. Once the mist clears and only air is coming out, turn off that zone and move on to the next one.

• Repeat the process until all zones have been cleared of water.

3. Turn Off the Timer or Controller

After blowing out the system, make sure to turn off your irrigation system’s timer or controller. Some modern controllers have a “rain mode” or “off” setting that you can use during the winter months, which will preserve the settings while preventing the system from running.

4. Protect the Backflow Preventer

The backflow preventer is a crucial part of your irrigation system, and it needs protection from freezing temperatures. If it is exposed, consider covering it with insulation or a backflow insulation cover, which is readily available at most hardware stores. Be sure to check for any water remaining in the backflow preventer and drain it if necessary.

5. Insulate Any Above-Ground Components

If you have any exposed above-ground pipes or valves, insulate them to protect them from freezing temperatures. You can use foam pipe insulation, thermal tape, or specially designed insulation wraps to keep them safe throughout the winter.

Hiring a Professional vs. DIY

While some homeowners may feel confident doing the winterization themselves, others might prefer to hire a professional irrigation service. If you’re not experienced with the blowout method or don’t have access to an air compressor, hiring a professional is a wise investment. A professional will ensure the job is done correctly, minimizing the risk of damage. The cost of winterization services is typically much lower than the cost of repairing a damaged system in the spring.

Common Mistakes to Avoid

• Waiting too long: Don’t wait until snow is flying to winterize your system. By then, it may be too late, and freezing temperatures could already damage the pipes.

• Using too much air pressure: If you're using an air compressor, be mindful of the PSI setting. High pressure can damage your pipes and sprinkler heads.

• Neglecting the backflow preventer: Failing to drain or insulate the backflow preventer can lead to costly repairs.

• Not blowing out all zones: Make sure to clear each zone of your system. Missing one zone can leave water in the pipes, causing potential damage.

Winterizing your irrigation system is a crucial task for homeowners in Colorado, where freezing temperatures can cause significant damage to your system if not properly prepared. Mid to late-October is the ideal time to take care of this, and using the blowout method ensures that your pipes, valves, and sprinkler heads are safe from winter’s freezing temperatures. Whether you choose to winterize yourself or hire a professional, taking the necessary precautions will save you time, money, and stress when spring arrives.

By properly winterizing your system, you’ll protect your investment and ensure your irrigation system is ready to go next season, allowing you to keep your lawn and garden healthy year after year.