How to Winterize Irrigation Systems for Lawns in Colorado
- Bath Landscape
- Oct 7
- 4 min read
You’ve worked hard and now your lawn looks great! Don’t let our Colorado winter destroy all of that overnight. Everyone remembers from science class that when water freezes, it expands. We’ve all also experienced this in our own freezer. And while a few freezer mishaps won’t destroy your home appliance, even one mistake with a frozen pipe can destroy your irrigation system. Winterizing your lawn irrigation systems before the first freeze will save your lawn and your wallet come spring. Read on to learn the process and all about how Bath Landscape & Irrigation can check this task off your list.
Shut Down the System
First, turn off the water supply to the irrigation system at the main valve, usually located near your water meter or where the irrigation line branches from your home's water supply. Turn off this valve carefully, without forcing it.
Drain the Water
There are three main methods for removing water from the system:
Manual Drain Method
Automatic Drain Method
Blow Out Method
All three are described below, but experts agree that only the blowout method will consistently provide the best results. This is because manual and automatic drain valves rely on gravity, but underground pipes shift over time, and you can't visually confirm complete drainage, whereas the blowout method uses compressed air instead. Compressed air is the only reliable way to remove all water, especially from electric valve systems where water sits on top of valve diaphragms.
Manual Drain Method: If your system has manual drain valves (typically at low points), open all of them and let gravity drain the water. You'll also need to open drain caps on sprinkler heads if present.
Automatic Drain Method: Systems with automatic drain valves will drain themselves when pressure drops below a certain point (usually 10-15 PSI). Simply shut off the water supply and let the system drain naturally.
Blowout Method (recommended): The blowout method involves using compressed air to force all water out of the lines. You'll need an air compressor capable of producing 50-80 CFM at 50-80 PSI. Connect it to the system through a blowout fitting, then systematically blow out each zone, starting with the highest elevation and working down. This is the most thorough way to remove all of the water from your system.
Wearing protective safety gear is a must with the blowout method because there is a real danger to your body when using compressed air. Most experts agree that because of the high risk of injury and the technical aspects of both the equipment and the process, it is highly recommended that an experienced professional perform the blowout method of winterization.
Winterizing Backflow Prevention Devices
After you or the professional has completed the blowout step of the process, the next step is to winterize the backflow prevention device.
Turn the ball valves on the backflow preventer to a 45-degree angle relative to the pipe, and give the screws of the test-cocks a ¼ turn, where they are also at a 45-degree angle. This allows for any trapped water remaining in the valves to drain out and to prevent any cracking due to freezing. Make sure to insulate any exposed, above-ground pipe by applying foam around the pipes or by purchasing a backflow blanket to insulate the backflow device.
System Protection Tips
Leave all backflow preventer valves half-open to prevent freezing and splitting.
Locate the drain valve (which should be close to the water shutoff valve), open it, and drain any remaining water from the system. Then, leave the drain valve open during the winter (remember the water valve should remain off during the winter). You can put a large bowl or bucket on the floor to catch any water that may drip from the drain. After all of this is finished, you’ll want to be certain that your irrigation controller is in the off position.
Remove any above-ground components that could freeze and store them indoors. This includes hose-end timers, pressure regulators, and removable backflow preventers.
Safety and Professional Considerations
Always wear safety protection during blowout procedures. High-pressure air and debris from sprinkler heads can cause serious injury!
While homeowners can perform manual draining, the blowout method requires proper equipment and technique. Many people hire professionals for this service to protect against expensive freeze damage repairs.
Timing
Start the winterization process after your last watering but before the first hard freeze. It’s much less costly to properly prepare your irrigation system in fall than to repair damaged pipes and valves in spring.
Get Ready for Winter and Protect Your Irrigation System
The first freeze could be the last time your irrigation system works. The key to a stress-free spring is a successful winterization by experienced professionals. When you hire us to handle this chore, you don’t have to worry about safety, the right supplies, or tinker with finicky faucets. Contact Bath Landscape & Irrigation for a trouble-free operation and relax this winter, knowing your irrigation system is protected and a beautiful lawn awaits in spring.
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