Colorado winters are hard on irrigation systems. One of the most important steps a property owner or manager can take before freezing temperatures arrive is making sure the irrigation system is properly winterized.
Unfortunately, simply connecting an air compressor and “blowing out the sprinklers” does not necessarily mean the system has been adequately protected.
Why Proper Winterization Matters
Water expands when it freezes. Any water left behind in irrigation components can freeze, expand, and damage the system. That damage may not become obvious until spring startup, when cracked pipes, damaged valves, leaking fittings, broken heads, or failed backflow components begin showing themselves.
On a large commercial or multifamily property, those repairs can quickly become expensive.
Proper winterization is intended to remove enough water from the irrigation system to significantly reduce that risk. Doing that correctly requires more than just air pressure—it requires sufficient air volume, proper access points, and an understanding of the irrigation system itself.
Not Every Connection Is a Proper Blowout Point
One common mistake is trying to winterize a large irrigation system through a small test port on the backflow preventer.
Backflow test ports are designed primarily for testing the backflow assembly. They are not necessarily designed to deliver the volume of compressed air required to properly winterize a large commercial irrigation mainline.
A small opening may allow air into the system, but that does not mean enough airflow is reaching every portion of the system to adequately evacuate water.
This is especially important on properties with:
- Large-diameter mainlines
- Long irrigation runs
- Multiple zones
- Elevation changes
- Extensive drip irrigation
- Large numbers of valves and sprinkler heads
A properly located, appropriately sized blowout connection downstream of the backflow assembly can make a substantial difference in how effectively the system can be winterized.
More Pressure Is Not the Answer
Another misconception is that increasing compressor pressure will compensate for an inadequate connection.
It will not.
Irrigation winterization depends heavily on air volume, measured in cubic feet per minute (CFM), rather than simply increasing PSI. Excessive pressure can actually damage irrigation components.
The goal is controlled airflow through the irrigation system—not forcing extremely high pressure through it.
Existing Irrigation Problems Can Prevent Proper Winterization
Winterization is also more difficult when the irrigation system already has unresolved repairs.
Broken valves, leaking fittings, damaged quick couplers, compromised backflow assemblies, open lines, and other defects can interfere with the contractor’s ability to properly pressurize and evacuate portions of the system.
That is why irrigation repairs identified before winterization should be taken seriously.
Choosing not to complete recommended repairs can mean portions of the system cannot be properly winterized, increasing the likelihood of freeze damage.
Improper Winterization May Not Show Up Until Spring
One of the frustrating things about freeze damage is that everything may appear fine during the winter.
The real problems often appear during spring startup.
A system that was inadequately winterized may suddenly reveal:
- Cracked lateral or mainline piping
- Split fittings
- Damaged valves
- Broken sprinkler heads
- Leaking backflow components
- Failed quick couplers
- Underground leaks
- Reduced system pressure
Because many of these components are underground, finding and repairing the damage can require extensive troubleshooting and excavation.
Commercial Properties Require a Different Approach
Large commercial, HOA, multifamily, and municipal irrigation systems should not necessarily be treated like residential sprinkler systems.
Pipe diameter, property size, irrigation design, elevation, available blowout connections, and compressor capacity all matter.
A professional irrigation contractor should evaluate the system and determine the safest and most effective method for winterization rather than relying on a one-size-fits-all approach.
Protect the System Before the Freeze
Winterization is ultimately about protecting the investment already made in the property’s irrigation infrastructure.
Before winterization, property managers should address known irrigation repairs, make sure appropriate blowout connections are available, and work with a contractor that understands the airflow requirements of commercial systems.
A few preventative steps in the fall can prevent a much larger repair bill in the spring.
At Elevate Landscapes, our team evaluates irrigation systems before winterization and documents conditions that may prevent proper blowout or create additional freeze risk. Our goal isn’t simply to get air through the system—it is to protect the irrigation infrastructure as effectively as possible before Colorado’s freezing temperatures arrive.
Have questions about your property’s irrigation winterization or whether your system has an adequate blowout connection? Contact Elevate Landscapes before the first hard freeze.
