How-to
Freeze prep for commercial irrigation systems
Updated · Glossary
Before a hard freeze in Dallas–Fort Worth, turn the irrigation controller off and insulate the backflow preventer. If the freeze will last more than a night, shut the system off and drain it too. The backflow preventer is what breaks most often because it sits above ground, and a cracked one means no water to the system until it’s replaced. Sometimes it means a flooded meter box as well.
Before the freeze
- Turn controllers off or to rain mode. Watering before a freeze puts ice on sidewalks and streets, and a lot of cities ban it. A working freeze sensor helps, but don’t rely on it alone.
- Wrap the backflow preventer in an insulated cover or bag made for backflow devices. Towels and trash bags get wet and freeze to the pipe.
- For a long freeze, close the irrigation isolation valve and open the test cocks on the backflow preventer to let the water out. In a multi-day freeze, this is the step that saves the device.
- Insulate any pipe above ground, whether it’s at the backflow, at pump stations or on bridges.
- Know where your shutoffs are. If a pipe breaks at 2 a.m., somebody has to know which valve to close.
After the freeze
Don’t turn the system back on until everything has thawed, including the ground around the backflow. Close the test cocks first, then open the isolation valve slowly.
Then run each zone and walk it. You’re looking for broken heads, split pipe and water bubbling up where it shouldn’t. If the power went out, check the controller’s date and time.
Who does what
| Task | Property manager or HOA | Irrigation contractor |
|---|---|---|
| Know where shutoffs are | Yes | Yes |
| Turn controllers off before a freeze | Can do it | Usually handles it |
| Insulate and drain backflow preventers | Often hands off | Yes |
| Restart and walk the system | Hands off | Yes, a Licensed Irrigator |
| Repair freeze damage | No | Yes |
In Texas, repairing someone else’s irrigation system takes a TCEQ license. A backflow preventer damaged by a freeze also often needs a new test by a certified tester before the system goes back in use. Have your contractor handle both.
Common questions
Should I run my sprinklers before a freeze?
No. Water on turf and sidewalks before a freeze turns to ice and becomes a slip hazard, and many DFW cities ban irrigation in freezing weather, so turn controllers off or to rain mode.
What part of an irrigation system breaks in a freeze?
Most often the backflow preventer, because it’s above ground. Exposed pipe, valves at pump stations and shallow lines can crack too.
How do I protect a backflow preventer from freezing?
Wrap it in an insulated cover made for backflow devices. For a freeze longer than a night, also close the irrigation isolation valve and open the test cocks to drain it.
Who should turn the irrigation back on after a freeze?
Your irrigation contractor. Turning it back on means checking for damage zone by zone, and in Texas repairs have to be done by a Licensed Irrigator.
We have a Licensed Irrigator on staff, and freeze prep, controller scheduling and repairs are part of our irrigation service. Request a proposal if you want us to take it off your plate.