Protecting Your Sprinkler System From a Texas Freeze

Texas freezes are not the slow, predictable kind. They arrive fast, sit for a couple of days, and leave behind a lot of cracked irrigation parts. The good news is that most freeze damage is preventable in about fifteen minutes of work.

The part that breaks first

If something on your system is going to fail in a freeze, it is almost always the backflow preventer. It is the brass assembly mounted above ground, usually against an exterior wall, and it is the most exposed component you own.

Water expands when it freezes. Inside a sealed brass body with nowhere to go, that expansion cracks the housing or blows out the internal seals. Sometimes the crack is obvious. More often it is a hairline that does not reveal itself until the system pressurizes in spring and starts spraying.

That part matters more than people realize. A backflow preventer is not there for convenience. It stops non-drinkable irrigation water from siphoning back into your home's clean water supply. When it fails, that protection is gone.

What to do before the front arrives

You do not need special tools for any of this.

Shut the system off at the controller. Set it to off rather than relying on a rain sensor. A frozen sensor may not stop a scheduled cycle, and running sprinklers in freezing weather turns walkways into an ice rink.

Shut off water to the irrigation system. There is usually a valve near the backflow preventer or where the irrigation line branches off your main. Closing it means whatever water is still in the above-ground assembly is not under pressure and not being resupplied.

Insulate the backflow. Insulation tape, a fitted cover, or in a pinch a towel wrapped in a plastic bag and taped down. What matters is covering the brass body and any exposed pipe below it. Leave the small vents on the underside clear.

Drain what you can. If your assembly has test cocks or bleed valves, opening them lets trapped water out. If you are not sure which fittings those are, leave them alone and call somebody. Backing off the wrong fitting creates a different problem.

What to check once it thaws

Wait until temperatures are safely above freezing, then turn the water back on slowly and walk the system.

Look at the backflow assembly first, and look for water where there should not be any. Steady dripping or spraying from the body is a failed unit. Then run each zone one at a time and watch for heads that do not pop up, zones with obviously weak pressure, or wet spots appearing in the lawn. Any of those can mean a cracked line underground.

One thing worth knowing: a system can look fine and still have a slow leak. If your water bill jumps after a freeze and nothing else changed, that is often the first real symptom.

When to call somebody

Freeze damage is one of the few irrigation problems where waiting genuinely costs more. A cracked backflow will keep leaking treated water for as long as it is pressurized, and a cracked mainline will keep saturating your yard.

We are a licensed irrigator, license #18069, which matters here because backflow work is regulated in Texas and not every landscape crew can legally do it. Our repair pricing is flat rate and posted before we start, so you know what a repair costs before agreeing to it rather than after.

If your system took a hit, we would rather look at it early in the season than in the middle of the first hot stretch when everyone discovers their zones are not working at once.

Mistakes that make freeze damage worse

Letting the system run during the freeze. Some people leave a zone running on the theory that moving water will not freeze. On a Gulf Coast overnight freeze that is not reliable, and what you get instead is ice across the driveway and sidewalk. Turn it off.

Wrapping the backflow completely airtight. The assembly has vent openings on the underside that need to stay clear. Sealing the whole thing in plastic can trap moisture against the brass. Cover it, insulate it, but do not mummify it.

Turning the water back on while everything is still frozen. Repressurizing a line that still has ice in it is how a hairline crack becomes a burst. Wait for a genuine thaw before opening the valve, and open it slowly.

Controllers and rain sensors

Worth checking while you are out there. A rain sensor that has failed will not stop a cycle, and plenty of the ones we find have simply worn out without anybody noticing. If your controller has a seasonal adjust setting, turning it down going into winter reduces how much water is sitting in the lines to begin with.

Smart controllers help here, but only if they are actually connected. We regularly find units that lost their wifi months ago and quietly reverted to a default schedule, which means the freeze protection everyone assumed was handled was not running.

The bigger picture on freezes

Most years, protecting a system is a fifteen-minute job that never gets tested. Occasionally a front comes through hard enough that the difference between a covered backflow and an uncovered one is a few hundred dollars.

The homeowners who come through freezes cleanest are usually the ones who did the boring version: shut it off, cover the brass, and check it after. It is not complicated work. It is just work that has to happen before the cold gets here rather than during it.