How to Winterize Your Sprinkler System in Central Texas

Why Winterizing Matters Even in Mild Central Texas

Water expands about nine percent when it freezes, and that expansion is powerful enough to split brass, crack PVC, and shatter valve bodies. Underground lines are usually safe because soil insulates them and our freezes rarely reach deep, but anything above ground or at the surface is exposed - most critically the backflow preventer, which sits above grade by code and is often the first thing to burst.

Because our freezes are brief and unpredictable, many homeowners skip winterizing and get away with it for years, then lose a backflow assembly and a few valves in one bad cold snap. Replacing a burst backflow preventer and repairing cracked lines in spring costs far more than an hour of prevention in the fall. The goal is not northern-style blowouts - it is protecting the handful of components that a hard Texas freeze actually reaches.

The insidious part is that freeze damage often hides until spring. Water freezes and cracks a fitting in January, but you do not discover it until you turn the system back on in March and a line geysers or the backflow weeps. By then the small crack has become a gushing leak and a surprise water bill. Winterizing is cheap insurance against a problem you will not even see coming until the system is running again.

Step-by-Step: How to Winterize Your System

Work through these steps before the first hard freeze, typically late November to early December in Central Texas. The whole process takes under an hour for most residential systems.

• 1. Shut off the irrigation water supply. Find the main irrigation shutoff valve (often near the meter or where the line branches off the house) and close it so no new water can enter the system.
• 2. Turn off the controller. Set the timer to Rain, Off, or the seasonal mode so it stops running cycles. Your programming is retained; the system simply will not open valves.
• 3. Drain the water from the lines. Open the test cocks or drain valves on the backflow preventer and any manual drain valves to let water out of the above-ground assembly and exposed piping. On systems with drain valves at low points, open those too.
• 4. Insulate the backflow preventer. Wrap the assembly in insulation - foam covers, insulating tape, or an insulated pouch - covering the brass body, valves, and exposed piping while leaving the relief port able to drain. This is the most important single step.
• 5. Protect other exposed components. Insulate any above-ground pipe, and cover exposed valve boxes. On extreme-cold nights, some homeowners add extra towels or a heat source rated for outdoor use around the backflow.
• 6. For extended hard freezes, consider a professional blowout. If a rare multi-day deep freeze is forecast, a compressed-air blowout clears every drop from the lines. This is optional in most Central Texas winters but worth it before an arctic blast.

Protecting the Backflow Preventer: The Weak Point

The backflow preventer deserves its own attention because it is both the most freeze-vulnerable component and a legally required one. It sits above ground so it can be tested, which is exactly what leaves its brass body exposed to freezing air. When water inside freezes and expands, the brass cracks - and a cracked backflow assembly must be replaced, not patched.

Insulate it thoroughly but correctly: cover the body and pipes, but never seal the relief valve port completely, or it cannot function or drain. Insulated backflow covers made for the purpose are inexpensive and reusable. If yours is in an especially exposed spot, drain it fully via the test cocks before wrapping so there is minimal water left inside to freeze.

One more note tied to the backflow: Texas requires annual backflow testing by a licensed tester under TCEQ rules to protect the potable water supply. Fall is a convenient time to bundle that certification with winterizing, so your system is both compliant and freeze-protected heading into winter.

Spring Startup: Bringing the System Back Safely

Winterizing has a matching spring step, and rushing it undoes your careful fall work. When the freeze risk has passed - usually by March in Central Texas - reverse the process slowly. Remove insulation, close any open drain valves and test cocks, and turn the main supply back on gradually rather than all at once, so a sudden surge of pressure does not stress fittings that expanded and contracted all winter.

Then run each zone manually and walk the yard. Watch for heads that cracked over winter, spraying geysers, low pressure that signals a hidden line break, or a weeping backflow that did not survive a freeze. Catching these on a controlled startup - rather than discovering them from a surprise water bill in June - is the payoff for a careful shutdown. Reset your controller to the spring watering schedule and your legal watering days before letting it run automatically again.

It is smart to bundle spring startup with your annual backflow test. Turning the system on, testing every zone, and having the backflow assembly certified in one visit means you enter the growing season knowing the whole system is sound and compliant. If a freeze did crack the backflow over winter, the test catches it immediately, before a failed device can allow any cross-connection with your drinking water - which is the entire reason the test is required.

Let Oakwood Landscaping Winterize and Certify Your System

If your backflow preventer is exposed, your system is complex, or a hard freeze is in the forecast and you want it done right, we handle winterizing, freeze-damage repair, and annual backflow testing across Round Rock, Georgetown, and Cedar Park. We also thaw and repair pipes when a freeze catches a system off guard.

Oakwood Landscaping is a TCEQ Licensed Irrigator, licensed, insured, and BBB accredited, so your winterizing and backflow certification are done to code. Call (323) 606-0255 to schedule a fall service and go into winter protected.