In desert climates every drop counts. One of the easiest ways to prevent unnecessary water loss is to winterize your irrigation system before the ground freezes. When sprinkler pipes freeze and crack, they often leak silently under the soil and then gush once the system is turned back on in spring. Blowing out your water lines removes standing water, prevents pipe breaks, and reduces the chance of a seasonal leak that wastes hundreds (or thousands) of gallons. Below is a friendly why-it-matters explanation and a clear step-by-step guide you can follow.

Why blowing out irrigation lines helps conserve water

• Prevents breaks: Water expands when it freezes. Left in pipes, it can cause joints or PVC to crack. A single cracked lateral line can waste large volumes of water before it’s noticed.

• Avoids hidden leaks: Underground leaks often go undetected until meters spike or plants unexpectedly drown. Preventing damage avoids these silent losses.

• Saves money and resources: Fixing broken pipes and repairing landscaping costs time, water, and money. A seasonal blowout is inexpensive by comparison.

• Extends equipment life: Drains valves, controllers, and backflow devices last longer when they aren’t repeatedly stressed by freezing and thawing.

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How to blow out irrigation lines — step-by-step (for typical residential systems)

Important safety notes before you start

• If you’re not comfortable working with compressed air or irrigation hardware, hire a licensed irrigation professional.

• Use eye protection and keep bystanders, pets, and children away from the work area.

• Always use a pressure regulator on the air compressor and never exceed the pressure rating of your irrigation system (a safe typical maximum is 50 psi unless your system documentation allows higher). Check manufacturer guidance if available.

• Use a moisture trap and inline regulator between the compressor and system to protect valves and piping.

  
  

Tools & materials

• Air compressor (capable of steady low-pressure output with regulator) — many rental centers have units marketed for irrigation blowouts

• Quick-connect fittings or blow-out adapter for your irrigation system

• Pressure regulator and moisture trap (oil/water separator)

• Safety goggles and gloves

• Optional: irrigation system manual or map of zones

  
  

Procedure

1. Shut off the water supply to the irrigation system. Locate the irrigation main shutoff (often near the shutoff for municipal water or a master valve) and close it.

2. Release house-side pressure. Open a manual valve at the highest point of the irrigation system or a hose bib downstream to relieve any remaining pressure.

3. Attach the compressor adapter. Connect your blow-out adapter to the system’s blow-out port or to the quick-connect coupling at the backflow assembly. Install the moisture trap and pressure regulator between the compressor and the system.

4. Set the pressure regulator. Start with the regulator at a low setting. Slowly increase to a safe working pressure — typically 30–50 psi for most residential PVC systems. Never exceed the system’s rated pressure.

5. Blow out one zone at a time.

   • Turn the irrigation controller to manual and run the first zone for 2–3 minutes. Watch the sprinkler heads: when only air (no steady water) is coming out and the spray has diminished to a mist, the zone is clear.

   • Turn the zone off, then move to the next zone. Repeat until every zone has had water removed. Short bursts are preferable to long continuous high pressure.

6. Clear the mainline and valves. After zones are cleared, run a short cycle with the main valve (if present) to clear remaining water from the mainline, then stop.

7. Drain low points and above-ground components. Open any manual drain valves, remove drain plugs, and leave valve boxes or backflow devices slightly open so residual water can escape and evaporate. Insulate or enclose above-ground backflow preventers if required by local code.

8. Disconnect equipment and store. Turn off the compressor and disconnect the fittings. Replace caps and covers on valves and controllers.

9. Record the date and note any issues. If you saw pooling water, stuck valves, or damaged heads, plan repairs before the next irrigation season.

   
   

Final tips

• Do this before the ground routinely drops to freezing temperatures in your area—often late fall. Plan in advance; when freezing weather arrives, schedule availability gets tight.

• If your system uses drip lines or micro-sprays, follow manufacturer instructions—drip systems are often drained differently.

• Keep a simple irrigation map and the system manual near your controller for fast reference.

• If you find a leak or a broken pipe, repair it promptly—waiting wastes water and can damage landscaping.

Winterizing by blowing out your irrigation lines is a small seasonal chore that protects your irrigation investment and helps conserve precious desert water. A 30–60 minute DIY session (or a short professional visit) can prevent months of waste and costly repairs—good for your wallet, your plants, and your community’s water supply.