How Much Does Sprinkler Winterization Cost in Flagstaff?

Short answer: a one-time sprinkler winterization with AZ Irrigation & Maintenance is $165 for the first hour, and that includes the service charge. If the job runs past an hour, it's $165 an hour billed by the minute, and any parts are billed separately. AIMazing Irrigation Package members pay $135 for the first hour and $135 an hour after that.

That's the whole price list. No mystery "blowout special" that turns into something else once the truck shows up.

What actually moves your number is your system. More zones take longer to clear. A cracked fitting we find along the way is a part. A backflow assembly with no insulated cover is something we'll talk to you about before we leave.

Winterization pricing at a glance

Parts are billed separately on one-time service. If your backflow needs an insulated cover and you don't have one, we can supply it at an additional cost.

Members pay about 18% less per hour, and the spring turn-on, mid-season check and fall winterization land on the calendar without you having to remember any of them. You can switch back to one-time service anytime. More on that on the AIMazing Irrigation Package page.

Why Flagstaff sprinklers need this every single fall

Flagstaff sits up around 7,000 feet. Nights freeze, days warm up, and then it happens again. Over and over, all winter.

Here's the problem. Turning off the water doesn't empty the pipes. Gravity drains some of it, but water hangs around in low spots, valve bodies, sprinkler heads and the backflow assembly. Most residential lines aren't buried very deep, so that leftover water is sitting right where the cold can reach it. Water expands when it freezes. Your PVC does not.

Skip it and here's the usual spring lineup:

• Frozen pipes and cracked fittings
• Damaged valves and sprinkler heads
• Hidden leaks you don't find until you turn the system back on

One missed blowout can mean cracked pipes and a full system replacement. That's a much bigger invoice than an hour of our time in October.

What actually happens during a blowout

Winterizing isn't just turning the water off. If it were, you wouldn't need us (and we'd have a lot more free time in the fall).

Here's what our Irrigation Association certified technicians do:

1. Shut off the water to the irrigation system.
2. Drain and protect the backflow assembly.
3. Blow out every zone, one at a time, with a commercial compressor. It's high volume, low pressure air, and we keep going until only mist comes out. Too much pressure can damage pipes and heads, so we control it.
4. Shut down the controller and set it to Off or Rain, so it doesn't try to water your lawn in January.
5. Look for visible problems while we're there, so you hear about them now instead of in spring.

If we find something that needs fixing, we sort it into what's critical, what's recommended and what can wait, and we tell you before any work starts.

The backflow: the most expensive thing to freeze

Your backflow preventer keeps landscape water from getting into your home's drinking water. It also sits above ground, holds water, and is one of the most vulnerable parts of the whole system once temperatures drop.

So it needs to be insulated. You've got two options:

• Buy an insulated cover from us (additional cost), or one you already own.
• Follow our backflow protection video guide and prep it yourself before we arrive.

Either way, we'll check your backflow setup during the winterization and make sure it's protected. If you'd also like it tested, that's a separate service. See backflow testing.

Your stop-and-waste valve: check it this winter

The stop-and-waste is the valve that shuts water off to your irrigation system. Even after a blowout, we recommend checking it now and then over the winter. These valves typically last 10 to 20 years, and old ones can fail.

The sneaky failure is a slow internal leak. Water creeps past the closed valve and quietly refills the lines you just paid to empty. One sign: water dripping from the backflow test port when the system is off and winterized. We'll show you how to check yours. More detail in Why is my stop and waste valve leaking?

When to book

Before the first hard freeze. Earlier is better. Our winterization page has a neighborhood schedule map. Zoom in, tap your neighborhood, and you'll see the approximate service date for your area.

If it's late October and your system is still full of water, don't wait for a nicer week. Call us.

AIMazing members skip this step entirely. We schedule winterization around actual Northern Arizona weather, send a heads up by text and email, and leave a door tag when we're done.

Just bought a house with a sprinkler system?

Congratulations. You also inherited somebody else's irrigation decisions.

New homeowners often don't know where the stop-and-waste is, whether the backflow has a cover, or how many zones they own. That's fine. Book a winterization and ask questions. We'll walk you through the valve and the backflow while we're there. One of our customers, Geri Beaty, called us after a surprise water bill at a new home:

"Was referred to AZ Irrigation & Maintenance by neighbor who had a great experience. After a $1k water bill in Jan at our new home knew it was time to call. Ken spent 7 hrs at our 1 acre property that the previous owner had completely neglected. Found multiple leaks & repaired. Tested out 15 zones from three boxes and completed the gallons per minute test & send me the results via text. After he left we noticed the water meter still running....he returned same night & assisted with sleuthing out where the problem was coming from. Turned out it was not even the irrigation and he STILL assisted my husband with the fix. You don't find service and smarts like Ken very often any longer! He's certified & trained in multiple areas. We love our landscape team, but they aren't irrigation experts. This was a great compliment to them. We will be joining their annual contract for spring & winter inspection and turn on/off for the seasons! Call them:)"
Geri Beaty, Google review, May 2026

And the short version, from a customer who already has it on autopilot:

"I have AIM turn my irrigation system off for the winter and on for the summer. Louis did a great job turning my system on and I could tell he checked out all the emitters to make sure they were working properly."
James Hoyne, Google review, April 2026

Where we winterize

We winterize sprinkler and drip systems in Flagstaff, Doney Park, Kachina Village, Munds Park, Bellemont and Williams, plus Sedona and the Verde Valley.

Book your winterization

Call 928-225-2224 (answered 24/7) or get a quote online. Want the full service details first? Here's our sprinkler winterization and blowout page.

And when spring comes around, we'll be there for the spring turn-on too. If something broke over the winter anyway, here's sprinkler repair.