If you have an irrigation system in Spokane, this is the one piece of yard maintenance you genuinely cannot skip. Here is when to do it, why the timing matters more here than in milder climates, and what it costs if you get it wrong.
The short answer
Schedule your sprinkler blowout between late September and mid-October. Spokane typically sees its first hard freeze in early to mid-October, and you want the water out of your lines before that happens — not the week it is forecast.
If you want a single date to aim for: the first week of October. That gives you a buffer if the weather turns early, and it puts you ahead of the rush.
Why the timing is tighter than people think
The mistake is treating the first freeze as a deadline. It is not a deadline, it is the point at which damage has already happened.
A light frost will not hurt your system. What does the damage is a sustained freeze that reaches the water sitting inside your backflow preventer and lateral lines. In Spokane that can arrive in the first week of October some years and hold off until November in others. You do not get advance notice, and by the time the forecast shows it, every irrigation crew in the county is booked.
That is the practical argument for going early. Not because your pipes will freeze in September, but because the last two weeks before a freeze are the two weeks nobody can get to you.
Why draining it yourself usually is not enough here
This is the most common thing we hear: “I just open the drain valves and let it run out.”
In a perfectly level yard with perfectly sloped lines, that works. Almost no yard in Spokane or Spokane Valley is perfectly level. Lines follow the ground, the ground has dips, and water settles into every low spot that gravity cannot reach.
Water expands roughly 9% when it freezes. That expansion inside a sealed brass backflow assembly is what cracks it — and a cracked backflow housing cannot be repaired, only replaced. Compressed air is the only method that reliably clears the low spots gravity leaves behind.
What it costs if you skip it
This is the part worth being blunt about, because the numbers are not close.
- Sprinkler blowout: $85 for up to 5 zones
- Backflow preventer replacement: $450 to $1,700
- Broken or split line: $125 to $400 per break
And freeze damage rarely stops at one break. You typically find out in April, when you turn the system on and water comes up through the lawn somewhere it should not.
Eighty-five dollars in October against several hundred to a couple thousand in spring. That is the entire decision, and it is not a difficult one.
What actually happens during a blowout
It is a short visit — 20 to 45 minutes for most residential systems, depending on how many zones you have.
- We connect a compressor at the backflow and push air through each zone until the heads run clear
- The main irrigation supply gets shut off and drained
- The backflow preventer is drained and protected
- Your controller is set to off or rain mode for the season
- If we spot anything that needs attention before spring, you hear about it
You do not need to be home, as long as we can reach the backflow and the controller.
Should you do it yourself?
You can, if you own or rent a compressor with enough volume. The important number is not pressure, it is CFM — a small pancake compressor builds pressure but cannot move enough air to actually clear a zone, which is where most DIY attempts fall short.
There is also a real risk of over-pressurising. Too much PSI will damage seals, heads, and the backflow itself, which puts you right back in the expensive column.
For most homeowners, an $85 visit once a year is not worth the rental fee and the risk. But if you have the right equipment and know your system, there is nothing mysterious about the process.
How many zones do I have?
Check your controller — it lists them as zones or stations. Most homes in Spokane and Spokane Valley run three to five, which is covered by the $85 flat rate. Above five zones it is $10 per additional zone.
If you are not sure, do not worry about it. Leave it blank when you book and we will sort it out on site.
Book before the rush
We run blowouts across Spokane and Spokane Valley from late September through October, including the South Hill and Liberty Lake. Booking takes about a minute — tell us your address and roughly which week suits you, and we will confirm your day.
See full pricing and book your sprinkler blowout here.
Ready to get on the fall schedule?
$85 for up to 5 zones in Spokane and Spokane Valley. Book online in about a minute.
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