Irrigation Blowout & Winterization in Kelowna & the Central Okanagan

An irrigation blowout is the process of forcing compressed air through an irrigation system to push out every bit of water left in the pipes, valves and sprinkler heads before winter. A contractor shuts off and isolates the water supply, connects a compressor at the blowout port, then opens each zone in turn until only air and mist come out of the heads. It is done because water expands as it freezes, and buried pipe is the most expensive possible place to discover that.

We do not publish prices, because the work is quoted by independent contractors and the number depends on the property. The things that move it most are the number of zones, the length of mainline, whether there is a pump, filtration or an above-ground backflow assembly to drain, how accessible the blowout port and valve boxes are, and how late in the season you book. Requesting two or three quotes is the reliable way to find out what your system should cost, which is what this service is for.

Before the first hard frost, which in the Central Okanagan valley usually means sometime in October — earlier at elevation. Because being early has no downside once you have stopped watering and being late risks cracked pipe, the sensible approach is to book toward the early end of the window rather than waiting for cold weather to force the decision.

Draining alone is not sufficient on most systems. Even with drain valves and favourable grade, laterals and low points retain water that gravity will not remove, and it only takes a small amount in the wrong place to crack a fitting or a valve body. Compressed air is used because it clears water that draining leaves behind.

The main risk is pressure, and it is a real one. Too much air pressure damages heads, seals and fittings, and it is easy to exceed safe limits with a compressor sized for tools rather than irrigation. Volume matters more than pressure for clearing lines. If you do it yourself, work zone by zone at low pressure and never leave a zone running dry on air longer than needed.

Sometimes nothing, in a mild winter. More often it means cracked laterals, split valve bodies or a damaged backflow assembly, and because the damage is buried you typically discover it at spring start-up when the system will not hold pressure. Repair costs then run well beyond what the blowout would have been.