Does my sprinkler system need backflow testing in Portland?
Almost certainly yes. An in-ground sprinkler or irrigation system is the single most common reason a Portland-area home has a backflow prevention assembly — and every backflow assembly must be tested once a year under Oregon law (OAR 333-061).
Why sprinklers specifically
Irrigation lines live in the dirt. They're in contact with soil bacteria, fertilizer, pesticides, and standing water. If pressure in the public water system ever drops — a main break, a big fire-hydrant draw — water can get siphoned backward from your yard into the drinking water supply. The backflow assembly is the mechanical one-way barrier that stops that, and the annual test is how anyone knows it still works.
How to tell if you have one
- Look where the irrigation line branches off your main supply — near the meter, along a side yard, or in a rectangular valve box set into the ground.
- If your system was installed with a permit, it has an assembly — installation without one isn't allowed.
- If you got a notice letter, the city already has your assembly on record.
Still can't find it? See our guide to locating your assembly.
"But I never use my sprinklers"
Doesn't matter — a dormant system still needs its assembly tested as long as it's connected to the water supply. Here's why, and what your options are.