As long as the irrigation system is connected to your plumbing system, the potential for backflow exists, and you must comply with all backflow requirements, including having it tested each year.
To eliminate these backflow requirements, the irrigation system must be physically disconnected and removed from your plumbing system. Contact a certified backflow tester to schedule the removal and notification to the Cross-Connection Coordinator 360-857-5010. Public Works will schedule an inspection to confirm the backflow assembly has been removed and capped off.