The annual process of commissioning an irrigation system marks its transition from winter dormancy back to active service. This systematic procedure prevents costly damage to pipes and components that may have occurred due to freezing temperatures. A methodical approach ensures the system operates at peak efficiency, delivering water precisely where and when it is needed. Properly recommissioning the system minimizes the risk of leaks and ensures water is not wasted.
Pre-Water System Checklist
Begin the process by locating and securing all drain valves and winterization ports used during the shutdown process. These ports, often found at the low points of the system, must be fully closed to prevent immediate water loss upon pressurization. Ensuring all openings are sealed maintains the hydraulic integrity of the main lines before the water supply is engaged.
Attention must turn to the backflow prevention device (BPD), which protects the potable water supply from contamination. Check the position of the test cocks and shut-off handles on the BPD. On many residential systems, the handles should be positioned at a 45-degree angle during the initial setup to facilitate a slow introduction of water. Local regulations often require a certified technician to inspect and test this assembly annually for compliance.
Perform a thorough visual inspection of all exposed components, including sprinkler heads and risers, looking for obvious signs of physical damage. Check for cracked casings or tilted heads that could lead to significant leaks, as components can be misaligned or broken by snowplows or shifting soil. If the system utilizes a pump from a well or pond, confirm the pump is properly primed before allowing water to flow into the mainline.
Controlled Water Pressurization
The introduction of water to the system requires extreme caution and patience, making this perhaps the most time-sensitive step for preventing damage. First, identify the main water supply valve, typically situated near the water meter or where the line enters the property. With this valve located, begin to open it using very small increments, initiating the flow into the empty main lines.
The valve should only be opened by a quarter turn, followed by a waiting period of several minutes. This deliberate slowness is necessary to gradually displace trapped air within the pipes, allowing it to escape through the sprinkler heads or other system openings. Repeating this sequence prevents a sudden surge of pressure that can damage the system’s components.
Rapidly opening the main valve can trigger water hammer, a pressure spike caused by the sudden deceleration of water and air. This intense kinetic energy shockwave can stress and rupture pipe joints, heads, and even the backflow device, which is why the slow pressurization method is recommended. During this phase, listen intently for any unusual hissing or rushing sounds, which indicate a significant leak in a buried line.
Zone Testing and Controller Setup
Once the main line is fully pressurized without incident, the focus shifts to verifying the operational status of individual zones. Use the irrigation controller to manually cycle through each zone sequentially, observing the performance of the sprinkler heads. Look specifically for “geysers” or large puddles near the heads, which indicate a severe break or a head that has completely separated from the riser.
As each zone runs, examine the spray pattern and coverage to ensure water reaches the intended landscape areas and is not spraying pavement or structures. Adjusting the arc and distance of the heads is often necessary after winter, typically requiring a specialized adjustment key or a small flathead screwdriver. Check that the heads are sitting level with the ground and that pop-up heads extend fully to achieve their designed trajectory.
After confirming the physical components are working, attention moves to programming the controller, which functions as the system’s brain. Begin by setting the current date and time, as modern controllers use this information for features like rain delay or seasonal adjustments. If the controller uses a backup battery to retain settings during a power outage, replace it now to ensure the schedule remains intact.
The final step involves setting the watering schedule, including start times and the run duration for each zone. Starting with shorter run times in the cooler spring months is recommended, as the landscape’s water demand is lower than during the heat of summer. This initial programming should be viewed as a baseline that will require future adjustments to maximize water efficiency.