<font color=blue>INDUSTRY BUZZ</font> The Order of Irrigation

The construction site is usually a hectic place, especially by the time the irrigation crew arrives. Because of the logical order of things, the irrigation installation should follow a certain sequence in order to insure the quality of the installation. Of course, the order of activities can be changed somewhat, but not without an impact. 

Water Source
Prior to delivery of materials and crew arrival, the irrigation contractor should have checked on a few things. First, make sure the identified water source is adequate in both pressure and flow to supply the irrigation system sufficiently. Second, identify the irrigation contractor’s point of connection and verify that any needed plumbing, backflow, metering and/or pump work has been performed as required.  Having water available to use for flushing and testing will not only speed the overall job time up, it will make for a better finished product as water is necessary to flush any debris from pipes and fittings prior to valve and sprinkler installation.  Contamination is the leading cause of product failure on new installations. Dirt, rocks and other contaminants foul sealing surfaces and jam moving parts causing failure or at least extra time to clear the debris. 

Main Line and Control System
Installation of main line piping, control wire, controller and control valves is the next logical step. Prior to installing any control valves, it is important to flush debris from the pipe network. Make all pipe and wire connections using methods and materials specified by the manufacturers involved. 

Lateral Pipe and Sprinklers
Many times, this activity tends to overlap with main line installation. For the sake of maximizing machine productivity, this makes sense. Just be sure to flush debris from lateral piping before installing any sprinklers. Once again, comply with all manufacturers recommendations when making these connections and be sure to take precautions to prevent further contamination.

Test and Adjust
Activate each individual zone and adjust the sprinklers to deliver water as intended. Take steps to prevent overspray onto hard surfaces and buildings.  Cycle the control valves on and off several times with the controller to be sure they are functioning properly.

Programming and Owner Instruction
Finally, program the system to deliver only the amount needed for plant vigor and health. Hopefully, the design has incorporated equipment that will self adjust with changing climate and suspend cycles in periods of sufficient rainfall. It is important to communicate to the owner any need for ongoing adjustments and assign responsibility for doing so if necessary. Also, providing the owner with documentation for each of the components as well as tools to make minor adjustments can save callbacks.

Summing it Up
On occasion, the calendar and clock put tremendous pressure on an irrigation contractor to re-sequence the natural order of the installation. The irrigation crew may have to “jump ahead” and install some lateral pipe and sprinklers in a plant bed so the landscape crew can finish off a certain area. Or maybe the plumber won’t have his work completed until a later date. Whatever the case, whenever this happens, there are almost always problems related to contamination of the irrigation system. Contamination of piping and components is the leading reason for costly return visits. In summary, one can easily see the importance of having water available for use throughout the installation. Water has to flow from the source to the sprinkler; the job should do that as well. 

The author is the IA’s State and Affiliate Relations Director. For more information, e-mail andy@irrigation.org.