It is easy to spot an irrigation problem when Mother Nature isn’t providing rainfall. Dry areas become quite visible when temperatures rise and little rainfall occurs. Typically, irrigation problems have a distinct pattern. When these dry spots appear, it is a good time to test your irrigation system to make sure it’s operating correctly. Check the controller, too, because most water management districts allow twice per week irrigation when the clocks change.

Make sure that all the sprinkler heads are working, and unclog or replace heads that are malfunctioning, broken, or missing. Sometimes, heads may need to be redirected. Adjust heads so they’re watering only the landscape—not sidewalks, streets, or driveways.

If you are not sure that the brown area is caused by an irrigation problem, you may also want to calibrate your sprinkler system to determine how much water your system is applying in a given amount of time. Many times, over- or under-watering is occurring in the lawns without knowing it. Calibration is an easy process that can be done by anyone.

• Gather five to ten coffee cans, tuna cans, jars, or other straight-sided containers; these will catch irrigation water. Containers that are 3 to 6 inches in diameter work best.
• Place the containers in one zone at a time, scattering the cans randomly throughout the zone. Repeat this procedure in each zone.
• Turn the water on long enough to get at least 1/4 inch in most of the containers (at least 15 minutes for spray heads and at least 30 for rotors).
• Use a ruler to measure the depth of water in each container. The more precise the measurement, the better your calibration will be. Measurements to the nearest 1/8 of an inch should be adequate.
• Find the average depth of water collected in the containers by adding up the depths and dividing by the number of containers.
• To determine the irrigation rate in inches per hour, divide minutes of run time by 60 to convert minutes to hours and then divide average inches by hours.

Now that you know the sprinkler system irrigation rate, you can apply water to the turf more efficiently. For example, if the sprinkler system applies water at the rate of 2 inches per hour (or a 1/2 inch per 15 minutes) and the grass typically needs about 3/4 inches of water per application, then you would need to run the sprinklers about twenty-three minutes (0.75 inch/2 inch per hour=0.375hr x 60=22.5min).

The UF/IFAS publication on Basic Repairs and Maintenance for Home Landscape Irrigation Systems is available here.

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