As we move out of winter weather and approach the summer months, now is a great time to give your lawn’s irrigation system an audit.
Just like a financial audit makes sure that funds are where they ought to be, an irrigation audit confirms that your sprinkler system is putting water where you want it and at the correct amount. Irrigation audits are a great way to make sure your system is operating efficiently so you can conserve water in your landscape. It is also a great DIY project for you to do on your own.
You’ll first look to make sure all sprinkler heads pop up when their zone is running. Next, look for broken or leaning sprinkler heads. Turn on each zone and watch carefully to confirm that nothing is broken, that the spray pattern is going where you want it to go, and that you are not spraying water into the street, your driveway or other hardscaped areas of your yard. Occasionally, you may need to trim back shrubs so that a proper spray pattern is kept.
Identify any sprinkler heads that need adjusting or replacing. You can find replacement heads at larger gardening centers. Many times, it is as simple as removing the old sprinkler head and screwing in a new one. Run that zone again to confirm it is in proper working order.
Performance testing is a way to check how much water your irrigation system is putting out in your lawn. The best way to check this is by setting out some small rain gauges. I have heard that others often use tuna cans or small plastic food storage containers.
Put the cans out in several spots throughout the lawn, run your irrigation system for ten minutes, then measure how much water was fallen in each can. This helps you know the average amount of water your system puts out in ten minutes, and you can adjust your schedule to get the appropriate amount of water on your lawn each time you water.
Irrigation scheduling is the final, and possibly most important step in an irrigation audit. There are a lot of factors that go into the formula for figuring out how much water a lawn needs. Factors that alter settings over the year include temperature, relative humidity, plant requirements, soil type, and more. The rule of thumb for turfgrass is one-inch per week in the summer and less in the spring and fall. You can divide your watering schedule into two times per week at half an inch per irrigation time.
Remember to water only if your lawn needs to be watered. Look for visible wilt in your turfgrass. Never irrigate after a good rain. Water only after the top two inches of the soil has dried out. You can use a soil probe to determine soil wetness or simply use a long screwdriver. If the screwdriver is easily pushed into the ground, you know you have plenty of moisture in the root zone.
An easy rule of thumb is to provide one inch of water or more every five to seven days to promote deep roots. Grasses and shrubs will become more drought resistant if you give them infrequent and deep irrigation.
When done correctly, you will adjust the run time and frequency on the automatic controller each month, based on changing rainfall and temperatures.