Importance of proper scheduling
Over or under watering can be potentially devastating to your lawn/landscape. Watering too much drowns turf and plants, and under watering leads to wilting and even death of your turf or plant space. Understanding just how much water you’re applying can help make your landscape look beautiful AND avoid ruining any financial investment you’ve put into your lawn.
Finding out how much water each zone is putting out per minute (GPM or Gallons Per Minute)
Each “zone” has a certain number of heads on it because the water pressure can only sustain a certain amount of heads at one time. What you want to do is find out how many heads you have in each zone and also determine if they’re “spray” heads or “rotors”. Most turf areas have rotors and most flower beds have sprays.
Once you have that info, determine how many TOTAL GPM (Gallons per Minute) each zone is outputting based on the types of heads.
Rotors are usually 1.5-3GPM and Sprays are usually .5-1.5 GPM (Start with 2.0 for rotors and .50 for spray heads, unless you know the exact nozzle type in each head)
Determine coverage area for each zone (Area)
This is simply measuring the total coverage area for each individual zone
Find the Precipitation Rate (PR) for each zone
Now that you have the TOTAL GPM and AREA, we’ll use the following formula to determine the Precipitation Rate for each zone
PR (in/hr) = 96.3 x gpm
Determining how many minutes to run each zone per week
On average, you’re looking for about an inch of water per week, per zone. The precipitation rate tells you how many inches per hour each zone outputs, so just break that up into 2-3 days per week, remembering to total about 1″ per week per zone.
This will give you a base starting point for all of your zones. Typically you’ll want to water early morning and just a couple times per week per zone. Deep soaking waterings are better for soil/plant conditions than short waterings everyday. If you water too little too often, you’ll get shallow root bases which won’t develop over time.
Monitor the new settings and make slight adjustments depending on results
You’ll need to make slight changes to get it right for your exact situation, but this is a great start for managing an effective irrigation watering schedule.
For more information, or to see how the pro’s schedule irrigation systems, go here: