Automatic sprinkler systems are convenient, but they can easily waste 30% of the water used for irrigation, per the Irrigation Association. Setting a base schedule, adjusting the amount you water seasonally, and keeping up with your annual maintenance are the best ways ensure that your system is working effectively and efficiently. 

 

Set A Base Schedule

The first step to fine tune your sprinkler system schedule is to figure out how long it takes your sprinklers to water one inch.

Next, set your sprinkler to water a one-inch base schedule. This is the amount it needs in the hottest, driest part of summer (100% of its maximum water need).  This feature should be programmed into most automatic sprinkler systems.

1. Determine if it is equipped with a "water budget" or “percent adjust” feature (this is often on a dial or a button in the controller box). 
2. Set the "water budget" or “percent adjust” to 100%.

Once you set your controller’s base schedule, you will be able to adjust it to reflect your landscape’s needs and local weather conditions by using the Weekly Watering Number.

 

Use clues from your landscape to fine-tune your base watering schedule

Each landscape is unique. So are its irrigation needs. The actual water requirements for any part of your landscape should take into account the amount of sun or shade an area receives, the slope of the site, the soil conditions, and the type of plants being watered. All of these factors will affect your base watering schedule.

 

Regularly Adjust Your Watering Schedule

The key to efficient irrigation is to adjust watering schedules frequently during the season. If you set your automatic controller once and let it run all season, you’re very likely wasting a lot of water.

Most modern controllers allow you to easily set a base schedule which can be adjusted weekly or seasonally. 

 

How to change your sprinklers' watering schedule weekly or seasonally with your local weather conditions:

1. Set each watering zone’s base schedule with the “percent adjust” or “water budget” feature set at 100%.
2. Adjust the "water budget" or “percent adjust” feature for each watering zone to the percentage that corresponds with the Weekly Watering Number.

Note: some controllers will allow you to adjust to the nearest 1% while others only allow you to adjust in increments of 10%, so you may have to round up or down (for example: 130% instead of 127%).