Watering Calculator

It’s a fact that up to 70 percent of residential water use is for landscape. One of the most effective ways to conserve water is to irrigate efficiently. The Watering Calculator tool estimates the correct amount of water to give your landscape or garden every week during normal weather conditions. Developed by the city of San Diego, it provides customized watering schedules by zip code based on data from the California Irrigation Management Information System weather station network.

How to use the Watering Calculator:

Name this landscape area? (e.g. front yard)

What type of watering system do you have?


*If you are using a Sprinkler, Rotor, or Micro-Spray, and you know your application rate, please enter it here:

IMPORTANT: The Watering Calculator is not adjusted for drought conditions or watering restrictions and should only be used as a guide. Communities may have mandatory watering restrictions that limit the days, times and duration that customers can water their landscapes. These regulations vary across Southern California. In situations where the calculator indicates that less water is needed on a weekly basis, customers should adjust usage to meet the plants’ needs and allow deep rooting but not exceed the maximum allowed minutes per day. Check with your local water provider to find out the watering days and times allowed in your area.