The Water Calculator Contra Costa County

In California, more than half of the water used at your home is for outside purposes. Studies show that on average, half of the water used outdoors is wasted. The leading cause of waste is incorrectly set and poorly managed irrigation controllers. The Irrigation Schedule Calculator is intended to give you crucial advice on how to set your controller properly and how to manage it thereafter. Use the button below to begin:


Watering Days per Week: This is the number of days per week that watering will occur. Different planting zones in your landscape will be irrigated on different weekly schedules. This is generally set on controllers as “Program A”, “Program B”, etc. For example, if you have a combination of Lawn zones, General Planting zones and Low Water Plants zones, each of these will be programed on a separate Program on your controller. Lawns on Program A, General Planting zones on Program B, and Low Water Plant zones on Program C.

Minutes per Cycle: This is the number of minutes to set your controller to water for each zone. The Minutes per Cycle X the Cycles per Day will be the total number of minutes watered each day. This Calculator calculates this number to avoid runoff.

Cycles per Day: Most soils cannot absorb water as fast as sprinklers apply it. So we use multiple Cycles per Day to reduce the chance of runoff. So for example instead of watering one time in the morning for 15 minutes, we set the controller to water for 5 minutes, three times in the morning. This will result in reducing runoff and getting more water to the roots of the plants.

Application Rate: The Calculator assumes an application rate for each of the irrigation devices. Application rate is the assumed amount of water being applied in inches per hour. The Calculator uses the following assumptions for Application Rate:

  • Spray Sprinklers: 1.8 inches per hour
  • Single Stream Rotors: 0.9 inches per hour
  • Multiple Steam Rotors: 0.55 inches per hour
  • Drip Emitter: 0.3 inches per hour
  • Microspray: 1.1 inches per hour
  • Inline Drip: 0.3 inches per hour

Recommendations: Program your irrigation controller using this watering schedule as a starting point. Then observe your plants for stress or overwatering, and increase or decrease watering times as needed.

Check your irrigation system several times per year for breaks, leaks, and other problems. This can save your landscape and a tremendous amount of water.

You can track your water use by reading your water meter. CCWD has an easy to follow guide to help you understand how to read your water meter and how to use it as a tool to check for leaks. Visit and search the site for “How to Read your Meter”.

This calculator is intended to help conserve water, please adjust your runtimes so that runoff does not occur.

Disclaimer: The information provided by this calculator is of a general nature and must be interpreted by the user for their own specific needs. Therefore the Contra Costa Water District and GardenSoft cannot be held liable for any landscape losses or damages from the use of this information. The reader of this information is responsible to verify these suggestions with local irrigation professionals.