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 Water 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:
* If your irrigation controller has a "Seasonal or Budget Adjust % Feature" we suggest that you program your controller to the July recommendations and then adjust as suggested below:
Seasonal / Budget Adjust % Feature is used to make global run time changes without reprogramming the entire controller. This feature is perfect for making small changes that are necessary as the weather changes throughout the year. For instance, during hotter times of the year, the landscape may require a bit more water. Seasonal Adjust can be increased so the stations run longer than the programmed time. Conversely, as fall approaches the Seasonal Adjust can be reduced to allow for short watering durations.
Minutes per Cycle: How many minutes in a row that station or valve must run at one time. It is the length of one 'run time'. If the minutes per cycle produces run-off, reduce the time and add cycles.
Cycles per Day: This is how many times the above activity must happen to get the plant or turf enough water without incurring runoff. A Cycle is how many times the station or valve runs on a given day. Sometimes known as a run time. Some controllers don't offer as many cycle starts as are recommended in the Calculator. Do the best the controller allows.
Days between Watering: This is how many days must elapse before you should run through the routine of cycle(s) recommended above. Some controllers don't allow more than 7 days per run time or cycle start. Some controllers are based on days of the week and cannot have more than 7 days between watering. Do the best you can with this limitation.
Est. Gallons Used: This is an estimate of the number of gallons of water used for the given month. The estimate is a high and low range, as the exact number of gallons used depends upon some factors beyond the scope of this calculator.
Adjust your automatic timer, as best you can, according to the numbers you get from the calculator. You may need to make compromises based on the limitations of the controller. Pay attention to your plants for stress, and increase or decrease watering times accordingly. Skip two watering days when it rains or when the soil is already wet. Re-program your timer each month using your GardenSoft Water Calculator schedule as a guide.
Important Information: During winter (w) months of November - March irrigation is usually not needed. However, during prolonged periods of no rain occasional irrigation may be needed.
Please note, this Water Calculator uses historical data to generate a general irrigation schedule. To obtain an irrigation schedule that is adjusted weekly based on current weather conditions, please see MMWD's Weekly Watering Schedule.
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 Water Agency 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.