Choosing an Irrigation Control System

~ Manual systems keep you in touch with your garden and its water needs. You must decide each day if, when and how much to water. You must be there when its time to turn the system on and when its time to turn it off. Studies show that people with manual systems use less water than people with automatic systems. Setting a timer will help to remind you when to shut the valve off.

~ Semi-Automatic systems, which work similar to a kitchen timer, require you to turn the water on manually but the system turns itself off at the end of the time (or number of gallons) you set.

~ Automatic systems are the most common type. They use an electronic or battery operated controller to do all the work for you. Traditional automatic systems never forget to water . . . even if its raining. Because we can ignore automatic systems, studies show that people with these systems use more water than people with manual systems. : If the irrigation controller has a battery, it should be changed every 12-18 months (like your smoke alarms). The battery will maintain the program(s) you have set in the event of a power failure. If the battery cant hold a charge, when power is restored the program(s) will be lost and the controller will revert to whatever settings were programmed by the manufacturer. If the battery isnt visible upon opening the box, you may have to remove the cover plate to locate it. WATER SAVING TIP: Consider turning your controller to the “Off” position during the cool season (e.g. November March) or during rainy periods. Run manually a couple of times a month if needed. DO NOT unplug the controller because the program will be lost.

~ Smart systems, which are now affordable for residential use, add sensors and/or telemetry to the controller to adjust automatically for the day-to-day weather changes in your garden. Studies show that Smart controllers save a lot of water.

How Much / How Often - Check for City of Fresno water restrictions.  Please refer to the Watering Guide on the Main Menu. You have choices to make about your watering schedule:

1. What time of day to water [If you have an automatic controller, this is usually called Start Time or Cycle Start]

In general, to reduce water loss by evaporation, it is best to water during the early morning hours if you are using a spray system. For drip systems, you may choose any time you like within the Citys watering schedule. Sometimes, when using watering devices, like sprayheads or bubblers, which apply water faster than the soil can accept it, you may need several start times spaced out over a longer period. See "5. Too much water too fast" in Irrigation, Maintenance and Troubleshooting. Watering between 6:00 am and 7:00 pm is currently prohibited in the City of Fresno.

2. How long to water [Run Time or Water Time] Refer to Watering Guide on the Main Menu.


Smart , WBIC or ET Controller

What is a “smart” irrigation controller?

“Irrigation controller” is a term that landscape professionals often use when referring to the device (typically a “timer”) that controls your homes outdoor sprinkler system. However, unlike timers, which water on a set schedule, “smart” irrigation controllers use regional weather, site, or soil moisture data as a basis for determining an appropriate watering schedule.

Also known as "WBIC" or "weather-based,"  "ET" or "Evapotranspiration-based,” or “soil moisture sensor-based” controllers, “smart” irrigation controllers have an extensive history of scientific and field documentation. Golf courses, parks, and athletic departments have used climate-based irrigation systems for more than 20 years. This scheduling technology is available for smaller landscapes through “smart” controllers.

How do smart irrigation controllers work?

Traditional irrigation system controllers are really just timers. They turn the water on and off based on a pre-programmed schedule, regardless of the actual weather and soil conditions. Smart irrigation controllers, on the other hand, monitor and use information about environmental conditions for a specific location and landscape, such as soil moisture, rain, wind, evaporation rates, plant transpiration rates, and more, to determine when to water in order to provide the right amount of water to maintain healthy growing conditions.

Because “smart” irrigation controllers are more efficient than traditional, timer-based controllers, they maximize water use efficiency, often reducing usage by 15 percent or more, which saves you money and makes large, positive impacts on your communitys efforts to assure the local water supply.

Smart Controllers self adjust watering schedules according to wind, rain, solar radiation, and humidity. They have the capacity to operate multiple programs and to irrigate during desired times and/or dates.  Smart controllers use one of the following technologies to self adjust watering schedules:  1) onsite weather sensors; 2) satellite reads from local weather stations; 3) historical weather data pre-programmed into the controller; 4) soil moisture levels.

These controllers can reduce run-off, lower your water bills, and make your plant material more resilient, if you have an efficient irrigation design and adequate hydrozones. Smart controllers are not a hands off solution; it is advised that you monitor your plants health. For more information on smart controllers visit the Irrigation Associations Web Site at: .

How does a smart controller make watering my landscape easier and more convenient?

Traditional sprinkler timers require manual adjustments every time the weather changes. “Smart” controllers automatically adjust the watering schedule based on local weather/site conditions. Once the initial setup and monitoring is complete, theres no need to reset the timer unless your plants show stress.

How will installing a smart controller save me money?

A smart controller saves you money by reducing your water use. Your actual water savings will depend on how you have watered in the past. Pilot studies have shown typical water savings to be in the range of 15 - 20 percent annually. Smart controllers also save money by providing a healthier landscape, since a landscape which is properly watered will be less likely to suffer from fungal disease and insect infestations that can require costly treatments, thereby protecting your landscape investment. Always keep in mind that a smart controller can save money only if the irrigation is property maintained and in good repair.

Can I install a smart controller myself?

The proper installation and initial setup of smart irrigation controllers generally require an in-depth knowledge of soils, precipitation rates, slope measurements, and related factors. Therefore, we strongly recommend you work with a certified irrigation contractor who is experienced in the installation of smart controllers.

What questions should I ask before purchasing a smart controller?

The Irrigation Association, a non-profit organization supporting water conservation through efficient irrigation, has published an Irrigation Consumer Bill of Rights to educate consumers about the questions to ask their contractor before purchasing a new irrigation system. Be sure to read it prior to meeting with your landscape professional and before beginning any work, and confirm that your contractor is specifically trained in the installation of the smart controller selected.

Where do the automatic adjustments come from?

Smart controllers receive the environmental data they need from various sources, depending on the make and model. Some models use data from local weather stations or on-site sensors, while other models gather information from several weather stations linked to match the zip code and address of the installation site. Each type has the capability to work equally well. Look for the type suited to the unique attributes of your home landscape.

How much do smart controllers cost?

The cost of smart controllers varies according to the number of zones and features included in the controller model you select. Most range in price from a few hundred dollars on up, plus installation. In addition, some weather station-adjusted controllers require a monthly or annual fee for transmission of daily weather information. Other, internal sensor-based smart controllers rarely require transmission fees.  

Which smart controller works best?

Different smart controllers each have different features and benefits. A certified landscape/irrigation contractor can help you make the best choice for your specific needs.

How have these products been tested?
Manufacturers of smart controllers rigorously test their products before releasing them for sale. In addition, the Irrigation Association has recently developed an independent third party testing protocol specific to smart controllers. The results of these tests are available at Locally, the Center for Irrigation Technology (CIT) at CSU Fresno has tested many components of irrigation systems and the data is available on their website:

On the website there is information on the software SPACE Pro that allows you to test different systems and a note that SPACE Online is coming soon which will allow access to all of CIT’s data from any computer in the world. More information about CIT’s programs and events is available at:

If I install a smart controller, will I get a discount on my water bill?
Less water used for sprinkling means less water delivered through your water meter. When you reduce water use by installing a smart controller, your reduced use will result in a reduced water bill. Be aware that “smart controllers” may not comply with a municipalitys watering schedule.