Control the controller

NEWSFLASH: Your biggest untapped water saver may be to control the irrigation controller. Do not shy away from this device as too complex or for specialists. Unlike IBM Watson that “destroys humans in Jeopardy” or Google DeepMind that won 9 of 10 games with top Go players, we humans can win this one.

The key is to carry out needs rather than time-based irrigation. Master that and you’ll find consumption plummets and plants grow strong. My 1-acre garden used 55% less water and began to thrive due to my newfound ability to tailor intake and redesign irrigation and maintenance accordingly.

Controllers offer a range of features, and some have options like rain gauges, weather data, or soil moisture sensors. Outcomes of programming techniques that turn sprinklers on and off vary greatly:

Automatic days to water Low High Low
Automatic days between watering Low Medium Medium
Automatic seasonal adjustment Low Medium Medium
Semi-automatic of zones stacked in program
Medium Low High
Full manual High Low High

Irrigation on fixed days of the week is typical and what we did before rationing. A calendar made for people, though, is a poor proxy for plant thirst and tends to overwater. So I manually activated each zone as needed week-in, week-out for a year. I then created programs of stacked zones to manually activate as needed. This semi-automation was a winner, as good as full manual with far less effort.

The EPA reports that 120 billion gallons of water and $435 million in water costs can be saved each year if U.S. homes with automatic irrigation had properly installed and operated Water Sense labeled controllers, with nearly 8,800 gallons saved yearly by an average home. Note the operative words: properly installed and operated. No matter how intelligent the device, human oversight is critical.

Meet your new best friend, the irrigation controller.


  • Controllers determine which areas get watered when and for how long.
  • Programs are zones grouped together to run consecutively.
  • Zones are groups of plant material irrigated at the same time.

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