By Lori D. Palmquist, CID, CIC, CLIA, CLWM
It is a generally accepted statistic that we over water our landscapes by a margin of 200%.
Smart controllers, also known as ET controllers and weather-based controllers, respond to daily changes in the weather by adjusting either the run time of the individual irrigation zones, or the watering days, or both.
Smart controllers are the future of irrigation scheduling with some states already requiring them for new landscape installations. There are also many rebate programs offered by cities and water purveyors for retrofitting this technology into existing systems.
An important point needs to be made here: Inefficient, problem-riddled irrigation components will not magically improve their performance, if a smart controller is installed. A smart controller will very quickly reveal the weaknesses of an inefficient or faulty system.
There are two sources of weather data that inform smart controllers. One is professional grade, off-site weather stations. The smart controllers that access off-site weather data often have a small monthly fee for the acquisition and delivery of the data. The other source of weather data is on-site weather sensors, monitors, and soil-moisture sensors. This strategy involves buying the equipment up front, with no on-going, data-service fees.
There are more than 30 weather-based smart controllers and 8 soil-sensor-based controllers on an approved list from Smart Water Application Technologies (SWAT). It can be daunting to know how to decide which controller would be the most appropriate in any given situation. Following are some factors to consider when deciding which controller is best for the job:
· Size of landscape
· Number of controllers needed for the landscape
· Ability of a pager or cell phone tower signal to reach the controller (signal strength)
· Importance of accuracy of the data
· Whether up-front costs (on-site data gathering) or on-going fees (off-site data gathering) are preferred
· Whether you are hands-on, or want the installer to monitor and maintain the system
· Which controller you (or the installer) feel confident using
Good Tip: The best way to determine which controller to choose is to consult with someone in your
area who has hands-on experience with a number of different controllers. Contacting a local water
purveyor, professional irrigation supply store, or landscape contractor trade organization, are a few possibilities.
Know that there is a learning curve to understand installation, usage, and monitoring of irrigation systems that use smart technology. Many manufacturers offer extensive tutorial videos and literature on their websites. The manufacturers’ reps and technical support crews are also extremely helpful in ensuring that the controllers are installed and monitored properly.
Lori Palmquist is an irrigation designer, consultant, and educator in the East Bay. She is an avid spokesperson for water efficiency in the landscape.