By Brent Ehrlich
Rain Bird’s ESP-SMT system uses a tipping rain bucket to measure site-collected rainfall; this data is combined with information on soil and plant type, landscape slope, and other factors to minimize water waste during irrigation.
Nearly 7 billion gallons of water are used in the U.S annually for outdoor residential applications, primarily for landscape irrigation, with up to 50% of this wasted due to overwatering, according to the U.S. Environmental Protection Agency. These numbers stand in stark contrast to the droughts that have devastated much of the U.S. through 2012, but there are signs of hope amidst the parched landscape. Water-conscious property owners and landscape contractors are now going beyond simple water-conservation strategies and are employing “smart” irrigation controllers that automatically adjust irrigation schedules and maximize water efficiency. WaterSense
is now certifying both residential and commercial products using its Specification for Weather-Based Irrigation Controllers.
Smart irrigation controllers are like thermostats that manage water consumption instead of heat, but rather than using just rainfall or soil moisture data, they use complicated evapotranspiration (ET) algorithms based on temperature, humidity, sunshine, wind, and other factors to calculate the amount of water transpired by vegetation and evaporated from the soil. The controllers use ET data to adjust irrigation schedules and provide just the right amount of water to maintain the health of different plant species and avoid overwatering.