According to the EPA, landscape irrigation accounts for almost one-third of all residential water use, totaling more than 7 billion gallons per day. What’s more is that some experts estimate that up to 50 percent of commercial and residential irrigation water use goes to waste due to evaporation, wind, improper system design, or overwatering. In other words, there has to be a better way.
After months of development, the EPA’s WaterSense program has released its first specification for the outdoor irrigation product category. The final specification, announced in early November, covers weather-based irrigation controllers (WBICs), which use local weather data as a basis for scheduling irrigation. Instead of watering based on a preset timer, WBICs are designed to operate based on actual conditions of the site to better meet the needs of plants.
According to the Alliance for Water Efficiency, the performance record of WBICs is somewhat mixed. Some models have performed well in laboratory-like test settings. The largest field study of WBICs to date was conducted in California in 1999, where it was found they reduced irrigation application rates by an average of 6%.
Veronica Blette, chief of EPA’s WaterSense Branch, agrees that some studies have shown mixed performance of WBICs, but adds that the WaterSense label will help ensure that products meet stringent performance and efficiency criteria. “As consumers become more familiar with their WaterSense-labeled controller and use features required by the specification, such as percent adjust, savings should increase,” Blette says.
EPA hopes to see certified WBICs available as early as spring of this year. Blette also says there will be more outdoor irrigation products carrying the WaterSense label in the near future. “When WaterSense started up in 2006, weather-based controllers were the only irrigation product that reasonably met most of [our] criteria,” she says. “Since then, other outdoor products, such as soil moisture-based irrigation controllers, have developed test methods for performance, and we will begin evaluating them for the label.”