EPA’s WaterSense program certifies weather-based irrigation controllers, which employ a "smart" irrigation control technology. These systems use local weather data to determine when and how much to water. Drip irrigation systems use 20% to 50% less water than conventional pop-up sprinkler systems and can save up to 30,000 gallons per year by delivering low volumes of water directly to the plant's' roots, minimizing losses to wind, runoff, evaporation, or overspray. Other technologies for reducing water use include control technologies that measure the moisture in the soil and tailor the irrigation schedule accordingly, rain sensors and rainfall shut-off devices that turn off irrigation on rainy days, and rotary spray sprinkler heads that lose less water to evaporation than misters.