Rain Sensors Can Conserve Water; Sensors Next for SWAT

Rain sensing shutoff devices for irrigation systems have potential to save significant amounts of water, said a researcher who created the first draft of testing protocols for rain sensors for the industry.

Rain sensors are the second product category taken on by the Irrigation Association’s Smart Water Application Technologies program, which facilitates third-party testing of products with water-saving potential and promotes the use of proven water-saving technology.

Weather-based irrigation controllers were the first technology adopted by SWAT, a consortium of water utilities and others in the irrigation industry interested in advancing the use of efficient irrigation technology. Weather-based controllers, known as smart controllers, schedule irrigation based on detailed information about site conditions.

“Through SWAT the irrigation industry has taken a strong role in shaping standards that will come anyway,” said Irrigation Association Executive Director Deborah Hamlin. “The EPA WaterSense labeling program is looking at SWAT as a model for specifications for smart controllers. SWAT’s rain sensor protocols will lay important groundwork in that category as well.”

University of Florida researcher Michael Dukes spoke to more than 60 attendees at the SWAT rain sensor meeting in Gainesville, Fla. The payback in savings from installing an effective rain sensing shutoff device is generally less than a year because the devices are relatively inexpensive, Dukes said.

The group reviewed protocols and discussed obstacles to the acceptance of rain sensors, including variations in performance over the lifespan of the product and responses to humidity and rainfall intensity. The technology promotion campaign will focus on helping contractors and consumers understand potential water savings and the consumer’s role in conserving water with sensors.

SWAT is seeking comments on draft protocols for rain sensor tests. The protocols are posted on the Irrigation Association Web site,
www.irrigation.org/gov/swat_drafts-rainsensor.htm.