SWAT introduces cost-effective option for testing weather-based controllers

The Irrigation Association’s Smart Water Application Technologies (SWAT) has created a more cost-effective option for weather-based controller testing. Manufacturers can now submit testing data from the U.S. Environmental Protection Agency’s WaterSense program directly to SWAT. This option is only available for smart controllers that have received the WaterSense label.

SWAT is a collaborative initiative between the irrigation industry and water providers, which creates science-based testing protocols to evaluate the water-use efficiency of irrigation products. Manufacturers voluntarily submit their products to third-party testing agencies and pay a fee to underwrite the cost.

Test results are posted on SWAT’s website (www.swatirrigation.org) and are used by irrigation professionals in the field when selecting products for specific projects. SWAT reports are also used by many water providers as the basis for consumer rebates on irrigation products.


SWAT vs. WaterSense

SWAT’s protocols have been referenced by the EPA WaterSense program, which develops specifications for product labeling. Like SWAT, manufacturers pay a fee for testing to verify if their products meet WaterSense requirements. While the two programs are complementary, there are significant differences.

For example, EPA’s specification for weather-based irrigation controllers references the related SWAT testing protocol but defines additional criteria to qualify for the WaterSense label. The two programs define different requirements for the testing process, including:

  • Number and depth of rain events
  • Minimum run time for sprinklers
  • Guidelines for missing weather station data
  • How rainfall is accounted for in the daily soil moisture balance

In addition, unlike SWAT, EPA defines minimum criteria for efficient products. To qualify for the WaterSense label, a weather-based controller must maintain at least 80 percent irrigation adequacy (enough water so plants are not harmed) and minimize excess water application to less than 10 percent for an individual zone and less than 5 percent excess overall.

Deliverables from each program’s testing also vary. Rather than providing specific pass/fail recommendations, SWAT publishes a detailed performance report, allowing the designer, contractor, water agency or consumer to decide if a product meets their criteria. In contrast, EPA awards the WaterSense label to products that meet its specifications but does not provide detailed testing results.


Although many of the weather-based controllers tested by SWAT — and most of the newer product introductions — have obtained the WaterSense label, there is still demand for detailed test results. Many manufacturers that have obtained the WaterSense label have expressed interest in having their test results reported on the SWAT website without paying additional testing fees.


The cost-effective testing option

Given continued demand for detailed testing results, a working group of volunteers from both industry and water providers has agreed to implement an option that will use the data collected for the WaterSense program to create a SWAT-style report. Manufacturers will be able to minimize testing costs while ensuring that performance results for their newer models of weather-based controllers are available for water agencies, designers, contractors and end-users.

Under the new testing option:

  • A SWAT technical expert will analyze data from an accredited EPA WaterSense testing facility, with manufacturer authorization.
  • Results will be shared with the manufacturer and, if approved, will be published on the SWAT website.
  • Each report will include irrigation adequacy and excess, number of irrigation days, models using the tested technology, and WaterSense label status.
  • Reports will be available on the SWAT website for three years or until the product is no longer in production.
  • Products must be re-tested every three years.

To qualify for the program, weather-based controllers must be currently available in the marketplace. Manufacturers will pay only $500 per model for the optional technical review, a significant savings over traditional SWAT testing.

Reports will be posted on the SWAT website, with more recent test results listed first. Products from Irrigation Association members will also be highlighted. To make sure the site reflects the latest product models and technology innovations, test results that are currently posted on the site but are older than three years will be removed on Oct. 1, 2015.

For more information on the optional path for testing, visit www.swatirrigation.org or contact IA Industry Development Director Brent Mecham (brentmecham@irrigation.org; 703.536.7080).