Rain Sensors

What are rain sensors?

Many of us have witnessed a neighbor’s sprinkler system running during a rainstorm. Rain sensors prevent this frustrating and wasteful occurrence. These devices are designed to temporarily shut off an irrigation system so it stops running when it detects rain. Rain sensors can be retrofitted on installed sprinkler systems. You may also see them referred to as rain shut-off devices or rain switches.

How do they work?

The most common rain sensor models include an absorbent disk that swells when it gets wet, triggering an electrical switch that overrides the irrigation system. The disk shrinks as it dries out, allowing the system to operate normally. Other models weigh the amount of water collected or use a set of probes to detect the water level.

Wasted water = wasted money. Rain sensors help homeowners to conserve both valuable resources.

SWAT Testing Protocol
SWAT protocols define science-based methods to evaluate whether products meet established standards for water-use efficiency. Version 3.0 of the rain sensor protocol was approved and adopted in October 2009 and is the current testing protocol.

For questions about SWAT or rain sensors, contact the Irrigation Association via email or by calling 703.536.7080.