Rain Sensor or Soil Moisture Sensor

If you have an automatic irrigation system, Florida law requires that it be equipped with a working sensor that interrupts the system when significant rainfall occurs. The rain sensing device is required regardless of the date the system was installed. Currently, there are two types of devices that meet the state requirement: rain sensors and soil moisture sensors.

Not sure which is right for your landscape? Use this comparison chart to help you decide. 

 

Rain Sensor

Soil Moisture Sensor

Number of Units Needed

1

1

(1 for turf; 1 for non-turf)

Wired Models Available

Yes

Yes

Wireless Models Available

Yes

Yes

Variance Allowed for

Flexible Scheduling

No

Yes

Estimated Cost

$30 - $50 per unit

$100 - $450 per unit

Estimated Reduction in

Water Use

Up to 34%, based on

settings and conditions

Up to 50%, based on

settings and conditions

Maintenance Schedule

Check every 6 months;

clear expanding disks

Annual recalibration

Replace Unit/Parts

1 – 3 years or as

specified by manufacturer

As needed or as

specified by manufacturer

Installation Site

Mounted to structure

Buried in root zone

Installation Requirements

Open sky above sensor to

allow for unimpeded access for rainfall

  • Area with significant sun exposure
  • A lot-specific high point
  • In soil with low level of void space, unless all soil is loose
  • In area that receives an average of slightly less level of irrigation
  • 5 feet from property line, structures, impervious surfaces, swales/drainage, and natural depressions

 

The University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) has a library of research-based lawn and garden publications available online. Read timely publications about rain sensors, soil moisture sensors, irrigation requirements for Florida lawns, and much more.