Rain Sensors

Water Conservation Action No. 4 –
          Enact legislation to require rain sensor shut-off switches
          on new irrigation systems.

In 2004, the Georgia General Assembly passed a law (Georgia Code Section 12-5-6), which requires rain sensor shut-off switches on new landscape irrigation systems for both residential and nonresidential properties within the Metro Water District. The law took effect on January 1, 2005; therefore, all new in-ground residential and commercial landscape irrigation systems in the Metro Water District will have rain sensor shut-off switches. At the local level, building inspection checklists should be updated to reflect rain sensor requirements for new construction with irrigation systems. 

What is a Rain Sensor Shut-Off Switch?

A rain sensor shut-off switch is an electric device that detects and measures rainfall and turns off the irrigation system when a predetermined amount of rain has fallen. This prevents the irrigation system from watering when the landscape is already receiving enough water from the rainfall. Rain sensors reduce unnecessary watering during rainfall events.

Why are Rain Sensor Shut-Off Switches Important?

The outdoor service industry is big business in the Atlanta region. There are over 1,500 outdoor service companies with in the 15-county Atlanta region that employ approximately 13,000 people according to the 2006 Census County Business Patterns. These companies account for 60 percent of the outdoor service companies across the entire state of Georgia. Over 400 companies in the Atlanta region deal directly with installing irrigation systems.
 
When installed on an irrigation system, a rain sensor shut-off switch prevents over-watering and assists with conserving water by reducing water that would be wasted if a lawn was being irrigated and rained on at the same time. The magnitude of companies involved with irrigation suggests that there are many landscape irrigation systems operating in the Atlanta region. The more rain sensor shut-off switches installed on irrigation systems leads to more of the region’s water supply conserved.

Outreach

In April 2006, the District sent out a letter to all of the irrigation companies in the 15-county Atlanta region in an effort to reach out to these companies to ask for help to put this water conservation measure into action. This letter was sent with the support of the Metro Atlanta Landscape and Turf Association and the Georgia Green Industry Association.