SAWS Conservation: Rain Sensors for Sprinkler Systems
Aquifer Beaker

Edwards Aquifer

Aquifer Level 681.5'
6/13/19 - Official

The Edwards aquifer and its catchment area in the San Antonio region is about 8,000 square miles and includes all or part of 13 counties in south-central Texas.

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Year-Round Watering Hours

Watering with an irrigation system or sprinkler is allowed any day of the week before 11 a.m. or after 7 p.m.

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Aquifer Level 681.5 | Year-Round Watering Hours

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Outdoor Conservation

Rain Sensors for Sprinkler Systems

Rain sensors like the one pictured will be required on all existing sprinkler systems as of January 2006. Hydroscopic discs - not collector cups - are required in eligible rain sensors.

Rain sensors like the one pictured are required on all sprinkler systems. SAWS recommends sensors with hygroscopic discs -- not collector cups.

Since 2006, rain sensors have been required on all in-ground sprinkler systems in San Antonio. Rain sensors are designed to override the normal cycle of your irrigation system, shutting it off when an adequate amount of rainfall has been received.

"Rain sensors are a great idea for many reasons," says Dana Nichols, outdoor conservation manager. "They let your sprinklers run only when it's needed which conserves water, saves you money, and protects your lawn from the effects of over-watering.”

If SAWS customers do not have rain sensors and a complaint is made, they will only receive one warning before being issued a water waster ticket. (Note: Watering on the wrong day or time may result in a citation being issued without prior warning, if witnessed in person by an enforcement officer.)

What is a Rain Sensor?
Rain sensors are designed to shut off the common line of your irrigation system and override the cycle of an automatic irrigation system when an adequate amount of rainfall has been received.

How do Rain Sensors Work?
The technology of sensors is quite simple: they interrupt the electrical flow from the controller that would otherwise activate the valve. As a result, no "make-up" watering is done if a scheduled watering is interrupted or deleted all together by the action of a sensor.

Where to install the Rain Sensor?
The closer the rain sensor is to the controller the better. The ideal location for mounting a rain sensor is not always the most practical location. The following locations are recommended:

  • Building roof
  • Light post
  • On or near a satellite dish
  • Fence top
  • Any open area

For more information on the city's conservation ordinance, or details specifically about rain sensors, please read our frequently-asked questions or call us at 210-704-SAVE.