Know your backflow

A backflow preventer keeps the water sitting on your lawn from flowing back into your home through your indoor taps.

Sprinkler heads are relatively simple contraptions. When the irrigation system is running, they channel pressurized water through a nozzle and onto your landscape.

But what happens when the sprinkler system isn’t running? Those same sprinkler heads are now conduits for dirt, chemicals, and all manner of pathogens to seep silently into your underground pipes. Contaminants are usually flushed out by pressurized water when your irrigation system clicks on — unless there’s a dramatic drop in water pressure in your neighborhood.

In that case, water can instead flow backwards, potentially escaping your irrigation pipes and flowing into city utility lines that deliver clean, potable water.

backflow removal, maintenance, DIY, how-to | SAWS Garden Style Conservation Water Saver San Antonio Texas

That’s why backflow preventers are crucial — and required by city ordinance to be installed on all residential and commercial irrigation systems.

More commonly known as a double-check valve assembly, this mechanical device works by means of two one-way valves that allow water to enter, but not exit, your irrigation pipes. This effectively isolates the sprinkler system from the clean, potable water flowing into your house and prevents any cross-contamination should a low-pressure event occur.

For those with septic systems, since cross-contamination with your septic tank is a possibility, the state requires a similar device that adds a higher level of protection via an apparatus called a reduced pressure zone backflow assembly, or RPZ for short.

Of course, a backflow assembly only operates as well as it is maintained so it’s equally important to have it inspected, tested, and serviced annually by a Texas-licensed backflow assembly tester.

Also, knowing where your backflow preventer is located, keeping the area clean and clear of excess dirt and debris, understanding how to operate the valves, and protecting it from freezing weather should all be part of your routine sprinkler maintenance throughout the year.

Making sure all backflow prevention devices on your property work properly is a shared responsibility to keep our community safe.

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Seth Patterson
A naturalist by nature, Seth spent his early childhood crawling through creeks and caves of the Hill Country before moving to South Texas where he found his passion in nature photography. Now an avid scuba diver and underwater photographer, Seth follows the water wherever he lands and truly takes to heart his role as a conservation consultant for San Antonio Water System.
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