Irrigation systems and other types of plumbing are designed for water to flow one way, from the main to outlets such as faucets and drips. Ordinarily, when there’s a problem at the outlet or the pressure in the main drops, water can sometimes go backward, creating backflow. Backflow prevention systems are what stops this problem, which makes them crucial during irrigation installation and use. Here’s what you need to know about these systems.

Why Is Backflow a Problem?

When water flows backwards into the main it came from, it’s rarely as clean as when it left. It may be contaminated with fertilizer, bacteria, pesticide, rust, algae, or just plain dirt. These contaminants then get mixed into the main water supply and come out other faucets—sometimes into a bathtub or drinking glass. 

By including backflow preventers during irrigation installation, your installer keeps the water supply safe for everyone using it. They also protect you from potential legal issues and fines since backflow prevention systems are legally required.

How Do Backflow Prevention Systems Work?

There are many types of backflow preventers designed for different types of irrigation installations. The simplest and most effective is an air gap—a place where the water flows out of a pipe, through open air, and into a receptacle below before traveling further. If this type of system backs up, the water simply overflows from the receptacle instead of flying back up to the pipe it came from.

Other models rely on one-way valves to prevent water from flowing backward. A valve is hinged in such a way that it can only open in one direction. If the pressure reverses and tries to push the valve the other way, it closes. The greater the pressure difference, the more tightly the valve is closed.

Finally, some high-tech systems use multiple valves, pressurized chambers, and devices for monitoring the pressure. These reduced pressure zone devices are used when there’s a major contamination risk and aren’t generally seen in residential irrigation installations.

For skilled lawn irrigation installations complete with built-in backflow prevention, choose Allgreen Irrigation Systems. Based in Cumming, GA, and serving Forsyth County, they have 25 years of experience installing and providing irrigation repairs for commercial and residential systems. They work with trusted manufacturers, including Rain Bird®, Irritrol®, Hunter®, and Toro®. For a free estimate, call (770) 888-9399, or visit them online to learn more about their irrigation systems.