Backflow Preventers on Fort Worth Sprinkler Systems: What Homeowners Should Know

Every sprinkler system connected to Fort Worth’s water supply needs a backflow preventer. It is usually the brass assembly near the house or the meter, with two valves and a few small test ports. Most homeowners never think about it until it leaks or cracks in a freeze. This article explains what it does, what the city requires and how to take care of it.

What Backflow Is

Normally, water flows from the city main into your home and your sprinkler system. Under certain conditions, water can flow the other way. That is called backflow. It can happen in two main ways:

• Backsiphonage: a drop in pressure in the city main, such as during a main break or heavy fire hydrant use, can pull water backward out of your plumbing.
• Backpressure: pressure on your side becomes higher than the supply pressure and pushes water back.

Sprinkler water sits in pipes buried in soil that may contain fertilizer, pesticides, animal waste and bacteria. Without protection, that water could be drawn back into the drinking water supply.

What a Backflow Preventer Does

A backflow prevention assembly allows water to flow in one direction only. If pressure conditions change, internal check valves close and stop reverse flow. Common types for residential irrigation include double check valve assemblies, pressure vacuum breakers and reduced pressure zone assemblies. The type required depends on the hazard and local rules.

What Fort Worth Requires

Fort Worth’s backflow and cross-connection program sets these rules for irrigation systems:

• Any irrigation system connected to a public or private potable water supply must be connected through an approved backflow prevention assembly.
• The assembly must appear on the city’s list of approved assemblies.
• All new installations, relocations, replacements or removals require a plumbing backflow permit.
• Assemblies must be tested upon installation or repair by a licensed Backflow Prevention Assembly Tester registered with the Fort Worth water utility, with results submitted through the city’s testing system.
• Commercial irrigation assemblies are tested every year.

The city’s irrigation code also calls for an isolation valve between the water meter and the backflow preventer on all irrigation systems. Our article on backflow testing in Fort Worth covers the testing process.

Where Your Backflow Preventer Is

Most residential assemblies sit above ground near the house, often next to the foundation, or near the water meter. They are installed above ground so they can be tested and so any discharge can drain away. Find yours and learn how to close its shutoff valves; they are an easy way to shut off the sprinkler system in an emergency.

Common Problems

Leaks

Drips or sprays from the assembly can come from worn seals, debris in a check valve, a cracked body or loose fittings. See our article on a leaking backflow preventer.

Freeze damage

Because it sits above ground and holds water, the backflow preventer is the part of the system most likely to crack in a hard freeze. Our guide on protecting your backflow preventer from freezing explains what to do before cold weather.

Low pressure

A partly closed shutoff valve or internal damage can restrict flow to the whole system. See our guide on low sprinkler pressure.

Tampering or theft

Brass assemblies are sometimes stolen for scrap. A locking cage or cover can help.

Why Homeowners Should Not Repair It Themselves

Because the backflow preventer protects the public water supply, Fort Worth requires permits for replacement and relocation, and testing by a registered tester after installation or repair. Taking it apart, replacing internal parts or swapping the assembly without the right permit and test can lead to problems with the city and leaves the water supply unprotected. Leave repairs to licensed professionals.

What Homeowners Can Do

• Know where it is and how to shut its valves.
• Look at it a few times a year for drips, cracks or damage.
• Keep it clear. Do not bury it in mulch or let shrubs grow over it; testers need access.
• Protect it in freezing weather with an insulated cover.
• Call for help when it leaks.

Test Cocks and Handles

The small screws on the side of the assembly are test cocks, used by testers to check each check valve. Leave them alone. The larger handles are the shutoff valves. On most assemblies, the valves are open when the handles run parallel to the pipe and closed when they are perpendicular.

Covers, Cages and Enclosures

Many homeowners like to hide the backflow preventer. That is fine as long as the cover does not get in the way of testing or drainage. Insulated fabric covers are useful in winter and easy to remove. Rigid enclosures and locking cages protect against theft and damage from mowers and vehicles. Fake rocks and decorative boxes work too, but make sure they lift off easily. Avoid anything that seals the assembly in tightly, and never bury it. A tester needs to reach the test cocks and handles, and some assembly types need open air around them to work correctly.

Moving or Changing the Assembly During a Remodel

Adding a patio, pool or room addition sometimes puts the backflow preventer in the way. Moving it requires a permit and a new test, so bring it up early with your contractor.

When to Call a Technician

If your backflow preventer leaks, cracked in a freeze, or needs to be moved during a remodel, our sprinkler repair team can help arrange the repair, permit and testing. See our zone-by-zone check for how to include it in a yearly inspection.