How to Find a Leak in Your Irrigation System

Geysers belong in national parks, not your lawn

A sprinkler system watering a backyard
Photo: MaYcaL / iStock / Getty Images Plus / Getty Images
A sprinkler system watering a backyard
Photo: MaYcaL / iStock / Getty Images Plus / Getty Images
Rachel Presser
Written by Rachel Presser
Contributing Writer
Updated December 1, 2023

Difficulty

Simple

Saturday skill builder.

Time to complete

2 hours

You’ll need about 30 to 45 minutes to use the water leak microphone to detect leaks and another 20 minutes per sprinkler head replacement.

Cost

$15–$75

You’ll wonder why everyone doesn’t do this themselves.

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What you'll need:

TOOLS
  • Water leak microphone
  • Small gardening spade
SUPPLIES
  • Replacement sprinkler heads

Sprinkler systems can save so much time while giving you a lush green lawn (no more lugging around the hose). But sometimes, they just don't feel like producing that emerald carpet and instead decide to burst, sending water into the sky like your yard is the lobby of a Las Vegas destination hotel. While this is an obvious sign that your sprinklers are leaking, there are also more subtle signs of a leak to be aware of. We'll show you how to find a leak in an irrigation system and the telltale signs to watch out for.

Before You Find a Leak in Your Irrigation System

Sometimes, the signs of a sprinkler past its prime are obvious, like a gushing geyser that practically brings tourists to your block. But if your water bills are unusually high, you should rule out if you have an indoor plumbing problem. Otherwise, you likely have a leak in your system.

Before you call a local plumber to investigate, look for the leak yourself. Shut off your water meter and give it a couple of minutes. If the needle on the meter shows that there's water usage even though everything was just turned off, you've definitely got a leak. Look for the signs of an indoor leak, like wet carpet, water seeping out from your toilet's base, and walls that feel like a soggy newspaper if you poke them. Once you've ruled out an indoor leak, it’s time to look for the signs that your irrigation system is leaking.

  1. Check Your Sprinkler Valves

    A person inspecting a sprinkler system’s valve
    Photo: mgstudyo / iStock / Getty Images Plus / Getty Images

    The first step in your detective work to find a leak in your irrigation system is to look at the valve boxes for your sprinklers. You should have a rough map or schematic showing the location of all the valve boxes for each sprinkler in your system. The company that installed the sprinkler system should have it available if they didn’t give it to you after installation. If the sprinkler system came with your home upon moving in, you can contact them for this map.

    A functional sprinkler box is bone-dry. Wet valve boxes are a sign something is wrong. Inspect wet units for loose wires, worn or broken parts, and fittings that have water seeping in or out. This could be the source of the leak.

  2. Investigate Each Sprinkler by Zone

    Once you've ruled out worn or malfunctioning valve boxes, the sprinklers themselves can offer more clues that there's a water leak in your irrigation system.

    Shooting geysers are the most obvious clue—it usually means that a sprinkler head is broken. Sprinkler heads can also get knocked off during routine lawn care, or by a curious pet or wild animal. These signs aren't as immediately visible:

    • Pooling around the sprinkler base. Flooded sprinkler bases often indicate older valves that don't shut off correctly, and this becomes more apparent if one zone is flooding, but the others are not. If the areas between sprinklers look flooded, it could also spell a leak.

    • Water sprays between sprinkler heads. A steady misting is great on vacation but not in your irrigation system. Water that continuously sprays out between sprinkler heads is typically a sign of a broken sprinkler line.

    • Spurts of water gush out at the sprinkler base. This is different from flooding and spraying. It looks more like the gurgling cascade one sees when a bowl overflows with water in the sink. If this is happening at the sprinkler base, it's often a broken seal preventing the water from going to the nozzle.

    If you don’t see any of these signs, wave the sensory rod in the water leak microphone in areas with sprinkler heads, valve boxes, or water lines. Use your schematic of the irrigation system as a guide so you have a good idea of where to wave the sensory rod. This microphone detects the sound of water moving where it shouldn’t be, since it’s often at a frequency we can’t hear unless it’s a deluge like a fire hydrant or forming a pool with audible drips. They’re strong enough to hear underground where human ears can’t unless you have superpowers worthy of a cinematic universe.

    If an area of your lawn seems unusually lush or wet though, that’s probably the source of the leak, and you can confirm by waving the microphone’s sensory rod where your footsteps squish.

  3. Examine the Sprinkler Heads

     A man examining a sprinkler head
    Photo: BillionPhotos.com / Adobe Stock

    After looking at each sprinkler zone and the bases of each one, the sprinkler heads are the next item that will confirm if you’ve got a leak in your irrigation system. While there are different types of sprinkler heads, it’s easy to tell when something is wrong with an individual sprinkler head no matter what kind it is.

    Clogs, water line disruptions, and broken or missing parts can cause low water flow or other improper spraying. Some of your sprinkler heads might still be functional, but one or a few might be broken, causing the leak.

    If it’s just the sprinkler heads that are broken, use a spade to dig around them and replace the broken heads. If the leak persists, the sprinkler heads weren’t the only problem.

  4. Turn Your Sprinkler System Off

    Just like how you shut the water off earlier to confirm that the leak wasn’t coming from inside the house, now it’s time to turn the sprinkler system off. You certainly have a leak if there are patches of your lawn that feel more like a swamp between watering cycles.

    It’s possible for irrigation systems to leak even if they’re turned off. If yours is still leaking despite being turned off, it's often a malfunctioning valve. They wear down and break over time and could be due for replacement. Debris can also get trapped in the sprinkler system's mechanisms and cause water to leak through the valves.

    Low-head drainage can also cause water to leak from your sprinklers even if they're off. Water drains from the lowest head in the system after a cycle completes and is one of the top causes of leakages that still occur after being turned off. Puddles in the lowest point of your yard are the telltale sign low-head drainage is the culprit.

DIY vs. Hiring a Pro 

If your irrigation system is leaking, the cause and severity ultimately determine whether you can take care of it yourself or need to hire a local sprinkler repair service.

It costs about $15 to $50 to buy a basic water leak microphone, but it may not always be accurate if you can't palpably feel or see wet patches. More complex acoustics systems are often untenably expensive for the average homeowner.

Replacement sprinkler heads run from $2 to $15 apiece if you’re installing them yourself. Professional replacement is about $65 to $90 per sprinkler head, and sprinkler head installation costs $90 to $110 each.

Diagnosing the problem can be difficult, and you can end up buying new sprinkler heads just to find out a water line ruptured. While it's safe to replace sprinkler heads yourself, professionals should handle any problems with the irrigation system's mechanics or water lines. This is because these lines need to be dug underground and connected to your water supply. Cutting water lines can easily create an expensive, waterlogged disaster.

If the problem ends up being simple, like a clogged sprinkler head or worn valve, the cost is likely to be $50 to $100. Your repair costs can be between $150 to $400 for more complex jobs, like fixing broken pipes or water lines.

Frequently Asked Questions

The pipe trenches for an in-ground irrigation system should be at least seven inches underground, but no more than 10 inches. Seven to 10 inches is the sweet spot for irrigation line depth because the pipes can crack if they're too close to the surface. If the lines are installed too deep, it becomes much harder to detect leaks and the condition the pipes are in.

Need professional help with your project?
Get quotes from top-rated pros.
Learn more about our contributor
Rachel Presser
Written by Rachel Presser
Contributing Writer
Rachel Presser is an experienced writer teaching homeowners how to navigate HOAs, home insurance, and local laws when taking on home improvement projects. She holds both a bachelors and master's in accounting and can explain the income tax impacts of homeowner transactions. Her work can be found in other publications like Home Stratosphere and LA Digs.
Rachel Presser is an experienced writer teaching homeowners how to navigate HOAs, home insurance, and local laws when taking on home improvement projects. She holds both a bachelors and master's in accounting and can explain the income tax impacts of homeowner transactions. Her work can be found in other publications like Home Stratosphere and LA Digs.
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