What Is the Most Common Cause of Sprinkler Leakage?
If you’ve noticed damp spots in your yard, water leaking from sprinkler heads long after the system is off, or a spike in your water bill, you might be dealing with a sprinkler leak. It’s a common issue for homeowners and, unfortunately, one that can lead to wasted water, lawn damage, and costly repairs if ignored.
Fortunately, most sprinkler system leaks come from a few predictable sources. And the sooner you identify what’s going on, the easier it is to fix. In this post, we’ll walk through the most common sprinkler leakage causes, explain what they look like, and share how to prevent future problems.
What Counts as a Sprinkler Leak?
A sprinkler leak doesn’t always mean a broken pipe or water shooting into the air. More often, it looks like a sprinkler head leaking water when it shouldn’t be—or water slowly pooling around the lowest point in your yard. In short, any time water is escaping the system when it’s supposed to be off, you’re dealing with a leak.
Understanding the causes of sprinkler leaks is the first step to addressing the problem.
Low-Head Drainage: The Most Common Cause
The most frequent and overlooked cause of sprinkler leakage is something called low-head drainage. After your sprinkler system shuts off, leftover water in the lines naturally flows downhill. If your yard has any slope, that water exits through the lowest sprinkler heads, creating a slow and steady drip.
While it may appear that the sprinkler head is leaking, the real issue is drainage—not damage. In this case, the solution is simple: install sprinkler heads with built-in check valves or add check valves beneath existing heads. These prevent water from draining out after the system shuts off, eliminating the slow leak.
This is one of the most common sprinkler leakage causes, and it’s an easy fix once identified.
Faulty Valves That Let Water Through
Another common source of sprinkler system leaks is a valve that isn’t sealing completely. When this happens, a small amount of water continues to pass through the system—even when it’s not running. That water finds its way to the lowest heads and begins leaking out.
If you’re unsure whether your valves are to blame, try this:
- Turn off all water inside and outside your home.
- Check your water meter. If the small dial (often red) is moving, water is flowing somewhere.
- If the dial is still, your system may be experiencing low-head drainage instead.
Faulty valves don’t always cause visible damage, but over time, they contribute to water waste and can make your lawn appear unevenly watered. They’re a common but often misunderstood cause of sprinkler leaks.
Pipe Corrosion and Underground Leaks
Over time, the pipes that carry water beneath your lawn can corrode, crack, or shift. This can happen due to soil movement, root growth, or just age. Unlike a leaky head, these underground sprinkler system leaks are harder to spot. You might notice unusually wet patches, lower water pressure, or zones that don’t run as effectively as they used to.
Pipe corrosion is one of the more serious sprinkler leakage causes, and it’s best handled by a professional. Identifying the exact location and extent of damage typically requires the right tools and experience.
Damaged or Broken Sprinkler Heads
Sometimes the leak really is the head. Cracked casings, worn seals, or damage from lawn equipment can all lead to a sprinkler head leaking water during or after a run cycle. In these cases, you’ll usually see water puddling around the head, inconsistent spray patterns, or an obvious break.
This is one of the more visible common sprinkler leaks and usually one of the easiest to fix. Swap out the damaged head, and when caught early, it can prevent larger issues in the system.
Why Regular Maintenance Makes a Difference
Routine service is one of the best ways to avoid common sprinkler leaks. During a spring start-up, a technician can spot early signs of valve issues, low-head drainage, or head damage. Seasonal maintenance also keeps your system calibrated and working efficiently throughout the year.
Whether it’s a spring check, a mid-season tune-up, or a winter blowout, regular attention can prevent the most common sprinkler leakage causes from turning into long-term damage.
A Reliable System Starts with the Right Support
At Jones Sprinklers, we believe sprinkler systems should make your life easier, not more stressful. That’s why we’re committed to helping homeowners in Spokane Valley keep their systems efficient, reliable, and leak-free. From diagnosing tricky leaks to installing new components, our team brings both experience and care to every job.
If you’re seeing signs of a leak or just want the peace of mind that comes from a system that’s running right, give us a call. We’re here to help you protect your lawn and your investment, season after season.