Why Is My Sprinkler Head Leaking? (And How to Fix It Fast)

If you’ve spotted a sprinkler head leaking water in your yard even when the system is off, you’re not imagining things — and you’re not alone. It’s one of the most common calls we get from homeowners in Denver, Aurora, and Highlands Ranch during the summer watering season. A leaking head wastes water, drowns your lawn in one spot while starving another, and — under Denver’s current Stage 1 drought restrictions — it’s actually something you’re required to fix quickly.

The good news is that most leaks come from a short list of causes, and many are easy to diagnose once you know what to look for.

Cause 1: Low Head Drainage

This is the most common reason for a slow drip after the system shuts off. If a sprinkler head sits at the lowest point of its zone, water left in the pipe drains out through it simply because of gravity. You’ll usually notice a small wet spot or puddle that shows up a few minutes after the system runs, then stops. A check valve installed in that head usually solves it for good.

Cause 2: A Valve That Won’t Fully Close

Every zone has a valve that opens to let water through and closes when the cycle ends. Over time, the rubber diaphragm inside can wear out or get stuck open by a piece of grit. When that happens, water keeps trickling through the pipes and out the lowest heads in the zone, even hours after the system should be off.

Cause 3: A Cracked Head or Worn Seal

Colorado’s freeze-thaw cycles and intense sun are tough on plastic sprinkler heads. Cracks can form from age, UV exposure, or a run-in with a lawn mower. Even a hairline crack near the base will let water seep out continuously, and it usually gets worse over a season, not better.

Cause 4: Dirt, Sand, or Mulch Stuck Inside the Head

Debris that works its way into a sprinkler head can prop the internal seal open just enough to cause a steady drip. This is common in yards with a lot of foot traffic or loose mulch near the heads.

Cause 5: A Head That’s Knocked Off-Level

Sprinkler heads need to sit level with the ground to seal properly. If one gets bumped by a mower, a dog, or foot traffic, it can tilt just enough that it won’t close all the way, leading to a leak that looks worse right after mowing.

Why You Shouldn’t Let It Wait This Summer

Denver Water’s Stage 1 drought restrictions are in effect for the 2026 season, limiting most homes to two watering days a week and asking customers to cut total water use by at least 20%. As part of those rules, homeowners are required to repair leaking sprinkler systems within 10 days of discovering the problem. That means a leaking head isn’t just a nuisance — it’s something the city expects you to address quickly, and it’s also quietly running up your bill every single day it’s ignored, since it keeps dripping between cycles whether you notice it or not.

Quick Checks You Can Do Yourself

Before calling for help, a homeowner in Wheat Ridge or Littleton can usually narrow things down in a few minutes:

Run each zone manually and watch for water bubbling up around a head after the cycle ends. If it stops within a minute or two, it’s likely low head drainage.

Feel around the base of the head for cracks or a head that wiggles more than it should.

Check right after mowing to see if a leak appears only after the yard’s been cut — that points to a knocked-over or misaligned head.

Look for water pooling in the same spot every time, which usually means a valve issue rather than a single bad head.

When to Call a Professional

Low head drainage and a single cracked head are often simple, inexpensive fixes. But if you’re seeing water at multiple heads across a zone, a valve that won’t shut off completely, or a wet spot that shows up even when the system hasn’t run in days, the problem is likely underground — a broken pipe, a failing valve, or a wiring issue at the controller. Those aren’t easy to diagnose without pulling up sod, and getting them wrong can mean digging in the wrong spot.

A leaking sprinkler head is rarely a sign of a major problem, but in a drought year, it’s not one to put off. A quick inspection now can save water, protect your lawn, and keep you on the right side of Denver’s watering rules.

Frequently Asked Questions

Is it normal for a little water to drip from a sprinkler head after it shuts off?

A small amount of drainage for a minute or two, especially from the lowest head in a zone, is common and usually just low head drainage. A steady drip that continues for longer, or water that appears hours later, points to a valve or head problem worth checking.

Can a leaking sprinkler head really raise my water bill?

Yes. A head that drips between cycles is using water every day, not just during scheduled watering times, and that adds up over weeks without you noticing.

How long do I have to fix a leak under Denver’s current watering rules?

Denver Water’s Stage 1 drought restrictions ask homeowners to repair leaking irrigation systems within 10 days of finding the problem.

Do I need to replace the whole sprinkler head, or can it be repaired?

It depends on the cause. Low head drainage can often be solved by adding a check valve to the existing head, while a cracked head or worn seal usually just needs the head itself replaced. Valve or underground pipe issues require a closer look before knowing the fix.

If you’ve got a sprinkler head that won’t stop dripping, don’t wait out the 10-day window to find out why. Contact Apex Irrigation and we’ll track down the cause and get it fixed before it wastes another drop.