Irrigation Troubleshooting: 5 Signs Your Drip System Needs Attention Before Summer Hits
Your drip irrigation system is the lifeline of your landscape. Every tree, shrub, and ground cover in your yard depends on it for survival during the six months of the year when Phoenix receives virtually no rainfall. When the system is working properly, you barely think about it. When it is not, you find out the hard way: a dead tree, a scorched hedge, or a water bill that suddenly doubles.
The worst time to discover an irrigation problem is mid-July, when daytime temperatures are pushing 115 degrees and your landscape has zero tolerance for missed waterings. The best time to catch and fix these issues is right now, before the extreme heat arrives. In this guide, we walk through the five most common signs that your drip irrigation system needs attention, explain what causes each problem, and tell you how to fix it before summer puts your landscape at risk.
How Drip Irrigation Works in Phoenix Landscapes
Before we get into troubleshooting, it helps to understand the basics. A drip irrigation system delivers water slowly through a network of tubing and emitters placed at individual plants. Unlike spray irrigation used for lawns, drip systems apply water directly to the root zone with minimal waste from evaporation or runoff.
A typical residential drip system in the Valley consists of a valve (usually controlled by a timer or smart controller), a filter, a pressure regulator, main supply tubing (usually half-inch or three-quarter-inch polyethylene), smaller distribution tubing (quarter-inch spaghetti lines), and emitters rated at specific flow rates, typically 1, 2, or 4 gallons per hour.
Each of these components can fail, and the signs of failure are not always obvious. That is why a systematic check of your entire drip system at the start of each irrigation season can prevent costly landscape losses.
Sign 1: One Plant Is Dying While Its Neighbors Are Fine
This is the most common drip system symptom homeowners notice, and it almost always points to a localized emitter or tubing problem. If a single tree or shrub is wilting, dropping leaves, or showing canopy decline while the plants on either side of it look healthy, the first thing to check is whether that plant is actually receiving water.
Common Causes
Clogged emitter. Phoenix’s hard water is loaded with calcium and mineral deposits that accumulate inside emitters over time. A completely clogged emitter delivers zero water to the plant. Partially clogged emitters deliver a reduced flow that may not be enough during summer.
Disconnected spaghetti line. The quarter-inch tubing that runs from the main line to individual emitters is fragile. Landscapers, kids, pets, and monsoon runoff can pull these lines loose. The line may look connected from above but is actually popped off the barb fitting underground or at the emitter end.
Buried or displaced emitter. Over time, soil, mulch, and rock shift and bury emitters. A buried emitter may still flow, but the water saturates a small pocket of soil right at the emitter rather than spreading to the root zone. In some cases, the emitter gets pushed away from the plant entirely.
How to Fix It
Turn on the zone and inspect each emitter individually. You should see water dripping or flowing from every emitter on the zone. If an emitter is dry, remove it and check for mineral buildup. Soaking clogged emitters in vinegar for several hours can dissolve calcium deposits. If the emitter is damaged, replace it. Check that spaghetti lines are firmly attached at both ends and that emitters are positioned within the drip line of the plant they serve.
Sign 2: Wet Spots or Puddles Where There Should Not Be Any
If you notice an area of your landscape that stays wet, has unusually green or fast-growing weeds, or develops puddles after irrigation runs, you likely have a leak somewhere in the system.
Common Causes
Cracked or split tubing. Polyethylene drip tubing degrades in UV sunlight over time. In Phoenix, tubing that is exposed on the surface rather than buried under rock or mulch can become brittle within a few years. Cracks develop at stress points, fittings, and anywhere the tubing has been kinked or stepped on.
Blown fittings. The barb connections between main line and spaghetti tubing, or between tubing sections, can pop loose if water pressure exceeds the system’s rated capacity. This is more common in systems without a properly functioning pressure regulator.
Damaged valve. A valve that does not close completely will allow water to seep through the system continuously, even when the zone is supposed to be off. You will notice wet areas at the lowest points of the zone, where gravity pulls the residual water.
How to Fix It
Walk each zone while it is running and look for obvious leaks, spraying water, or saturated areas. For underground leaks, look for patches of vigorous growth or wet soil that does not dry out between watering cycles. Replace cracked tubing sections with fresh poly tubing and new fittings. If you suspect a valve issue, turn off all zones and check for water still flowing from any emitters. A valve that weeps when closed needs to be cleaned, rebuilt, or replaced.
Sign 3: Your Water Bill Spiked Without Explanation
A sudden increase in your water bill is a strong indicator that water is going somewhere it should not. In the Phoenix area, irrigation typically accounts for 50 to 70 percent of residential water use during summer, so even a moderate leak can show up clearly on your bill.
Common Causes
Underground mainline leak. A break in the main supply line between the valve and the first emitter can waste hundreds of gallons per watering cycle. These leaks are often underground and not visible from the surface, though you may notice a soggy area or unexplained green patch along the supply line path.
Timer or controller malfunction. A controller that double-runs a zone, skips the rest period between cycles, or fails to shut off a zone will significantly increase water usage. Smart controllers with WiFi connectivity can develop software glitches after firmware updates or power outages that cause them to deviate from their programmed schedule.
Stuck valve. If a valve sticks in the open position, that zone runs continuously until someone notices. On a system with multiple zones, a single stuck valve can add hundreds of dollars to a monthly water bill.
How to Fix It
Compare your current bill to the same month in previous years. A spike of 20 percent or more warrants investigation. Run each zone individually and inspect for leaks, then turn all zones off and check your water meter. If the meter is still spinning with everything off, you have a leak between the meter and the valves, which may require a plumber rather than an irrigation repair.
Check your controller’s run log if it has one. Smart controllers keep records of actual run times that you can compare to the programmed schedule. Reset the controller to factory settings and reprogram if you suspect a software issue.
Sign 4: Low Pressure Across an Entire Zone
When you turn on a drip zone and the emitters are barely producing flow, or emitters at the end of the line produce nothing while emitters near the valve work fine, you have a pressure or flow problem.
Common Causes
Clogged filter. Every drip system should have a filter between the valve and the first emitter. Filters catch sediment, mineral particles, and debris before they reach the emitters. A clogged filter restricts flow to the entire zone. In Phoenix’s hard water, filters can clog within a single season if not cleaned regularly.
Partially closed valve. If someone manually adjusted a valve and did not open it fully, the entire zone will operate at reduced pressure. This can also happen when a valve’s solenoid is partially stuck.
Too many emitters on one zone. Over the years, homeowners and landscapers add plants and emitters to existing zones without accounting for the zone’s total flow capacity. Each zone has a maximum flow rate determined by the valve size, supply line diameter, and water pressure. Exceeding that capacity means every emitter on the zone gets less water than it should.
Pressure regulator failure. Pressure regulators can fail in either direction. If one fails in the closed or restricted position, flow drops. If it fails open, full line pressure hits the drip system, which can blow fittings and damage emitters.
How to Fix It
Start at the filter. Remove it, clean or replace the screen, and test the zone again. If flow improves, the filter was the problem, and you should plan to clean it at the beginning and middle of each irrigation season.
If the filter is clean, check the valve. Open it manually using the bleed screw or solenoid to confirm full flow is available. If manual operation produces good flow but electric operation does not, the solenoid may need replacement.
For zones with too many emitters, the solution is to split the zone into two separate zones, each with its own valve. This is a straightforward project for an irrigation technician and solves the problem permanently.
Sign 5: Uneven Watering Across the Landscape
If some plants on the same zone look overwatered while others look parched, the system is delivering water unevenly. This is common in older systems and in systems that have been modified over the years without a cohesive plan.
Common Causes
Mismatched emitter sizes. A zone with a mix of 1 GPH, 2 GPH, and 4 GPH emitters will water plants at vastly different rates. A tree with a single 1 GPH emitter on the same zone as a shrub with two 4 GPH emitters is getting one-eighth the water, even though both run for the same duration.
Emitter count not matched to plant size. A five-gallon shrub that was planted three years ago may still have the single emitter it came with, even though its root system is now three times larger. Larger plants need more emitters, positioned at the drip line, to deliver adequate water to the expanded root zone.
Elevation changes. In yards with grade changes, emitters at the lowest point receive more water due to gravity, while emitters at the highest point receive less. This effect is more pronounced in systems without pressure-compensating emitters.
Long runs of spaghetti tubing. Quarter-inch tubing experiences significant friction loss over distance. Emitters at the end of a long spaghetti run (more than five to six feet) will flow at a lower rate than emitters close to the main line.
How to Fix It
Audit the entire zone. Count the emitters at each plant, note their flow rates, and compare the water delivery per plant. A mature shade tree should have four to six emitters rated at 2 to 4 GPH, while a small shrub may only need one or two emitters at 1 to 2 GPH.
Upgrade to pressure-compensating emitters if your yard has elevation changes. These emitters are designed to deliver a consistent flow rate regardless of pressure variations, which evens out delivery across the zone.
Shorten spaghetti tubing runs to four feet or less. If a plant is farther than that from the main line, extend the main line closer rather than running a long spaghetti line.
Seasonal Maintenance Checklist
Preventing drip system problems is far easier and cheaper than fixing them after they have damaged your landscape. Run through this checklist at least twice a year, once in early spring before summer and once in early fall.
Flush the system. Open the end caps on each main line and let water run through for 30 seconds to flush accumulated sediment and mineral deposits.
Clean or replace filters. Remove the filter screen and rinse it thoroughly. If the screen is damaged or the housing is cracked, replace the entire filter assembly.
Inspect all visible tubing. Walk each zone looking for cracks, kinks, disconnected fittings, and tubing that has been displaced by landscaping, animals, or erosion.
Test each emitter. Turn on each zone and verify that every emitter is flowing. Mark any clogged or broken emitters for replacement.
Check the controller. Verify that the programmed schedule matches the current season’s watering needs. Replace the controller’s backup battery annually.
Adjust emitter placement. Move emitters outward to match the current drip line of growing trees and shrubs. Add emitters to plants that have outgrown their original irrigation setup.
When to Call a Professional
Some irrigation issues are straightforward enough for any homeowner to handle. Replacing a clogged emitter or reconnecting a spaghetti line takes five minutes and costs a few dollars. But other problems, like underground mainline leaks, valve failures, pressure regulation issues, and zone capacity redesigns, require specialized tools and expertise.
At Adaptive Plant Health & Weed Solutions, we evaluate irrigation systems as part of our comprehensive plant health assessments across the Phoenix metro area, including Tempe, Chandler, Gilbert, Mesa, and Scottsdale. An irrigation system that is not delivering water where your plants need it undermines every other aspect of plant care. We can identify the problem, recommend the fix, and make sure your landscape is set up to survive the summer.
Frequently Asked Questions
How often should I check my drip irrigation system?
Perform a full inspection at least twice a year: once in early spring before summer heat arrives and once in early fall. During summer, do a quick visual check once a month by running each zone and walking the property to verify emitters are flowing and there are no visible leaks. Catching problems early prevents plant loss.
Why are some of my drip emitters not working?
The most common cause is mineral buildup from Phoenix’s hard water, which clogs the emitter’s internal passages. Other causes include disconnected spaghetti tubing, buried or displaced emitters, and emitters damaged by foot traffic or landscaping equipment. Remove clogged emitters and soak them in white vinegar for several hours to dissolve mineral deposits, or replace them.
How do I know if my drip system has a leak?
Look for unexplained wet spots, unusually green weed patches, puddles after irrigation runs, or a sudden spike in your water bill. You can also turn off all irrigation zones and check your water meter. If the meter’s flow indicator is still moving, water is leaking somewhere between the meter and your system.
How many drip emitters does a tree need?
It depends on the tree’s size. A newly planted tree in a five-gallon container typically starts with one or two emitters. A mature shade tree needs four to six emitters rated at 2 to 4 gallons per hour, arranged in a ring at the drip line. As the tree grows, add emitters and move them outward to match the expanding root zone.
Should I replace my drip tubing if it looks weathered?
Yes. Polyethylene drip tubing exposed to direct sunlight in Phoenix degrades and becomes brittle within three to five years. If the tubing is discolored, stiff, or cracking at stress points and fittings, replace it before it fails during the peak of summer when your plants cannot afford a missed watering.
Need some help?
At Adaptive Plant Health and Weed Solutions, we offer free consultations to evaluate your irrigation system and ensure that it is set properly. Our focus is on saving water and helping plants to stay healthy and thrive.
Call us at (602) 777-7764 or Contact Us through our online form with any questions or plant healthcare needs.