Why isn't my sprinkler system watering evenly?

Uneven watering is typically caused by clogged nozzles, misaligned sprinkler heads, pressure imbalances between zones, or worn-out components. In Arizona's hard water conditions, mineral buildup frequently blocks spray patterns.

How can I tell if my sprinkler heads are clogged?

Look for reduced spray distance, distorted spray patterns, or dry spots in your lawn. You may also notice water pooling around certain heads while others barely spray.

Can low water pressure cause uneven watering?

Yes, low pressure prevents sprinkler heads from operating at their designed range, creating dry spots. Pressure issues can stem from mainline leaks, partially closed valves, or too many heads on one zone.

How often should I check my sprinkler system for even coverage?

In Arizona, inspect your system monthly during active watering seasons (March-October) and perform a catch-cup test quarterly to measure distribution uniformity.

Why Isn't My Sprinkler | Arizona Irrigation Repair LLC

Common Causes of Uneven Sprinkler Coverage

If you're noticing dry brown patches next to soggy areas, your sprinkler system isn't distributing water evenly. This wastes water, raises your utility bill, and stresses your desert landscaping. In Arizona's challenging climate, even small irrigation problems quickly damage turf and plants.

1. Clogged or Dirty Sprinkler Heads

Arizona's hard water contains high mineral content that builds up inside nozzles and filters. Dirt, grass clippings, and debris also block spray patterns. A clogged head sprays unevenly or not at all, leaving dry spots while adjacent areas get too much water.

Solution: Remove and clean each sprinkler head, flush the system, and install inline filters to prevent future buildup.

2. Misaligned or Damaged Heads

Sprinkler heads can shift from foot traffic, lawn mowers, or settling soil. Broken risers, cracked nozzles, or heads tilted at the wrong angle spray water onto sidewalks, driveways, or miss target areas entirely.

Solution: Adjust head positions, replace damaged components, and ensure proper spray arc and radius settings.

3. Low Water Pressure

Insufficient pressure prevents heads from reaching their designed spray distance. Common causes include mainline leaks, partially closed valves, pressure regulator failure, or too many heads on a single zone.

Solution: Check for leaks, test pressure at each zone, adjust regulators, and redesign zones with too many heads.

4. Mismatched Sprinkler Head Types

Mixing rotors, spray heads, and different nozzle types on the same zone creates uneven precipitation rates. Some areas receive too much water while others don't get enough, even when all heads are working correctly.

Solution: Group heads with similar precipitation rates on the same zone, or adjust run times for each zone based on head type.

5. Valve or Zone Issues

Faulty valves, stuck diaphragms, or wiring problems prevent zones from opening fully. This reduces flow to all heads on that zone, creating widespread dry spots even when individual heads are clean and aligned.

Solution: Test and repair or replace malfunctioning valves, check wiring connections, and verify controller programming.

How to Test for Uneven Coverage

Perform a catch-cup test to measure distribution uniformity:

Place identical containers (tuna cans or rain gauges) in a grid pattern across your lawn
Run the zone for 15 minutes
Measure water depth in each container
Calculate the average and compare individual readings
Containers with significantly less water indicate coverage problems

Professional Repair vs. DIY

Simple fixes like cleaning heads or adjusting spray patterns are DIY-friendly. However, pressure problems, valve repairs, and system redesigns require professional expertise. Arizona Irrigation Repair LLC diagnoses coverage issues quickly and restores uniform watering to protect your landscape investment.

Why Choose Arizona Irrigation Repair?

29+ years of desert irrigation expertise
Comprehensive system diagnostics and catch-cup testing
Licensed, insured, and family-owned
Same-day service available throughout Phoenix Metro

Why Isn't My Sprinkler System Watering Evenly?