When your sprinkler system kicks on but half your lawn stays dry, you're looking at one of the most common problems we see in Houston yards. The system itself is working, the water is flowing, but coverage is spotty or completely missing in certain zones. This usually means something is wrong with the sprinkler heads, the water pressure, or how the system is laid out. The good news is that most of these issues are fixable without replacing the whole setup.
Check Your Sprinkler Head Adjustment
The first thing to inspect is the sprinkler heads themselves. Most spray heads and rotors have adjustment screws that control the direction and distance the water travels. Over time, people bump them with the mower, weather shifts them, or they just get turned the wrong way by accident.
Walk out to your yard while the system is running. Look at each head and see where the water is actually going. If a head is pointed at your house instead of your lawn, that's an obvious problem. The adjustment screw is usually on top of the head. You can turn it with your fingers or a flathead screwdriver to point the spray where you need it. For rotors, the arc adjustment lets you set how wide the spray pattern is. If a rotor is only throwing water 90 degrees when it should cover 180 degrees, your coverage shrinks fast.
Look for Clogged or Broken Heads
Dirt, sand, and debris get into sprinkler heads constantly in Houston. Our soil and water quality mean sediment buildup happens regularly. A partially clogged head will spray unevenly or shoot water in a weak stream that doesn't reach the far edge of the zone.
Pop off any head that looks suspicious and rinse it out with clean water. Sometimes you can clear the nozzle opening with your finger or a small brush. If the head is cracked or the nozzle is permanently damaged, you need to replace it. A single head replacement is cheap and takes ten minutes. Broken heads also waste water, so fixing them saves money on your water bill.
Test Your Water Pressure
Low water pressure is a silent coverage killer. If your system doesn't have enough PSI, the water won't travel as far, and distant parts of your lawn get less coverage or none at all. Houston's water supply pressure varies by neighborhood and time of day. Morning watering often has better pressure than evening watering when demand peaks.
You can check pressure with an inexpensive gauge from any hardware store. Screw it onto a hose bib near your main valve. Most spray heads work best at 40 to 60 PSI. Rotors need 40 to 80 PSI depending on the model. If your pressure is consistently below 40 PSI, you may need a pressure regulator or a booster pump. We can help you figure out which one makes sense for your system.
Examine Your Zone Layout and Head Spacing
Sometimes the problem is how the original system was designed. If sprinkler heads are spaced too far apart, you get dry strips between them. Houston yards vary in size and shape, and a system installed years ago might not match your current landscape.
Walk the perimeter of each zone and measure the distance between heads. Most spray heads effectively cover a 15 to 20 foot radius. Rotors cover farther, usually 20 to 40 feet depending on the model and pressure. If your heads are 30 feet apart and you're using spray heads rated for 15 feet, you have gaps. Adding a head or two in the right spots fills those gaps. This is more work than adjusting existing heads, but it's a permanent fix.
Check for Leaks in Your Lines
A hidden leak in your underground lines steals water pressure from the rest of your system. If you notice wet spots in your yard that don't match your sprinkler head locations, or if your water bill jumped suddenly, you probably have a leak.
Some leaks are obvious, like water bubbling up or pooling in one spot. Others are harder to spot. If you suspect a leak, turn off your system and watch your water meter for 30 minutes. If it keeps running, you have a leak somewhere. Leaks are a bigger repair job because they involve digging and line replacement, but they affect your whole system's performance.
Seasonal Adjustment in Houston
Houston's heat and humidity mean your lawn needs different watering schedules in summer versus winter. Your sprinkler coverage might look fine in November but inadequate in July when evaporation is high and your grass is stressed. Consider adjusting your runtime and frequency with the seasons rather than assuming one setting works year-round.
If your system runs but doesn't cover your yard evenly, start with the simple fixes: adjust the heads, clear any clogs, and check your pressure. Most coverage problems come from those three issues. If you've done those and still have dry spots, JB Irrigation & Services can do a full system evaluation and tell you exactly what needs to change. Call us and we'll get your whole yard green again.
