It’s early May 2026 in Utah, and irrigation system startup season is here. Your neighbors are already running their sprinklers, and you’re tempted to flip that valve and get your system going. But start too early, and you risk freeze damage that’ll cost you hundreds in repairs.
The process doesn’t have to be hard. There are a few Utah-specific things that make the difference between a smooth start and a basement full of water. We’re talking about timing around our unpredictable spring weather, dealing with secondary water systems, and making sure your backflow preventer is up to code.
While you’re tackling spring outdoor tasks, it’s also a good time to check your sump pump before Utah’s spring thaw. In this guide, we’ll walk through the eight steps for a successful irrigation system startup. You’ll know exactly when to turn on your sprinkler system this spring, how to avoid water hammer damage, and when it makes sense to call in a professional.
If you run into plumbing issues during startup � like a leaking backflow preventer, pressure problems, or underground leaks � call us at (801) 997-1617. We handle the plumbing side across the Wasatch Front.
When to Turn on Your Sprinkler System in Utah
Ask any longtime Utah homeowner when to fire up the sprinklers, and you’ll hear the same answer: Mother’s Day. It keeps you from starting too early and damaging your system with a late-season freeze.
The data backs this up. Salt Lake City is 90% frost-free by May 24, and about 50% frost-free by May 8. If you start before early May, you’re taking a gamble.
The best signal isn’t a calendar date, though. It’s steady daytime temps in the 60 to 70 degree range and grass that’s actively growing.
Stick a screwdriver into your lawn. If it slides in easily to about six inches, the ground has enough moisture. No need to water yet.
If you’re on secondary water, your city typically charges the system in mid to late April. But even after they turn it on, wait at least two weeks before you start using it.
Step 1: Check Your Irrigation System for Winter Damage
The first phase of any irrigation system startup is to check your irrigation system for damage. Before you put any water in the pipes, walk your property and check for problems.
This sprinkler startup Utah process begins with a thorough damage check. Utah winters are hard on these systems. Freeze-thaw cycles crack pipes, split valve boxes, and damage backflow preventers. If you’re checking your irrigation system this spring, it’s a good idea to inspect your outdoor faucets for freeze damage at the same time � the same freeze-thaw cycles affect both systems.
Pop open your valve box lids and look inside. Standing water in a valve box is a red flag � it usually means something cracked or broke over the winter.
Your backflow preventer � the brass or bronze device that sits above ground, usually near your house � should be next. Look for cracks, leaks, or any parts that look displaced or bent.
As you walk the yard, watch for surface wet spots or depressions. These can signal underground leaks. Sprinkler heads need inspection too � you’re looking for visible cracks, missing heads, or heavy mineral buildup.
That mineral buildup is Utah’s hard water doing its thing. Calcium and limescale clog sprinkler heads over the winter � the same hard water damage that affects your indoor plumbing. Spring startup is the perfect time to clean that stuff off. If you’re tackling spring plumbing maintenance, check out our complete spring plumbing inspection checklist to catch issues across your entire system.
If you see major issues � a cracked backflow preventer, flooding valve boxes, or obvious underground leaks � don’t turn on the water yet. Call a licensed plumber to check the damage.
Step 2: Prep Your Irrigation Controller
Your controller is the brain of the system. Before you turn on the water, make sure it’s working. Check the battery if your controller has one � many systems have a backup battery that keeps the programming during power outages.
Check the display. If it’s blank, flickering, or showing error codes, you might have a bigger issue. Test the outlet or breaker to make sure the unit is getting power.
Don’t program your watering schedule just yet. Set the controller to manual or off mode for now. You’ll need to manually test each zone during startup.
Utah Secondary Water Systems: What You Need to Know
If you live in certain Utah communities, your system might be fed by secondary water � also called pressurized irrigation. This is a completely separate water system from your drinking water, designed specifically for outdoor watering.
Your city typically turns on the system in mid to late April, but you shouldn’t start using it right away. Wait at least two weeks after the city turns it on. The system needs time to settle, work out air pockets, and reach proper pressure.
Step 3: Slowly Fill the Pipes (Critical Step)
This is the most critical step of the irrigation system startup process. If you open the main valve too fast, you create something called water hammer � a pressure surge that can crack pipes, blow out fittings, and damage valves.
The pressure spike can exceed 100 PSI, which is more than enough to destroy PVC pipe joints that have been sitting dormant all winter.
Find your main irrigation shutoff valve. It’s usually in a valve box near where the irrigation line branches off from your main water supply or secondary water connection.
Before you touch the main valve, open the bleeder valves on your backflow preventer. These are small valves � usually two of them � that let air escape from the system.
Now, very slowly turn the main valve. We’re talking a quarter turn, then wait 30 seconds. Another quarter turn, wait 30 seconds.
Keep going until the valve is fully open. The entire process should take at least two to three minutes.
While you’re doing this, listen. You should hear water flowing through the pipes. If you hear loud rushing, hissing, or gurgling, that’s a sign of a leak somewhere.
Once the system is fully filled, close the bleeder valves on your backflow preventer. You should see a steady stream of water come out of them before you close them.
Step 4: Test Each Zone and Look for Problems
Now that your irrigation system startup is underway and pressurized, it’s time to test each zone. Head to your controller and manually turn on the first zone. Let it run for three to five minutes while you walk that section of the yard.
First, do all the sprinkler heads pop up? If a head won’t pop up, it’s usually mineral buildup from Utah’s hard water or freeze damage to the internal part.
Watch the spray pattern. Heads should spray in a steady arc without misting, sputtering, or shooting water straight up. If the pattern looks off, the nozzle is probably clogged.
Watch for geysers or puddles that form quickly. A geyser means a broken pipe underground.
Test every zone this way. It takes time, but you’ll catch problems now instead of discovering them mid-summer when your lawn is already dying.
If you find major leaks, pressure problems, or multiple zones that won’t turn on, that’s a sign of a deeper issue. At that point, contact Ninja for help.
Step 5: Schedule Your Annual Backflow Preventer Test
If your system connects to culinary water, you’re legally required to have your backflow preventer tested every year. It’s not optional.
Utah Code 19-4-112 requires backflow prevention on all systems tied to drinking water supplies and mandates annual testing by a state-certified tester. The device prevents dirty water from your system from flowing backward into the public water supply.
Cities can fine you for non-compliance, and in some cases, they’ll shut off your water until you provide proof of testing. Testing typically costs between $50 and $100.
If your backflow preventer is cracked, leaking, or failing the test, it needs to be repaired or replaced. That’s a job for a licensed plumber.
Step 6: Program Your Watering Schedule (Conservatively)
After testing, the final phase of irrigation system startup is programming your schedule. Start low. Your grass doesn’t need much water until temperatures are steadily in the 70s.
The best resource for Utah homeowners is the Utah Division of Water Resources Weekly Watering Guide. They publish updated recommendations every Friday, telling you exactly how much to water based on current weather and soil moisture.
For early May, a typical schedule might be twice per week, 10 to 15 minutes per zone. As temperatures climb into summer, you’ll increase the frequency and duration.
Use that screwdriver test again: push a screwdriver into your lawn. If it goes in easily to six inches, you have enough soil moisture. Don’t water.
Common Irrigation System Startup Problems and How to Fix Them
Even during a careful irrigation system startup, you’ll hit issues. Here are the most common irrigation system startup problems we see in Utah.
Heads won’t pop up. This is usually mineral buildup or freeze damage. Pull the head, clean the barrel and nozzle, and check for cracks.
A zone won’t turn on. If nothing happens when you turn on a zone, the problem is almost always the valve. The rubber seal might have failed, or the solenoid coil that opens the valve could be burnt out.
Pooling water or a geyser. This means a cracked pipe or blown fitting underground. You’ll need to dig, cut out the damaged section, and splice in new pipe.
Low pressure across all zones. Check that the main valve is fully open. If it is, you might have a pressure regulator failure or a partially clogged backflow preventer.
One zone stays on all the time. The valve is stuck open. This usually means debris is caught in the valve or the rubber seal has torn.
When to Call a Professional
Most homeowners can handle basic irrigation system startup. Cleaning heads, adjusting spray patterns, programming the controller � all DIY-friendly if you take your time and follow the steps.
But there are clear boundaries where professional help makes sense. Backflow preventer testing is one � it’s required by law, and you need a certified tester.
Underground leak repairs, especially on main lines or deep breaks, are another. Digging, pipe sizing, proper fittings, and pressure testing need experience and the right tools.
At Ninja, we handle the plumbing side of these systems. That means backflow preventer installation and testing, leak repairs, pressure regulation, and supply line work. We’re Utah state licensed with 20 years of experience, and we guarantee a 120-minute emergency response if something goes badly wrong.
If you need help getting your system up and running � or if you’ve found damage during your inspection � give us a call. We’re happy to help.
Frequently Asked Questions
When should I turn on my sprinklers in Utah?
Wait until at least May 1 for the Wasatch Front, and ideally until Mother’s Day. The safest bet is waiting for steady daytime temps of 60 to 70 degrees and grass that’s actively growing.
How do I know if my irrigation system was damaged over winter?
Check for standing water in valve boxes, cracks or leaks in your backflow preventer, surface wet spots, and sprinkler heads that won’t pop up or have visible damage.
What is a backflow preventer and do I need to test it?
A backflow preventer stops irrigation water from flowing backward into your home’s drinking water supply. Utah Code 19-4-112 requires one on every system connected to culinary water, and it must be tested annually by a state-certified tester.
What is secondary water in Utah?
Secondary water is a pressurized irrigation-only water system that’s separate from your drinking water. It’s common in cities like Lehi, Saratoga Springs, Eagle Mountain, and Kaysville.
Can I turn on my sprinkler system myself or should I hire a professional?
Basic startup is DIY-friendly if you follow the slow pressurization steps and carefully test each zone. But you must hire a certified tester for backflow preventer testing � it’s required by law.
Final Thoughts
A proper irrigation system startup in Utah comes down to three things: timing it right, filling the pipes slowly, and testing thoroughly. Wait until the risk of frost has passed, take your time bringing the system up to pressure, and walk every zone looking for winter damage.
Utah throws a few unique challenges into the mix � unpredictable late-season frosts, secondary water systems, hard water mineral buildup, and mandatory backflow testing. And if you’re also switching your HVAC from heat to AC this spring, that’s another seasonal task worth doing right. But once you know what you’re dealing with, the process is straightforward.
If you run into plumbing issues during startup, we’re here to help. Backflow preventer repairs, leak diagnostics, valve work, and pressure troubleshooting are all things we handle every spring across the Wasatch Front.
Call us at (801) 997-1617 � we’re available 24/7, and the $49 dispatch fee during business hours is waived if you go ahead with the repair. After hours and weekends, the dispatch fee is $149 ($99 if you’re on our Home Health Plan).
Need help? Learn more about our plumbing services or call us at (801) 997-1617.
