Irrigation & Sprinklers: questions, answered with sources
Each answer cites the public sources it was checked against, with the date it checked them. Jobs that need a licensed pro in Virginia say so, and explain the job instead of teaching it.
Backflow Testing
4 answers
What is a backflow preventer, and how is it tested?
A backflow preventer is a one-way valve assembly that keeps water from your sprinklers, pool or other equipment from flowing backward into the drinking-water pipes. It is tested with a gauge by a certified tester at installation, after repairs, and at least once a year, and the result goes on a signed test report.
How much does backflow testing cost in Virginia?
There is no set Virginia price for a backflow test. Testers set their own rates, and Chesterfield County says it does not set testing rates or collect any revenue from these tests. The price depends on how many assemblies you have and any repair or re-test. Get two or three written quotes, and ask what the fee includes.
Does Virginia require annual backflow testing?
Yes. The Virginia Residential Code says backflow assemblies must be tested at installation, after repairs or relocation, and every year thereafter, and Fairfax and Chesterfield counties both enforce an annual test. Virginia's tester certification is voluntary under state law, but your locality can require a certified tester, so ask your building department or water utility.
Why did my backflow preventer fail its test?
Most failures come from an internal check valve or relief valve that no longer seals: debris on a rubber seat, worn parts, or freeze damage. Some come from installation problems. A failed assembly is usually repairable, but it needs a certified tester or plumber to repair or replace it, then pass a re-test before the report is accepted.
Drip Irrigation
5 answers
How do I set up drip irrigation for a garden?
Sketch the bed, then run a timer, filter and, if your pressure is high, a pressure regulator from the spigot to surface tubing. Use drip line along rows or one emitter per vegetable plant, flush the line, check for leaks and set short, frequent watering. Call a pro before tying into house plumbing or a sprinkler system.
How much does drip irrigation cost in Virginia?
No Virginia government source publishes a dated price for drip irrigation, so we do not quote one. Cost depends on the number of zones and emitters, how it connects to your plumbing, backflow and permit needs, digging and the controller. Get written, itemized quotes from licensed contractors and compare them line by line.
Should I hire someone to install drip irrigation?
Do it yourself if it is one bed or a few containers fed from a hose spigot. Hire a licensed contractor if the system will tie into house plumbing or a sprinkler system, needs trenching, covers several zones or needs backflow protection or a permit. Check the DPOR licence and get the scope in writing.
Why is my drip irrigation watering unevenly?
Uneven drip watering is usually clogged emitters, a dirty or missing filter, a leak upstream, or pressure that is wrong for the tubing. Run the zone, see where the wet spots stop, then clean the filter, clear weeds and blocked emitters, and check for leaks and a pressure regulator. Keep one emitter flow rating on each run.
How do I winterize drip irrigation?
Winterize drip irrigation before the first freeze: shut off the water, take the timer, filter and pressure regulator indoors, open the end caps and drain each run, and wrap any outdoor shutoff valve. In Virginia the average first freeze runs from October 10 in Blacksburg to October 27 in Danville, so start in early October.
Rain & Soil Sensors
1 answer
Smart Controllers
3 answers
How do I set up a smart sprinkler controller?
Swap the old timer for the smart controller with its plug-in power unplugged, matching each labeled valve wire to the same zone terminal. Join your Wi-Fi in the app, enter your address and describe each zone: plant, sprinkler type, soil and sun. Run every zone by hand, fix leaks and tilted heads first, and use short cycles where water runs off.
Are smart sprinkler controllers worth it?
Usually yes, for an in-ground system on a basic clock timer. The EPA says a WaterSense labeled controller can save an average home up to 15,000 gallons a year. They are not worth it if heads are broken or valves leak, so fix those first. Ask your water utility about rebates, and get three written bids if you hire.
Why is my smart sprinkler controller not running on schedule?
Most missed runs come from a paused schedule, a wrong date or time, a lost Wi-Fi or power connection, or a weather or moisture skip working as designed. Check the app's run history and skip reasons, confirm the clock, then run each zone by hand. If a zone will not start by hand, the cause is a valve or wiring, not the schedule.
Spring Startup
4 answers
How do I turn my sprinkler system back on in the spring?
Wait until the soil is frost-free about 12 inches down, check the backflow device and clear the heads, then open the main valve slowly to avoid water hammer. Run each zone by hand, watch for leaks, mist and stuck heads, check pressure is 45 to 75 psi, then set your spring schedule.
How much does a sprinkler spring startup cost in Virginia?
No Virginia government or manufacturer source publishes a dated price for a spring startup, so quote it by the job. The price follows the number of zones, what the visit includes, repairs found and whether the backflow test is bundled. Check whether your fall blowout already covered startup, and get written quotes.
Why are my sprinkler heads not popping up after winter?
Usually the head is buried in grass or debris, the stem is stuck or damaged, or the zone is not getting enough water. Make sure the ground has thawed and the main valve is open, clear around the head, then run the zone by hand. One dead head means replace it. A whole dead zone points to the valve.
What should I check on my sprinkler system every spring?
Check eight things: frost-free soil, the controller and its battery, the backflow device, debris around heads, cracked or worn parts, valves for leaks, a slow main-valve start, and pressure. Then run every zone by hand and watch for leaks, pooling and spray hitting the driveway. Have the backflow device tested yearly.
Sprinkler Installation
5 answers
What does installing an in-ground sprinkler system involve?
A licensed contractor designs zones, has utilities marked through Virginia 811, trenches and buries the pipe, ties into the water line through a backflow preventer, sets valves, heads and a controller, and has the backflow assembly tested. Localities require permits for the backflow device. Hire a licensed irrigation or plumbing contractor and get three written bids.
How much does a sprinkler system cost in Virginia?
There is no single Virginia price, and we found no official Virginia source with a dated installed cost. Price depends on zones, yard size, soil, backflow assembly, controller and permit. As of October 27, 2026, Chesterfield County lists its irrigation companion meter at $940. Get at least three itemized written bids from licensed contractors.
Do I need a permit or a backflow preventer for a lawn sprinkler system in Virginia?
Yes to the backflow preventer: the Virginia Residential Code requires one on a lawn irrigation supply. A permit and inspection for it are required by localities such as Prince William, Chesterfield and Fairfax counties, and Chesterfield and Fairfax want it tested annually by a certified tester. Ask your local building department for its permit and fee.
Why is my new sprinkler system not reaching parts of the lawn?
Most coverage gaps are spacing, aim or nozzle problems. Run each zone and flag the dry spots. Check that every head pops up straight, reaches the next head, is aimed at the lawn and has a clean nozzle, then measure with a catch-can test. If gaps remain, tell the installer in writing. Pooling water or a weak zone means a pro.
How long does an in-ground sprinkler system last?
No agency publishes a service life for a whole system, because parts age on different clocks. Freezing is the main threat to buried pipe, mowers break heads, and the backflow assembly must be tested yearly and overhauled about every five years. Winterize each fall, check zones each spring and keep the tests current.
Sprinkler Repair
5 answers
How do I replace a broken sprinkler head?
Turn off water to the zone, carefully dig around the head with hand tools, unscrew the old head, check the riser underneath, wrap the threads with Teflon tape and screw on a matching head. Flush the line before you refit the nozzle. If pipe is cracked or a valve will not shut off, call a licensed irrigation contractor.
How much does sprinkler repair cost in Virginia?
No Virginia government source publishes a dated price for sprinkler repair, so we do not quote one. Cost depends on what failed (a head, valve, buried pipe, wire or controller), how deep the digging goes, and whether a backflow test or permit is involved. Get at least three itemized written estimates from licensed contractors.
Should I repair my sprinkler system or replace it?
Repair it when the damage is local: heads, nozzles, a joint, a valve or a controller. Most parts can be swapped in place, and water-saving heads and nozzles fit existing fittings. Consider replacement when failures are spread across many zones or the layout no longer matches the yard. Get a repair bid and a replacement bid from licensed contractors, and compare.
Why won't one of my sprinkler zones turn on?
Test the zone by hand: run it from the controller, make sure the main water is open, then turn the solenoid on the valve to open it manually. If it sprays by hand, the fault is power, usually a broken wire or a bad solenoid. If not, the valve or the supply is blocked, and a pro should open it.
How do I keep sprinkler heads from breaking?
Keep heads from breaking by flagging them before mowing, trimming grass around each one so the stem rises freely, setting them level with the turf, replacing cracked parts early and keeping pressure in range. Rain Bird says most systems run best at 45-75 PSI. Open the main valve slowly each spring.
Winterization & Blowouts
5 answers
How do I winterize a sprinkler system?
Shut off the sprinkler mainline, set the controller to rain mode, then get the water out of the pipes: open the manual drain valves, let automatic drains open on their own, or blow the lines out with a compressor limited to 50 psi while wearing eye protection. Insulate an exposed shut-off valve, protect the backflow device from freezing as your water utility allows, and leave the device itself alone.
How much does a sprinkler blowout cost in Virginia?
A blowout is priced by the job, not at a flat rate: the price follows the number of zones, the access to the blowout fitting and any backflow device work. Get two or three written quotes that say what is included, and ask whether spring startup is bundled.
Should I hire someone to blow out my sprinkler lines?
Hire it out if you do not have a compressor that delivers 10 to 25 cubic feet per minute, if you cannot tell where the blowout fitting and drains are, or if the backflow device needs attention. Do it yourself only when you have the right compressor, a 50 psi regulator, eye protection and a system with simple zones.
Why did my sprinkler pipes crack over the winter?
Water left in the pipes, valves or backflow device froze and expanded, and that pressure split them. Buried lines are not safe: Richmond Public Utilities says most yards do not bury sprinkler lines deep enough to escape the cold. In spring, open the water slowly, run each zone, and look for pooling water to find the damage.
When should I winterize my sprinklers in Virginia?
Before the first freeze, which averages from about October 10 in Blacksburg to October 27 in Danville, with later dates toward the coast. In practice, aim to be finished in the first half of October in the mountains, by mid to late October in the Piedmont, and by late October to early November in the southeast, and move sooner if the forecast shows a night near 32 degrees.