Chasing Lawn Sprinkler Leaks

 Fixing easily corrected household water leaks can save homeowners more than 10 percent on their water bills. sprinkler21


 Unfortunately many of us require lawn sprinklers to have any kind of landscaping short of cactus, gravel and rocks. Having a lawn sprinkler system is kind of like garage door openers, once you have one its hard not to. Dragging hoses around the yard is a real pain and it becomes a challenge to keep things alive. Taking care of your sprinkler system will save you money,  reduce the opportunity to waste water and keep your plant material alive. With water restrictions  on the upswing,  more and more cities are assessing fines for violating the restrictions.  Check with your local municipality for restrictions regarding time of day, rain and freeze detection.  Adding a rain sensor to your system is a wise decision.   

Rain Sensor

Rain Sensor


Because sprinkler heads are not under pressure until the system is live,  it can be difficult to isolate the leaks. “Pop-ups”  are the most common spray heads found in  residential systems. Typically I find  pop-ups require more maintenance than the larger impulse or stream sprayers primarily due to the fact that pop-up sprayer use less water per head and the water orifices are smaller and they clog easily.  With pop-ups, it takes more heads per square foot to provide adequate coverage. The greater the distance between heads, the further the water has to spray.  To do this, the arc in the spray pattern has to be projected higher in the air.  As a result,  you lose up to 50% of the water in the air.  Up until the last year or so, we have seen little in the way of water miser type heads. These new type heads are designed to replace the pop-up with a miniature stream sprayer providing a coarse spray in lieu of a mist. This can help reduce water loss and your system may be retrofitted to use these type heads. However, it is important to match the right head for the system. When your system was designed,  it was all based on a certain water pressure, pipe size and GPM (gallon per minute) volume, so any changes need to take this into account otherwise you may end up over/under-watering. Not that a DIYer cant figure this out,  a good licenced irrigator can help you solve the problem. Also, take a look at this comparison study of nozzle types.   

Top 5 Reasons Why Water Sprinklers are Wasteful   

  • Poor design: System design that allows sprinklers to spray water across sidewalks or concrete cause water to be lost to evaporation and run off. 
  • Wrong watering times:  Running your water sprinklers in the middle of the day allows the water to evaporate before it has time to absorb in to the ground. 
  • Wrong water duration: Some believe short duration watering is a way to conserve water however, short shallow watering can cause turf and plants to experience stress because the shallow water can cause shallow roots.
  • Dirty nozzles: Even though sprinkler heads (should) have filters underneath the nozzles, they can still pass some particles in to the nozzle. Many times bad-sprinklerthese particles can be wedged in the spray nozzle causing it to mis-spray and not distribute water equally and efficiently throughout the spray pattern.
  • Lack of maintenance: Sprinkler heads take a lot of abuse from lawn mowers, string trimmers and edgers. Whether it be abuse,  leaky or bad sprinkler heads, all of these conditions can cause a lot of water to run down the sidewalk. 

Standard spray nozzles are approximately 50% efficient as the over-spray is lost in the air.  Loss and waste in a sprinkler system can be difficult to recognize without taking the time to exercise the system and inspect each sprinkler head while running.   

 Keeping your lawn sprinkler system in good working order is one of the easiest ways to get optimum performance from your system. Most all lawn sprinkler systems can be defined in two distinct parts:
  • Feeder or Pressure Lines: The side under pressure includes a cut off valve, double check valve (aka back flow prevention valve) and a valve for each zone and a lot of pipe. 
  • Distribution Lines or Zones: The system could include any number of  zones, this is all dependent on the size of the system. The zone has to be running to inspect it for leaks. Since the sprinklers are spraying water, finding leaks can be a bit more challenging.

Chasing Lawn Sprinkler Leaks   

Feeder or Pressure Line  Leaks:   

  1. Finding leaks in feeder/pressure lines is similar to the same process as found in the Chasing Water Leaks post. Turn off the main cut-off that will isolate the sprinkler system from the remaining water supply. If the flow meter stops proceed with the following steps.
  2. Locate each sprinkler valve in your system. If you are not sure how many valves are in your system, look at your Sprinkler Controller to identify how many sections or zones are in the system. Finding the sprinkler valve may be difficult as valves can be overgrown by grass or ground cover.  If you have the original installation drawing, it should identify the approximate locations of the valves. Before you hire a professional, try the methods described in Searching for Lawn Sprinkler Valves. Either way, once you find them, take note of their location for future use. 
  3. You may notice water residue around some sprinkler heads even when it should be dry, known as weeping, this could be a hint that the sprinkler valve is passing water when it should not be.
  4. Once the valves are located, they should be turned off, one at a time to determine if you have isolated the leak. Each valve has a manual cut off on the center top of the valve. Once you have isolated the leak to a specific zone, the problem will be resolved at the valve. (TIP: Sprinkler valve can be disassembled and cleaned without removing them from the system but the water must be shut off.) Most likely it just needs to be cleaned (that means taking it apart and removing any dirt or debris inside the housing),  but it could have been damaged during the winter months, if so, you may need to replace the valve. Read this tutorial for specific instructions on repairing a solenoid valve.

Distribution Lines or Zones: (Plan to get wet)   

  1. Run each section one at a time. Walk the zone looking for excess water accumulation around the head, the seal could be bad or the head loose causing a lot blown-sprinkler1of blow by. Try tightening the head, (yes, all this while the system is running). If none of this stops the excessive water, replacing the head and riser is the simplest solution. If the leak is around the stem or nozzle riser, you can take these head apart for cleaning. Perform this action with the water turned off. To avoid additional dirt in the system, its best to dig away the dirt from around the head, down to the connection otherwise dirty water will enter the lines. It’s important to remember to do your best job of keeping new dirt from entering the system as this will cause more blockage problems further down the pipe. TIP: Keep a couple of extra sprinkler heads around for spares and spare parts. Changing the head is lots less invasive and a 1 for 1 head swap out than trying to operate on the head in the dirt and water. You can also rebuild the removed head for future change-outs.
  2. If the head is not leaking inspect the pattern of the water spray. Different nozzles are designed with different patterns, so the spray could be limited by design to provide adequate coverage. There are too many nozzle patterns to discuss, but most importantly, look for a  nice clean even pattern. If you see breaks or weakness  in the pattern, the nozzle is probably dirty. Turn the zone off and unscrew the nozzle. There will be a  filter in the riser. Clean the dirt out of it. Also inspect the nozzle itself for very small pebble grit lodged in the sprayer. Use a toothpick or very small screwdriver to remove these particles. The last item may require 2 people. Run the zone without the nozzle installed, this will blow-out any dirt particles that are below the filter. Tell your partner to turn the water off and grab the riser before it stops releasing water. This will keep  dirt from re-entering the system. Re-install the filter and nozzle. Perform this same inspection with each sprinkler zone.   
  3. If necessary, (while the zone is running) adjust any partial pattern sprayers that may be near sidewalks or driveways to keep the water spraying on the grass. If you have parkway sprinklers that  are designed to water across a sidewalk (bad design)  to water grass or plants, you may be stuck with leaving it alone since cutting it back may cause an area to be dry.

Key Inspection Points and Action Items:   

  1. Look at your water meter for any slow leak that may be caused by your sprinkler system. Isolate the sprinkler valves to determine where the leak is.
  2. Run each zone, inspect each head for leaks, also look for a good pattern and good coverage. Cleaning the heads may be required.  
  3. Adjust the sprinkler heads as necessary to minimize water over-spray on no-porous surfaces (sidewalks and streets).
  4. Adjust your water cycles to match the season.

18 Responses to Chasing Lawn Sprinkler Leaks

  1. James says:

    This is why it’s important to have your system blown out properly in the off-season, and turned on by professional when spring rolls around. If your irrigation/lawn sprinkler company doesn’t give your system a thorough once-over when turning it on (checking for leaks, bad heads, wasteful run-off/overspraying) then they aren’t doing their job!

    Great article, by the way!


  2. homeownerbob says:

    Thanks James, In my part of the country, shutting the system down is still an option as many times we have to continue to water throughout the year. However, by doing so, we run the risk of quick cold spells that may put our system at risk. I like to check the systems at the begining and end of the primary watering season for that very reason. Thanks for your comments. HomeownerBOB

  3. […] to use automatic lawn sprinklers to do our watering.   Hopefully you have read my post on Chasing Lawn Sprinkler Leaks.  This is a good start, but it just barely touches the subject of efficiency. Besides fixing […]

  4. […] Efficiency Part II, Lawn Sprinkler Efficiency Part I ,  Searching for Lawn Sprinkler Valves, Chasing Lawn Sprinkler Leaks Possibly related posts: (automatically generated)Water Saving Tips from Richard […]

  5. […] Lawn Sprinklers: Exercise the system. Look for excessive water traveling down the driveway or sidewalks. Inspect the sprinkler heads, look for blow-by and odd spray patterns. Replace or repair the heads. If you need more help on this item, click the “lawn sprinklers” tab to see multiple subjects on locating lost heads, valves as well as tune-up recommendations. […]

  6. […] spray patterns, missing heads, pooling water and brown spots.  Replace or repair the heads. Chasing Lawn Sprinkler Leaks is the first of the series and covers the inspection, leak detection, repairs and tips in more […]

  7. […] Lawn Sprinklers: Exercise the system. Look for excessive water traveling down the driveway or sidewalks. Inspect the sprinkler heads, look for blow-by and odd spray patterns. Replace or repair the heads. If you need more help on this item, click the “lawn sprinklers” tab to see multiple subjects on locating lost heads, valves as well as tune-up recommendations. […]

  8. […] odd spray patterns, missing heads, pooling water and brown spots.  Replace or repair the heads. Chasing Lawn Sprinkler Leaks is the first of the series and covers the inspection, leak detection, repairs and tips in more […]

  9. R says:

    Just an FYI I work the water company in a municpality and customers are not allowed to touch the meter including opening the lid to look at the meter. If a customer causes damage to the meter, which is actually city property not the home owner’s, they are charged for the repair which is around $300.00 or more depending on the damage.

    • homeownerbob says:

      Thanks for your insight. Do you know this to be a local ordinance for your community or nationally recognized in something like an IBC or UBC? Is it clearly stated where all the homeowners fully understand the consequences? In my experience I have found local ordinance, as well as its interpretation to be as unpredictable as the weather, and are in place to use when necessary.
      From my research I have found most water departments highly appreciate any homeowner that is taking a proactive approach to water leaks and conservation. I can easily change my wording to check local ordinance before performing any activity associated with the water meter. Thanks for your comments

  10. Mike M says:

    Yeah, but how do you locate a leak AFTER the valve. pressure is only on it for 10 minutes a day, not long enough to cause green areas.I have a run (unknown route) of over 50 ft from the region valve to the the first head (7 heads)(I didn’t install it originally) through multiple tree roots. The pressure at the heads of the station have noticeably dropped. How does one find where in the region the cracked line is?

    • homeownerbob says:

      Mike, this is where it gets fun. I cover a bit of this isolation in the article . “Finding the Lost Sprinkler Head”. Basically you have to force the leak to show itself. If you have identified all the known heads on that circuit, you need to turn them off using the screw on top each head. If you cant turn them off. You may have to cap them. Meaning, 1)unscrew the head and replace it with a threaded riser with a threaded PVC cap. Adjust your timer to let it run longer than 10 minutes, more like 30. It should show up that way. BOB

  11. Eirich Marsha says:

    we had our new driveway poured last February. This year when we turned our sprinkler system we had water run off at the end of our driveway and into the street. We are wondering if the leak is underneath all of the new concrete or if there is a waterleak detection device that we can use. We hope to NOT tear up our new driveway to find the leak and fix it. Marsha

    • homeownerbob says:

      Tearing up the driveway would be a last resort. You have lots of options before you resort to that. This is not a quick/easy DIY solution, and you might want to employ a sprinkler repairman that is willing to spend some time on it. There are some leak detection devices out there, but it may lack the accuracy you need in this application. If the driveway people did the damage, you might be able to get some compensation for the fix. Digging around may be your best path. Here is a basic path to isolating the problem.
      • I assume there was an old driveway that was taken out in the same place where the new one was put? Or a new driveway was installed where grass was, as well as sprinklers.
      o Either way, there is a good chance a damaged pipe or old head is causing the problem.
      o I also am assuming the leak only occurs when the sprinkler is running?
      • The hardest thing to do is to isolate the problem.
      o If you have an original sprinkler drawing that shows where pipes and heads were, that can help.
      o You are going to have to find the pipe that is bringing water under the driveway.
       To do that, find the heads that are closest to the driveway (coming from the water source), dig up around the heads to see if the pipe continues toward the driveway.
       Dig again at the driveway to confirm the pipe is going under the driveway (there could be multiple pipes going under the driveway, so don’t stop just cause you found one from one head).
      • If so, you will have to cut it open and cap it. If the water stops, you have found it. (if you have multiple pipes, you will have to do them all, one at a time)
      • Once you do this, you have probably disconnected some other heads that you still want to use. Depending on the number of heads you have isolated, will define your next step.
      • You will have to find the pipe that is feeding those isolated heads from the other side of the driveway. (This is where it gets real ugly) Assuming the driveway is less than 10-12 ft wide, you can use water pressure to bore a new hole under the driveway for a new pipe. Essentially, you use a piece of PVC with a pressure nozzle on the tip to drive it under the driveway all the way to the other side. If there is a shorter way to get there, do it.
      • You could also consider creating a new water sections for the heads you lost, but you will have to identify where you can get your new water source (tap into it for a new solenoid valve) and also it will require wiring to connect back to the controller.

      I went thought this pretty quick and consider this fairly drastic and extensive, but it beats ripping up the driveway.

      Good Luck,

      • richard burley says:

        bob I have a question this month my bill jump 10’ooo gal. I shut
        of the system in yard. they check meter etc everything ok. they say the water went through the meter. my question is if the crack in the pip is downward the water would never be notice on the surfice. and maybe even cause sink holes. if the water flow is not fix. im trying to find that leak. if I turned each zone on separate would the meter go faster with the more water flow. which would indicate a leak.

      • homeownerbob says:

        It may be difficult to recognize the difference in flow from one section to the next, but it may be worth a try since my method will take a bit longer. Here is what I would do:
        1. Identify each sprinkler head by section, do one section at a time.
        2. Turn off the nozzle for all the sprinkler heads in that section. There should be a little screw in the top of each nozzle. It is typically the opposite of what is normal as you will turn the screw counter clock wise
        3. Turn the section back on and watch the meter. It will probably still move a little (as the nozzles may not totally seal off the water)
        4. Do this for every section.
        5. If you find the water meter still moving rapidly, go look for the leak around that section of heads.
        6. I have found

        Good Luck, BOB

  12. jessie says:

    is there some gadget that will tell me if there is a leak? Some smart people that know yards and engineering should get busy and make us something to take care of our needs…

    • homeownerbob says:

      Yes there are various leak sensors out on the market. However, they are not very cheap (+$100). I know what you are saying though as in some cases, you don’t know until you get the water bill. Even checking mine before and during each watering season, I have still missed a leak.


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