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.
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 these 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.
- 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:
- 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.
- 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.
- 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.
- 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)
- 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 of 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.
- 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.
- 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:
- 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.
- Run each zone, inspect each head for leaks, also look for a good pattern and good coverage. Cleaning the heads may be required.
- Adjust the sprinkler heads as necessary to minimize water over-spray on no-porous surfaces (sidewalks and streets).
- Adjust your water cycles to match the season.