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How to Detect Irrigation System Leaks

Green grass lawn - How to Detect Irrigation System Leaks

An irrigation system can run trouble-free for many years, especially if it is well-maintained. But at some point, it may start leaking, and an unnoticed or unrepaired a leak will waste water and cost you money.

Fortunately, there are actions you can take to discover leaks, even those below ground.

Leak Warning Signs

  1. Bright green patch of grass. A small bright green patch of grass is one of the most common signs of leaks that we see. Because we are in such a dry climate, the leak continuously waters the small area making it a much brighter green color than the area surrounding it.
  2. Unexplained spike in your water bill. If your water consumption inside the home hasn’t changed, make sure your controller is programmed correctly and not overwatering. The next step is to start looking for leaks in your irrigation system.
  3. Above ground backflow prevention assembly (BPA) continuously drips, or there’s a puddle of water around it. For underground BPAs, water in the box could indicate a leak.
  4. Wet spots. On a sunny day there’s a muddy or wet patch on your lawn, and the other sections are dry. If the wet patch doesn’t dry up eventually, it’s probably a leak.
  5. Soggy ground. The ground feels squishy whenever you walk on wet grass areas.
  6. Pools of water. Water should soak into the ground, but if you see it pooling and not being absorbed, it could be a leak.
  7. Uneven ground, sinkholes, or erosion. Ground that’s oversaturated will be lower than the rest of the lawn. Sinkholes can also develop. It may even appear as if an animal has been digging in the area.
  8. Mushrooms growing in patches. It’s uncommon to see mushrooms growing on a lawn unless a section is constantly wet. You’ll also find mushrooms growing where there’s a pipe leak near trees. The tree roots grow around the pipe, crushing and then cracking it.
  9. Your patio, sidewalk, or driveway are always wet. Unless it rains constantly or your nearby sprinklers are misaligned, there’s no reason for these surfaces to remain wet unless there’s a leak.
  10. Water in valve boxes could be rainwater, or a leaking pipe or valve. If just the area below the valve is damp, check the valve for leaks.
  11. Dry or brown grass areas. A pipe leak in a zone reduces the water pressure and causes low coverage or strange sprinkler patterning.
  12. Water leaking from the lowest zone sprinklers when the system is turned off. One of the causes for this is a leaking zone valve. A common sign of a leaking valve is algae or moss growing on a sidewalk near the sprinklers because of the constant water flow. Another indication is puddles of water around the sprinklers that never dry out.

Water that leaks from the lowest sprinklers, then eventually stops, is called “low head drainage”. It can be fixed by installing a check valve on the sprinklers or replacing them with sprinklers that have built-in check valves.

It’s possible to have both problems, so check for a leaking valve first.

Signs of Leaks When a Zone is Turned on

Manually turn on each zone one at a time, and watch for the following leak indicators:

  1. Dirty water from the sprinklers. Soil can enter leaking pipes that are broken or cracked, mixing in with the water streaming from sprinklers.
  2. Water pressure has changed. If the coverage between sprinklers is no longer head-to-head (100% overlap), a leak may be affecting the water pressure. The leak is probably close to the beginning of the zone if the entire zone coverage is obviously lower. If the coverage only gets lower closer toward the end of the zone, that’s where you’ll find the leak.
  3. Water bubbling up between sprinkler heads. Water from a broken lateral pipe has pushed out the soil above it and is rising to the surface.
  4. Pop-up sprinklers not completely extending and shooting or spraying little water. Sprinklers won’t pop up or stream fully if a leak in a pipe is lowering the water pressure.
  5. Water geysers from sprinklers. Sprinkler head is broken or completely missing.
  6. Pop-up sprinklers leaking. Water spurting from the base of the sprinkler’s extended riser indicates a bad seal. Replace it and replace the sprinkler if the riser is scratched.

If the leak is from the top of the sprinkler, make sure the cap is screwed on tightly.

  1. Spurts or pools of water at the base of sprinklers. These could be caused by a broken fitting connecting the sprinkler to the underground riser, or the riser to the lateral line. Also, the lateral pipe could be leaking, or the body of the sprinkler is ruptured.

Drip System

Visually inspect your drip system for the following indications of leaks or cuts:

  • Areas are extra wet and green. 
  • Wet spots around tubing where there are no emitters.
  • Pressure drop and/or flow increase.
  • Hissing sounds from leaking emitter holes facing downward.
  • Small geysers from leaking emitter holes facing upward.

Leak Detection Tools

If you can’t find an underground leak in your irrigation system despite your best efforts, leak detection tools are available as a last resort. They focus on the sounds leaks make, such as hissing, gurgling, or bubbling.

Sometimes you can hear these sounds if the sound is loud enough. But if not, the equipment listed below will give an approximate location so you’ll know the general area where to start digging. However, these leak detection tools are expensive and complicated to operate, and so are used mainly by irrigation professionals.

These leak detection tools include:

  • Electro-Acoustic testing kit. This kit includes a water leak microphone, a reader/logger, and headphones.
  • Water leak microphone. It’s a rod or probe you pass over the ground or insert in spots that will magnify the sound of water rushing through the pipe (or the sound of the pipe vibrating). The leak will be around the area where the sound is the most intense.
  • Leak Noise Logger. This hand-held reader/logger is attached to the microphone probe and records the intensity of the sounds the microphone is picking up. The logger’s digital readout will help you determine the direction where the sound is becoming louder.
  • Headphones. These help you block out other sounds and focus on the information from the leak detection probe.

Call the licensed irrigators at Smart Earth Sprinklers at 512-694-1147 or contact us online for your sprinkler system inspection, repair, and maintenance needs.

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