How to locate underground water leak?

   / How to locate underground water leak? #1  

njrqs

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Queensland, Australia
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Kubota L1-20 DT
Recall reading about this a while back but my searching has drawn a blank.....

Been noticing a large green patch in the front yard but had put it down to run-off from a dripper irrigated garden.

Well we have had 10" of rain and the rest of the yard has dried out but this areas is now a BOG !

Check water meter and sure enough it is ticking over so I have a leak to find.

Dug around a bit but there was so much mud and water in the holes it was hard going.

Any ideas where to start looking?

Do plumbers have any technology to help find these leaks.

It is a 1" poly line and is in a trench with the phone and power so that will make things interesting /forums/images/graemlins/confused.gif
 
   / How to locate underground water leak? #2  
Neil:
Perhaps try digging down beside the wet spot but on the uphill side. This way you can dig in dry dirt and locate the lines. Then just keep following the lines into the bog. If the lines are deep take precautions that the trench does not cave in.
Egon
 
   / How to locate underground water leak? #3  
With the complications of the electric, phone and unknown location on the leak, it may be easier to simply run a new line. If you do, make sure you use heavy duty poly, (160 PSI vs 80 PSI).

I always run my 1" poly water lines in rigid 4" ADS pipe. Around here water lines must be at least 5' deep to get below the frost line, and the expense is the trench, not the ADS. The ADS is insurance against the poly getting pinched or the wire getting cut by backfill. My lines are 200 - 800 ' long, if I ever had a problem I could pull a new line by digging a single hole at the well head.
 
   / How to locate underground water leak? #4  
Neil,

I had a similar problem and was able to isolate the leak to somewhere in about 75 feet of a 600 foot line. I took my best guess and dug a trench perpendicular and across the line at about 1/2 way. I bailed the water until I could figure out which side of the trench was the leak. This took quite a while because the downstream side drained back into the trench. I repeated this two more times. The third attempt was dead on the leak. I fixed the leak by adding 4 elbows to allow insertion into the line. Good Luck.
 
   / How to locate underground water leak? #5  
Hi Neil, if you check with the local water dept, they should have a set of microphones made especially for finding leaks. Just place them on the ground, and as you move them along the line, you can hear the leak as you get closer to it. It's what we use up here, especially in the winter.

If this isn't available, and if the line isn't too deep, and if you have a large enough leak, you might be able to hear it at night when there isn't much noise. Since you'll have to be on your hands and knees, with your ear to the ground, make sure the neighbors know what you're doing. Otherwise, the nice men in white coats might show up looking to give you a ride. /forums/images/graemlins/grin.gif

Words of wisdom, If you re-do the line, then make sure the main line is encased in a second line. Easy to just pull it out after. A one piece line is preferrable to any joints. If you have to have joints, make sure the clamps are taped down so that they don't interfere with removal. Also, the water should be in a seperate trench, a couple of feet to the side and at least a foot (35cm) lower. A four inch (10cm) outer casing for a 1 in (2.5cm) line is recommended. Good luck.
 
   / How to locate underground water leak? #6  
Do you have a mechanic's stethoscope? If so, I'd use it in the manner Mike Dumond recommended; works pretty well.
 
   / How to locate underground water leak? #7  
Use an air compressor. Since you say there is a bog in the area you should be able to minimize the location you need to inspect by replacing the water in the line with compressed air.
Put as much pressure on the line as water pressure, and look for bubbles rising in the swamp. Air will not migrate underground the way water does, so you should find it fairly easy.
 
   / How to locate underground water leak? #8  
I saw an article in Farmshow on how to take card board tube and a dixie cup to make leak detector. I thought it was bull but had to try it. It works good. Go to farmshow.com and look at last years online articles thes about five per list it is shown there.
 
   / How to locate underground water leak? #9  
You might try a heat gun. The kind that is used by fire departments and utilties. Just run the gun along the ground where you believe the leak to be, and look for a cold spot. Typically, these guns are used to seek heat, but they will also detect an area that is colder. I would expect that water leaking from the pipe would be colder than the soil. (I hope).

Steve
 
   / How to locate underground water leak?
  • Thread Starter
#10  
Geez, what is it about this site that I can post before bed and in the morning I have a mere 7 replies /forums/images/graemlins/tongue.gif

Having covered myself in mud yesterday arvo and sleeping on the problem I now know the solution....

Call a plumber !!

I'll pay for it I know but HE can slop around in the mud and play with the LIVE WIRES in the trench !!!

He says they have no magic detector so there will be a bit of digging I say.

Oh well, I work here at home and I can earn more per hour on my job than I pay him so the numbers say to cal lhim !!

Thanks guys for your help as usual.

Will be interesting to see what the problem is. Poly should be fine so I dunno why it is leaking?

Cheers
 
 
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