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Missing Backflow Preventer/Main shutoff Valve for Lawn Irrigation System

Missing Backflow Preventer/Main shutoff Valve for Lawn Irrigation System

Old 02-11-18, 10:06 AM
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Angry Missing Backflow Preventer/Main shutoff Valve for Lawn Irrigation System

I noticed my water bill has been about 4 times higher that the same time last year (don't run sprinklers in winter). I checked the water meter and timed it for an hour. It showed 12 gallons used even with nothing on using water in the home. I checked all the toilets and they operate normally. I assumed it to be a leak in a sprinkler line. I have had leaks in the past and they were leaky valves and one burst underground pipe, all fixed by professionals with no issues reported to me. The sprinkler was installed when the home was built in Sept 2008.

So I called a reputable local sprinkler repairman and he comes out. He cannot find any evidence of a leak (mud, extra green grass etc.) I should note that my small residential lot is pretty much a solid piece of shale/rock. I remember watching the sprinkler being installed and they had to use jack hammers to trench. Same for installation of the trees.

This repairman also says he cannot find the back flow preventer and master control valve so he can at least shut the sprinkler system down until we can find the leak. I see my neighbors house and the valve is right up front in a clearly visible box. Mine is nowhere to be found.

I thought I might be able to trace one of the supply lines from a valve back to the main water source but after several hours I gave up. Just too much rock to get through.

I called the city out to investigate and they said there was also supposed to be a customer shut off valve on the house side of the water meter by which you can shut off water to the house....they were not able to locate that either.

Pretty open to any suggestions as I'm at my wits end.

thanks in advance,

Old 02-11-18, 10:24 AM
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There isn't much we can help you with. You need to locate where the sprinkler system connects to the city water. It's usually near the meter. It may be underground there.
Old 02-11-18, 01:36 PM
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It sounds like you have a leak somewhere. It might be in the irrigation system, the line to the house or something in the house. First I would carefully check out the toilets and make sure they are not slowly leaking before moving on to looking for a leaking underground pipe.
Old 02-11-18, 01:39 PM
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Look for a pipe T ed off of pipe from meter.
Old 02-13-18, 08:21 AM
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How were the prior repairs made....if the main water supply was not shut off ?

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