Sprinkler system underground leak help

[Dave FL]

Yep, got a leak somewhere. Did the timing thing with the water meter and found the three largest zones use most of the water.

My Problem: water bill came to $400.00 one month and $500.00 the next month. Stopped using the sprinklers and dropped to $50 - $60/Mo. My Guess: underground sprinkler leak My Question: What is the easiest way to check the lines for a leak? My Answer (up for review): Take out the sprinkler heads in each zone and cap off the line, run the sprinkler water and see if meter turns.

Need help to see if this is the best way to check the lines, or will a divining rod be better? Any comments would be greatly appreciated.

Dave FL

[Scott Hildenbrand]

Find the swamp in the yard caused by the thousands of gallons of water your system seems to be wasting.

Beyond that, capping all the heads and running the whole system to locate wet spots in the yard is about the only thing you can do.

But eesh, with that much water you'd think the problem area would be soaked enough to sink into when walked on.

[Dave FL]

Haven't noticed any swamps or really wet areas around the sprinkler heads

That was my thought too.

I agree, I also plan on getting rid of this St. Augustine grass & replace with Bahia. Dave FL

[Scott Hildenbrand]

What's the soil like in your area?

Swampy area don't need to be near any heads. They could be anywhere the line could break. But if your soil drains well then it's all together possible that it's draining off.

But at that much usage, wow.

ID where your lines run from start to end so that you can check the whole route as it's not just about the heads. When you cap everything and run it for a while, walk the line and see if you can pinpoint any problems.. A moisture meter may help, check every foot or so for a reading after it's run for a while. If you're lucky you'll be able to narrow it down to digging up a few feet at best to fix.

Either way, good luck on finding the problem...

[Dave FL]

Top 1 - 2 feet is fill (construction fill/topsoil) Below that is sandy (In Fla)

Good Point, especially in the sandy soil below.

best to fix.

Especially with almost a 1/2 an acre

Thanks, Dave FL

[Sheldon]

With a leak of that magnitude there would be a very noticable loss of volume at one of more sprinkler heads, have you ever taken the time to observe each head through the entire cycle? Of course your leak could easily be somewhere underground other than the sprinkling system.... I had a house with a cubside water meter and the leak was after the meter but before the pipe entered the house... no surface wet spot but by standing outdoors near the curb I could hear it as plainly as when a toilet is running.

[Dave FL]

Very interesting, although we have two backflow preventers, directly after the meter. I have left both of them on (1-interior & 1-exterior) and turned off the rain bird system and it used no water. I can go to the PDV valve to bypass the control so I know there is constant water to this point. So my leakage must be after the diaphram/solenoids.

Dave FL