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

[jthread]

is it always wet by the sprinkler heads?

[dadiOH]

Feel the supply lines (to sprinklers) at the manifolds. The pipe will be cooler if water is running (leak) than when not since the ground/sun warms static water in the pipe.

[Dave FL]

A cople of the larger sprinkler heads dribble a little water out while running, but I don't have any real wet spots and the sprinkler pressure doesn't seem any lower

Dave FL

[Dave FL]

Would this be done after I cap off the lines?

[jthread]

check your valves. sounds to me they are getting stuck. they have to be maintained anyway. if a section is dribbling it's not closing all the way.

[BobK207]

Dave-

Unless your water rates are sky high, $400 worth of water is a LOT. By my calcs about 150,000 gallons

If you have a leak somewhere there has got to be a rather large soggy spot.

Are the sprinkler valves electric? Can they be turned off manually (individually)?

I would guess that since the water bill dropped when you "Stopped using the sprinklers" (I assume you cut off water to the sprinkler valve manifold) that the "leak" is a faulty sprinkler valve not a line failure.

You're leaking water at about 3 or 4 gpm.

Are some the heads in one of the zones wet constantly?

cheers Bob

[Dave FL]

Can't find any, it could be possible that since I live in Florida, the soil below 1-2 feet is sandy, and could be soaking it up?

Hunter sprinkler system with a Rain Bird controller

I have checked all of the valves (had to replace one solenoid) and they are not filling up with water when running. I have only turned off the rain bird control, not the incoming water at the backflow preventer (Two knobs, 1 for interior & 1 for exterior)

No, even with the main still on and RB turned off

Dave FL

[Dave FL]

Sorry, what I meant by dribbling was when the zone is on a couple of sprinkler heads dribble water between the top and the shaft. Does this sound right?

Dave FL

[HeyBub]

Does your neighbor have a pool?

Is there a new bog in your neighborhood?

200,000 gallons of water over two months is a LOT of water.

200,000 gallons = 27,000 cu ft = 10'x45'x6' pool, or a little less than half an Olympic swimming pool.

[jthread]

not really. i read your post below and i got to admit i'm stumped. when they leak it's usually a valve. if your water is hard it can cause them to fail pretty quickly. keep at it. it's not that complicated someone will help you. :)

[observer]

Dave, I'm no guru on sprinklers except to say I've had 2 different systems for about 15 years or so, so I have some experience with minor fixes. My instinct would be that if you have that much leakage, you should have a soft spot in your yard where the water is leaking. I think with that much water and under pressure, some water will probably go to the surface as well as below the pipes. You might also see what some diy places for installing systems have to say or google for it.

Last resort, before paying for that much water again, it will probably be A LOT cheaper to get a professional to fix the problem !!

[ransley]

The zone with weak pressure has the leak, follow the pipe and it should be evident from soaked ground.

[JimR]

I suppose in FL with our really sandy soil it may be possible to have a big leak that never shows up on the surface. But before I did a lot of digging and troubleshooting, I'd first do some calculations and make sure that there was something wrong.

1. Did your waterbills suddenly go up to 0-0? What were they before you began to suspect a leak? Has your county put a surcharge on the water bills because of the current drought?
2. How much water did you use with irrigation? without irrigation?

1. You should be able to check your water meter while running a single zone and determine how much water is being put out when that zone is operating. Knowing the number of heads on each zone and their approximate output you should be able to calculate an approximate level of water use. If there is a single source for excessive water use that should become apparent. You should be able to run each zone, determine how much water it puts out during its cycle, compare with your calculations, and if there's little discrepancy, multiply by the number of cycles in a month, and determine your programmed irrigation amounts. If it's totally out of whack with your actual usage you need to look further.

2. Once you know how much water is being used during irrigation, you should be able to determine whether that's an abnormal amount, and then identify which of the zones is/are causing the problem. If you haven't done so, recheck the zone settings on the Rainbird to make sure each zone is only running ~20 minutes, and only on 1-2 x week. If something caused the controller program to go bad, you could be running the system a lot more than originally planned.

1. Once you've (a) identified that there actually is a new problem and (b) identified which zone is at fault, (or perhaps that there is a problem in the manifold or location that might affect several zones) you can trouble-shoot that area .

[dadiOH]

I am not sure what you mean by "cap off the lines". If you mean adjust the sprinklers to zero discharge then no, that is not necessary.

[dadiOH]

I live in Florida too and the amount of water mentioned is a LOT even for Florida sand to soak up. With that much water leaking there must be a joint (or maybe a holed pipe - been digging?) underground that failed but - even in sand - I'd think that would blow out from the surface.

Do you know where the sprinkler supply lines run? If so, walk them.

[Oren]

I've never had one on any of my irrigation systems, but there is/can be what's called a _positive drain valve_ on the end of the zones. Essentially, when the valve shuts off the remaining water drains to a sand pit. The prevents freezing of the pipes.

If you have such a PDV valve and have a bad diaphragm / solenoid on the zone valve, water would leak to ground.

(Not an expert..)

-- Oren

"I wouldn't even be here if my support group hadn't beaten me up."

[Jerry]

No need to remove the sprinkler heads and cap off the risers. Just close the adjusting screw on the top of the sprinkler popup.

Jerry

[Dave FL]

Sounds MUCH easier

Dave FL

[Dave FL]

Sounds like a plausible explanation, but our freeze/thaw in Florida is very minimal.

(Nor am I)