SPRINKLER TALK FORUM - You Got Questions, We've Got Answers

How big is the leak? ( How many gallons are you loosing per day).
Have you considered a master valve?

Finding leaks is no easy task
Basically it's Inspect visually points of connections and valves> trace out wire in hopes most of the wire follows the main line >Isolate line out> use accoustical equipment and induce air into the system to find the leak.

I'm just going to post what we send to our customers when we discover they have a leak



We determined you have a leak in your sprinkler system. In
the majority of cases, leaks can be found within 1 to 2 man hours depending on the size of the system and
the size of the leak. The bigger the leak is, the easier it is to find. Big leaks usually surface, and when they do
their location is usually obvious. Big leaks also make noise, so if they don’t surface we can hear them using
acoustical leak detection equipment. Smaller leaks are harder to find because they sometimes don’t surface
and because they don’t make noise as they are leaking. A worst case scenario leak is a small leak in a large
sprinkler system that is draining into a footing drain or storm drain. This type of leak is very hard to find
because the water never surfaces and the leak does not make noise. Small leaks like these can take many
hours to locate so the size of the leak determines our strategy for dealing with the leak. Our recommendation
on sprinkler system leaks is to start searching at all the most common places where leaks occur. While most
leaks are found at these locations it must be understood that some leaks won’t be found and either more
searching will be required or the installation of a master valve may be recommended. (See master valves
below)
Step 1) The first step in finding a leak in a sprinkler system is to check the most common places leaks occur
which are at the valves. #1) The POC or point of connection is the valve that isolates your sprinkler system
from the rest of your water system. This is usually the backflow assembly valve. The backflow assembly
valve should be inspected for leaks at pipe fittings, additionally all 4 test cocks which could have been left
slightly opened after backflow testing or winterizing should also be checked. If we just completed a tune-up,
this step can be eliminated. #2) External valve leaks; all zone valves and boxes should be visually inspected
for water caused by external leakage of valves or pipe fittings. #3) Internal valve leaks. In many cases zone
valves leak internally because debris such as rocks or glue prevents them from closing completely. In this
situation water will slowly flow past the zone valve and eventually exit from the lowest sprinkler head on the
zone. The labor involved in checking the 3 most common areas for leaks has several variables. Obviously the
number of valves that require inspection is a factor, the bigger the system, the longer it will take. If you know
where your zone valves are located this decreases the amount of time substantially. If you don’t know where
your zone valves are located then we’re required to trace them using our valve locating equipment. How your
system was constructed can also be a factor. Some installers group valves in large boxes and other
installers use 1 small box per valve. Obviously grouped valves can be located faster then individual valves.
Worst case scenario is rare but in some cases valves are buried in the ground without boxes. Another factor
that can slow down the process is rain. Because rain water can drain into valve boxes, rain water in a box
could be mistaken for a leak, consequently in the wet season it may require that valve boxes are completely
excavated so that the under side of the piping can be visually inspected for leaks.

Step 2) If the leak is not located at any of the valves, then the next step is to mark the location of the main
line. The main line is the portion of the system that is under constant pressure that runs from the POC to the
zone valves. Because sprinkler main lines are almost always constructed from plastic pipe, locating the main
line can be difficult. Luckily the wiring for the valves is almost always located in the same trench as the main
line. So if we don’t find a leak at any of the valves, our next step is to mark with paint the wire runs of the
sprinkler system which is probably where the main line runs but not necessarily. This can be completed in
step 1 if the valve locator was required to find the zone valves. Once the main line has been mapped we can
visually search for obvious wet areas along the main line. One problem with this method is that some
systems will have spurs of main line piping that don’t have wiring; an example is a spur of pipe leading to an
outside faucet.

Step 3) If after completing steps 1 & 2 and no leak is found, then the next step is to document the size of the
leak. We do this by timing your meter and calculating the water loss to determine the water loss per day. If
the leak is less than 120 gallons per day we recommend the installation of a master valve. See below for
more information on the advantages and disadvantages of a master valve. If the leak is greater then 120
gallons per day we recommend continuing the search for the leak. Calculating water loss takes about 5 to 10
minutes.
Step 4) If we determine that your leak is greater then 120 gallons per day we recommend to continue
searching for the leak. At this point we limit our search area by cutting and capping the main line at strategic
points to determine which section the leak is in. Basically for each cut and cap we make, we effectively
reduce our search area by 50%. Each cut and cap and repair takes about 1 hour depending on the diameter
of the main line, commercial systems with larger main lines obviously take longer. So the search area on a
system with a 200 foot main line can be reduced to 50 feet in about 2 man hours. Once we have limited our
search area to around 50 feet of main line we then begin searching using acoustical listening equipment, if all
goes well, then the leak can usually be found within 1 more hour. The louder the leak the faster we can find it.
Limiting factors are noise, the leak detection equipment is very sensitive and noise such as nearby road
noise, jet traffic, garbage trucks and school buses can slow down acoustical searching. Depending on the
size of the system and the size of leak expect this process to take a minimum of 2 man hours.


Master Valves: The best solution to a leak is to repair it, however depending on the size of the leak and the
labor required, repairing is not always a cost effective option. In these cases we recommend a master
valve. A master valve is installed at the point of connection of the system and wires into your sprinkler
controller. Basically the master valve only allows water to flow in your main line (the piping between your point
of connection and the zone valves) when your system’s zones are watering. Now your system only leaks
when the zones are running. The disadvantage to this solution is obvious, you still have a leak in your system
and leaks almost always get bigger as time goes by. The advantages of a master valve are they’re a quick fix
to a majority of water loss caused by leaks. Systems that only run for 1 hour every 2 days are now leaking
1/48 the water that they were leaking before. In contrast systems that have drip zones with long run times or
large commercial systems that run for several hours per day may not benefit as much from a master valve.
Other advantages of master valves are they prevent main line breaks from running continuously or stuck zone
valves from running continuously but the latter can also be considered a disadvantages, since a stuck zone
may go un-noticed and cause the rest of the zones to under irrigate because of lack of pressure. In cases
where master valves are installed we recommend calculating the leak loss yearly and recording this data to
verify the leak is not growing too large. Additionally if you have any hose bibs that draw off the main line of
your system a master valve deactivates them, so this should also be considered before installing one. The
biggest variable to installing a master valve is getting power from the controller to the point of connection. In
many cases we can use a spare wire from one of the valve boxes that is closest to the point of connection. If
no spare wires are available we can use a device called a splitter which allows us to use 1 wire to power 2
valves.

You can purchase sounding rodes and either a phonoscope or stethascope for a cheap price.

Do you have American Leak Detector in your area?
They are expensive but are good

The equipment we have cost us $4k

Even if the leak detector guy lived around the corner it would be very expensive. They charged a customer of mine 1200 dollars to find leak under her patio. She shoulda called me first.
--
If I was you I'd double check the valves to make sure a faulty diaphram or something isn't causing water to flow through a valve. You can get a piece of hose and hold it to the valve and put it up to your ear. Much like finding a vacuum leak under the hood of your vehicle.

Any Other Ideas?

Yeah, get ready to spend some money to find it.

My suggestion is to time your leak and calculate your per day water loss. Then using your water bill rates add it up how much your a spending per month on water loss. If it's within range of what you feel is acceptable on budget loss then just monitor the leak loss on a per month basis ( meaning calculate your leak loss every month to see if it's getting better) Chances are it will surface when the leak gets better. ( Not always the case though)

9 hours a system cycle on probably 2" lats.. A single system cycle must be at least 15,000 gallons usage.
I don't know your yard/system but it really sounds like an audit should be done for your system to use less water.
You must be using a well or a lake otherwise your water bill would be out of this world for a house.

your right, with that long of a run time a master valve doesn't seem to be worth it.

You can Rent a 521 locator to trace out the irrigation wire, this in it self requires experience and skill to accurately locate. Also this doesn't mean the pipe is necessarily there though. Then do spot locates to find the ml... Cut and cap to isolate the leak out.. With a 3" pipe the pipe is large enough to deal with fishing, on the area's where the irrigation wire doesn't follow the pipe you can stick a wire fish inside the pipe and with some effort work around the eblows, couplings, bells - just all the fittings the fish could get caught up on- and continue isolating out.

I don't know anywhere that rents out acoustical equipment, it takes skill to use these devices. But inducing silent air into the system and a low regulated pressure helps immensely on finding the leak with the acoustical equipment.

Like I said get ready to spend some doe to find this leak.

One last thing, did you 100% confirm that the leak is inside your irrigation system by shutting off your isolation valve to the irrigation system and confirm that the water meter only spins when the irrigation iso valve is turned on and not off

jesus.. 600' of head!! ( You can never have too much head tho )

This info would have been nice at the beginning.. You mislead me and the other guy...

I'm guessing you have a submersible pump that pumps the lake water into a 1000gal tank or so and then you have a jet pump that keeps a constant pressure on system.

Just throw a master valve in at the pump and call it good. This way your pump will only kick on when the system turns on.

Good luck with finding your leak