Efficient ways to trace buried sprinker lines?

[Stephen Tashiro]

Is there a an efficient way to trace the path of buried PVC sprinkler lines?

At a friend's house, there is an old sprinkler system that nobody knows anything about. The location of the electronic timer and the location of a box in the ground with one electric valve in it are known. The location of the sprinkler heads are known. However it's unknown where the rest of the electric valves are and where the sprinkler lines connect to the main water supply.

As far as having a sprinkler system, the best solution for my friend is to install a completely new one. However, I wonder how "the pros" go about tracing sprinkler lines when they need to. I might try their methods, just out of curiosity.

[Bill Dufour]

Maybe turn them on and use a spike to listen for flow. You could use a battery operated fox and hound to trace the control wires.
Bil lD

[Steve Eure]

If they are electric low voltage wire buried you can use a pipe horn if you know anyone who has one. I don't know if you can rent one anywhere.

[Bill Dufour]

seems like something you could train a dog to listen for.
Bil lD

[Lee DeRaud]

PVC pipe tends to get laid in more-or-less straight lines, and minimizing the amount of trench to be dug factors high in the planning. Just dig around each head and see what direction the pipes come from...connect the dots.

The connection to the supply will be near either (1) where the supply enters the house or (2) a hose bib. (I have two, one of each.) The valves will be between that/those spot(s) and the first head in the circuit. (My preference is to have them all as close to the supply as possible to minimize the amount of pipe under constant pressure.)

[Kev Williams]

make a couple of divining rods out of some welding rod. The results might surprise you. :)

When I was a kid I watched a guy find a water main and tee valve alongside a dirt road with them, the hole he dug down was right on the money...

[Lee Schierer]

make a couple of divining rods out of some welding rod. The results might surprise you. :)

When I was a kid I watched a guy find a water main and tee valve alongside a dirt road with them, the hole he dug down was right on the money...

You can also use a couple of old coat hangers bent in a "L" shape. I have some that a phone technician left on our property that are made from heavy gauge copper that work really well. Hold them in loosely your hands with one leg of the L pointing straight out ahead and level to the ground. The piece in your hand should point down. As you walk over a water line the wires will swing in toward each other and then separate as you walk past the water line. You may also find electrical lines this way. It is spooky, but it works.

[Stephen Tashiro]

Maybe turn them on and use a spike to listen for flow. You could use a battery operated fox and hound to trace the control wires.
Bil lD

On the one electric valve that can be found, I unscrewed the bleed screw all the way and no water appeared anywhere. So I think there is no water in the system. The control box has power to it and it sends power to wires connected to it, but nothing happens.



PVC pipe tends to get laid in more-or-less straight lines, and minimizing the amount of trench to be dug factors high in the planning. Just dig around each head and see what direction the pipes come from...connect the dots.

We've done this around several sprinker heads. However, in the yard in question, this is tough work. The soil is hard, dried clay.




The connection to the supply will be near either (1) where the supply enters the house or (2) a hose bib.

It's definitely not at a hose bib. As is the custom in local houses from the 1950's, the man water line probably runs parallel to the main sewer line. The city's water meter box is located near the sidewalk at the front of the house. There are sewer clean outs near the front wall of the house. The path between the box and the cleanouts is about 35 ft long. We see no box for a water valve along this path.

The control box is mounted outside on the back wall of the house. The one electric valve we've found is in the backyard.

[Stephen Tashiro]

If they are electric low voltage wire buried you can use a pipe horn if you know anyone who has one. I don't know if you can rent one anywhere.


That's an interesting idea. The control box sends 24 V AC to wires connected to it. Can you post a link to a type of "pipe horn" that can detect that?

[Frank Pratt]

A utility locating service can locate anything with a wire underground. It's not terribly expensive either.

[Lee DeRaud]

On the one electric valve that can be found, I unscrewed the bleed screw all the way and no water appeared anywhere. So I think there is no water in the system. The control box has power to it and it sends power to wires connected to it, but nothing happens.That sounds suspiciously like there's a (manual) master shutoff valve for the system somewhere, presumably right at the supply connection. You really need to find that...if there's a basement/crawlspace, it may be inside.

First step in the diagnosis is seeing if there is 24V coming out of the controller, then cycle through the circuits and check for 24V at the one valve.


We've done this around several sprinker heads. However, in the yard in question, this is tough work. The soil is hard, dried clay.Well, look at it this way: it's way easier than a new install is going to be. :)

[Von Bickley]

Two metal coat hangers will find water lines, electric lines and telephone lines. Watch some you-tube videos. I have tried it and it works.

[Tom M King]

If you slice off a streak of sod with a square point shovel, you can see where an old trench is, and then lay the sod back in place. In an extreme case of finding a water line, I scraped the top off of the ground with my loader bucket in a driveway. It turned out that water line went into the next door neighbor's yard, and then came back in. Fortunately, that was under a gravel driveway, so I just spread the gravel back out when we finished. That line was nowhere close to where anyone thought it was.

[Perry Hilbert Jr]

yep two pieces of steel wire about 28 or 30 inches long. bent with a 4 inch "L" on each. hold one in each fist with your hands together and the wire extending straight out parallel and sllghtly down ward. When you walk over a buried line or place where the ground had been disturbed the wires will swing, either apart or to cross each other. I learned this trick when I was a kid 60 years ago. I found buried water lines for people, found septic tanks, buried electrical lines etc. It works for most people and No I don't have a clue why, but I have shown many how to do it. What's fun is when the doubters try it and it works. Some say it is dousing to find water. It isn't. It finds where trenches or holes have been dug. Heck it is fun just to show the kids. My 6th grade teacher swore it was BS. I took two wire rods to school and demonstrated it as well as found where the water line came from the street and under the playground to the school. He pulled out the old design plans and I was on the money. Heck teach kids to do it. They need to believe in something without a solid explanation.

[John K Jordan]

make a couple of divining rods out of some welding rod. The results might surprise you. :)

When I was a kid I watched a guy find a water main and tee valve alongside a dirt road with them, the hole he dug down was right on the money...

My neighbor can trace water lines with divining rods. He uses copper, bent in an "L" shape. I watched a utility guy locate a water line like that too. I couldn't make it work.
I don't think it will work unless the lines are full of water, perhaps an issue for an unused sprinkler system.

I did watch a cemetery custodian use two divining rods to locate my grandmother's grave. I tried it and that worked for me. When the rods moved it felt like magic.

JKJ

[Jim Koepke]

My own observations with the L-rods is to hold them so they can move on their own.

My body has always been susceptible to static discharge, not sure if that might have some influence on dowsing.

jtk

[Roger Feeley]

The main shutoff valve would be metal. It could be that the grass has grown over the valve box and you just can’t see it. Borrow a metal detector and see if you can find it. That would bring water to your valve manifold.

you said that you have found one electric valve. How many zones are on the controller? If there are multiple zones, how many low voltage wires are coming out of the controller? You may need to locate more valves. Again, a metal detector would be helpful. Those valves have some metal.

[Ole Anderson]

Good luck. I have been working on my system since I installed it 45 years ago. Straight line sprinkler to sprinkler will work about 75% of the time, but if there is a tee mid-pipe, all bets are off. Most of my pipe failures are a result of tree roots pinching off a line, once they start a small leak, roots will migrate to that source of water and it becomes a real struggle to excavate to a line buried even 9 inches with all of the roots in the area. I found a sawzall with a pruning blade works ok until it dulls. Dowsing seems to be highly dependent on the skill and karma of the individual.

My golf buddy just got a quote to install a sprinkler system with a lake pump, not a huge lot. $4500. Yikes. That is why I tend to DIY.

[Bill Dufour]

With only one vale it could be using seqimatic valves downstream. Unlikely, I think FMC quit making them in the early 1970's. I am not sure if a sequimatic valve has any metal in it at all.

[Doug Dawson]

Is there a an efficient way to trace the path of buried PVC sprinkler lines?

At a friend's house, there is an old sprinkler system that nobody knows anything about. The location of the electronic timer and the location of a box in the ground with one electric valve in it are known. The location of the sprinkler heads are known. However it's unknown where the rest of the electric valves are and where the sprinkler lines connect to the main water supply.

As far as having a sprinkler system, the best solution for my friend is to install a completely new one. However, I wonder how "the pros" go about tracing sprinkler lines when they need to. I might try their methods, just out of curiosity.

There are tools you can use to follow the wiring from the controller to the valve controlling a zone, basically listening to an oscillator signal.

Beyond that, you’re assuming a common-sense path connecting the plumbing to the sprinkler heads. “What would the installers have done?” Assuming they weren’t knuckleheads. That’s what you have to go on. You could try to get the original schematic from them, if they were conscientious and still in business. Alternatively, dig around the sprinkler heads and “connect the dots.” Unless they were trying to be mischievously annoying.

So-called “water dowsing” is a well-known fraud. Good luck with that.

For the curious: https://en.wikipedia.org/wiki/Dowsing

[John K Jordan]

... Alternatively, dig around the sprinkler heads and “connect the dots.” Unless they were trying to be mischievously annoying.


Or they ran into something underground which required a detour, underground wiring, big rock, old foundation.

[Doug Dawson]

Or they ran into something underground which required a detour, underground wiring, big rock, old foundation.

I would file that under the category of “mischievously annoying”. You can’t always win.

[John K Jordan]

Or they ran into something underground which required a detour, underground wiring, big rock, old foundation.


I would file that under the category of “mischievously annoying”. You can’t always win.

A couple of weeks ago I had an annoying little rock about an inch high and 4" in diameter in the way of some leveling so I pushed it with the tractor. Not a budge. I ended up digging out a rock about 4' x 2' x 2'.

The same thing happened maybe 10 years ago when putting in a road and a small rock was about 2" higher than I wanted the grade for drainage. I ended up digging out a rock I so big I couldn't lift it with the skid steer. I had to dig a shelf on one side, dig an access ramp on down into the ground on other side and roll the rock onto the shelf. I repeated this several times, each time filling in the ramp and making a higher shelf. Eventually I rolled the rock into the woods where it sits today. I filed it under "incredibly annoying but way too stubborn to give up." Anyone who wants a large rock can come get it.

JKJ

[Doug Dawson]

A couple of weeks ago I had an annoying little rock about an inch high and 4" in diameter in the way of some leveling so I pushed it with the tractor. Not a budge. I ended up digging out a rock about 4' x 2' x 2'.

The same thing happened maybe 10 years ago when putting in a road and a small rock was about 2" higher than I wanted the grade for drainage. I ended up digging out a rock I so big I couldn't lift it with the skid steer. I had to dig a shelf on one side, dig an access ramp on down into the ground on other side and roll the rock onto the shelf. I repeated this several times, each time filling in the ramp and making a higher shelf. Eventually I rolled the rock into the woods where it sits today. I filed it under "incredibly annoying but way too stubborn to give up." Anyone who wants a large rock can come get it.


I would have started out with an SDS rotary hammer. Nice tool to have around, particularly the SDS Max units. Shatter that rock. Impose your will upon the gifts of the earth. :^)

Also useful for trenching, I hear.

[Tom M King]

I used a big rock for a subdivision sign once. We have an abandoned rock quarry, with all sizes of rocks. I had my Wife go pick out a suitable rock, with a nice big, flat side to mount the letters on. I had a guy working with an old Cat 955 loader, and tandem dump truck, that was about as crazy as I am. He could grab the rock with the loader, but he couldn't quite pick it up and keep the tracks on the ground.

I went to the local store, and got about 8 guys to come and hang onto the back of the 955. He was able to pick the rock up, but it was too big to get all the way in the back of the dump truck. Using all his chains, and binders, and all my chains and binders, we were able to secure it hanging out the back of the big dump truck.

Fortunately, that subdivision was only a couple of miles from our place, and he made it over there without dropping it. When you are driving up the hill towards where that subdivision is, the rock is sitting right at the top of the hill. You turn left to get into that subdivision right in front of the rock.

I was developing it to have some where to build spec houses for several years. That was when things were going so crazy in the building business, prices on lots were going crazy too. Long story shortened, I sold the whole subdivision to another builder outfit that was a lot smarter than me, for twice per lot what I was planning to sell them for when I built a house on them. That stone is still sitting there with no sign on it.

An SDS Max drill will go right on down into Granite, but a rock drill does better.

[John K Jordan]

I would have started out with an SDS rotary hammer. Nice tool to have around, particularly the SDS Max units. Shatter that rock. Impose your will upon the gifts of the earth. :^)

Also useful for trenching, I hear.

Yes, I have industrial SDS rotary hammers. Used one just a few days ago to drill in concrete. I've use the chisels in non-rotary mode to cut long channels in concrete for drains.

However, my latest rock removal was a long way from electrical power. My excavator carries it's own power running on diesel. Digging and removing the rock took only a few minutes while I relaxed in the air conditioned cab and listened to the radio.

My neighbor was thrilled to get the rock. So far I've given him multiple tons of rocks for landscaping. He loves the way I can set a 1-ton rock down exactly where he wants it.

JKJ