How to dig an irrigation trench, and not cut pipes, phone wires, your cable TV etc

Article By Shorty


So here is the problem, one of my sprinkler irrigation pipes broke underneath my back porch, and I needed to re-route it around the porch, and splice in with another pipe which I didn't know exactly where it was. I am pretty good and quick with a pick axe, but there doesn't seem to be a gentle way to dig a trench without busting thru whatever is underground. I asked everyone if they knew a way to dig a trench without cutting into previously laid pipe and wires, but nobody had a solution except one guy said "dig with a pickaxe gently", and anther guy said that he just uses a power trenching tool and repairs whatever he cuts, or lays out new pipe & wires in the new trench and abandons the stuff he destroys.

So here is a solution I discovered one day when digging a hole. One trick I was told was to fill the hole up with water and let the dirt get moist, then it is easier to dig more. I was doing that and noticed that when the sprayer was pointing at the side of the hole, it would easily cut into the dirt. Then I started going in a line from there and came up with this method.

Here are the tools that are needed - a trenching shovel, a bottomless plastic jug, and a pressure nozzle that screws to the end of a garden hose. These are advertised to be used for cleaning off your driveway, they create a high pressure stream - costs only $2. Also the yellow thing is an inline ball valve so I can shut off the water right there and not have to walk back to the nozzle at the house.

First thing I do is dig a narrow hole that is just big enough for me to bail water out of, with my bottomless jug. Then I use the spray nozzle to cut into the dirt along the path that I want to trench.

The water flows down hill and into the hole I dug, which I can then bail the water out of.

Hey look at that - water that floats in the air. :)

After a few cycles of spraying and bailing, you end up with a thin, narrow, deep trench.

As you can see from the picture, I was able to locate the irrigation pipe without breaking it. Even the small tree roots are still intact.

The only drawbacks to this is that you displace a lot of the dirt, it gets distributed around your throwing radius. Possibly if you had a big barrel, you could put the water and dirt in there so you could seperate it and put the dirt back in your trench. I have a big pile of dirt in my back yard from digging my pond so I just get some from the pile to fill the trench back up again.

How to dig a hole and get a pipe under your
driveway or sidewalk, without breaking it

While figuring out the method above for digging tranches, some friends told me about a similar technique for drilling a hole thru the dirt under your driveway - so you don't have to cut thru the concrete and re-patch it. What you do is attach a pressure nozzle to the end of a piece of PVC pipe. Same kind of nozzle I used for the trench project. Attach garden hose to the other end, turn the water on and it acts like a big drill bit.

Makes a huge mess, but can drill a hole thru the mud so you can fish a pipe in thru there, or wires or whatever.