To trench or not to trench?

[cross45]

Hello. I have an old Walnut tree in my front yard, about 2.5' in diameter. The local gas and electric company has announced that they have to replace my gas line, which connects to the main line about 3 feet from the trunk, then proceeds for about 30 yards to the back of my house. My husband and I are going to dig up the connection area to try to save as much of the root system there as possible. We have to dig a hole about 3 feet wide and 20" deep. This hole will come to within a foot of the trunk. I understand that we should be alright as long as no roots over 1 inch in diameter are severed. Hope we can pull it off! From the trunk to the house the contractors have offered to either dig a trench 18" deep to lay a new line or to tunnel. The tunnel drill makes a tunnel about 3 feet deep and a couple of feet in diameter. Which would be better for the walnut tree roots, the trench or the tunnel, and what can I do to make sure the tree doesn't die afterwards? Thanks for any educated advice you can give.

 

[D&B Mack]

The tunnel drill makes a tunnel about 3 feet deep and a couple of feet in diameter.

Are you sure about the diameter of the "tunnel"? For a single house service, they should use a "mole" for the line. This will make about a 2" +/- tunnel pending upon the size of your service.

 

[redheadwoodshed]

I would have them tunnel.Even though some roots may be cut either way, in tunneling the roots will be less exposed.

 

[Walt41]

Coat any exposed roots with root gel and make sure the soil goes back in the way it came out to minimize shock.

 

[komatsuvarna]

Even using a hammerhead mole you can't punch 60 yards. A directional drilling machine would be great to use in this case, But they are expensive to operate and use and I doubt the contractors will want to lose money to use it on a 3/4 gas service......I know I wouldn't.


Here's what I suggest. Dig the hole down to the main where the service tap is because this is where their re-connection will be... like was stated. Let them take their mole punch and punch under the tree roots and then dig or trench the rest of the way to the meter. The punch/mole/hole hog (everybody calls it something different) won't hurt any big roots. If it does hit one it will stop moving, then they just have to back it out and try it again in another place.


Its really shouldn't be a big deal. I've had to do similar stuff several times because the last thing the utility district want is a big complaint.....and they last thing the contractors want is a home owner out their raising cain about their tree......but both does happen sometimes no matter what ya try to do.

 

[Raintree]

Air Spade with a good shop vac works well, snake the line under the roots.

 

[komatsuvarna]

Only thing the utility company might kick on is it being a liability issue. If the line is threaded through the roots it could become a hazard. If the tree ever gets blowed over its a real good possibility that it will bring the little 3/4 HDPE service line with it....or actually it would probably break before it pulls it completly out of the ground. You can see where this is going.......

Depends on the utility district or project inspector usually. Some don't care.....Some do care.... they know they are responsible for the service line as long as its there. Every place is different!

 

[cross45]

Thank you to all of you who have offered advice. To my inexperienced mind, it all looks good, especially tunneling with a mole as far as we can. I will run it by the contractor and see what we can work out. If he has to do any trenching, I will make sure to put root gel on the exposed roots and return the soil hopefully to the same place, with the grass on top.

Since they are going to lay a new line (the government is now requiring all metal lines to be replaced with plastic ones), we can pick any route we want for the tunnel/trench. Should we stay away from the main limbs? That is, do the main roots line up with the main limbs if there is no obstacle? Or will they have branched so much that it doesn't matter?

 

[dboyd351]

do the main roots line up with the main limbs if there is no obstacle? Or will they have branched so much that it doesn't matter?

I'm not an arborist, but I'm pretty sure there is no relationship between the location of the roots and the limbs. They are governed by different things, roots grow in the path of least resistance and/or towards water, while limbs try to seek out as much sunlight as possible. If I'm wrong, someone please correct me.