By HomeGuide's 2026 national figures, trenching costs $5 to $12 per linear foot, or $500 to $1,200 for 100 feet. In New Orleans, trenches are easy to dig but fill with water, and soft walls need shoring once they get deep.
Prices here are HomeGuide's published national ranges, not quotes from our company. In New Orleans, groundwater, soft soil, narrow streets, buried debris and the trip to the dump site move the real cost. Checked October 2026.
What does trenching cost for a 100-foot trench?
HomeGuide's national trenching price is $5 to $12 per foot, which makes a 100-foot trench $500 to $1,200. Equipment accounts for about $2 to $3 of each foot and labor for $3 to $9. Groundwater, shoring and buried debris are the New Orleans factors that push the price up.
| Trench length | HomeGuide national range |
|---|---|
| 50 ft | $250 to $600 |
| 100 ft | $500 to $1,200 |
| 200 ft | $1,000 to $2,400 |
Who do I call for a new water line, and what does it cost?
For a water line, call a licensed plumber, who works with an excavator or digs the trench. HomeGuide puts main water line replacement at $2,000 to $5,000, averaging $3,500, or $50 to $200 per foot trenched and $70 to $250 trenchless. Louisiana requires plumbing work to be done by licensed plumbers.
How deep should a water line be buried so it will not freeze?
The plumbing code and your plumber set the depth. Hard freezes are rare in New Orleans but do happen, and exposed pipe under raised houses is what bursts. Insulating pipe under the house and burying the line to code depth in the yard is the protection.
How much does it cost to replace a sewer line?
HomeGuide's sewer page puts replacement at $50 to $250 per foot, or $2,000 to $10,000 for 40 feet, with pipe bursting at $60 to $200 per foot and lining at $90 to $250. A camera inspection, $125 to $500, shows whether the line has cracked, sagged or pulled apart at the house, which is common here as the ground settles.
What does an electric trench to a shed or garage cost?
The trench for an electric line costs the same $5 to $12 per foot as other trenching on HomeGuide's figures. Conduit, wire and depth are the electrician's part. Louisiana requires licensed electricians for that work.
What does it cost to run a gas line underground?
On HomeGuide's trenching page, a buried gas line costs $12 to $25 a foot put in, or $350 to $1,000 or more for a typical run. Gas piping must be installed and tested by licensed professionals, and many older New Orleans homes still have old gas lines to grills, lamps or heaters that need to be found before digging.
Can you bore under the driveway instead of cutting it?
Yes. Boring under a driveway or walk saves breaking the concrete. Directional boring is $10 to $30 a foot on HomeGuide's boring page, so a 100-foot bore runs $1,000 to $3,000. In soft soil, boring works well, but the line still has to stay clear of other buried pipes.
Can water and sewer lines go in the same trench?
Sometimes. Plumbing codes require separation between drinking water and sewer lines, by distance or by height, and the plumber sets the layout. Where the code allows, a shared trench saves digging.
Can you trench near tree roots or close to the house?
Yes, with care. Near live oaks, we route around the main roots or dig by hand and bore under them, because cutting big roots can kill an old oak. Close to a raised house or a slab, we keep clear of the piers and footings and close the trench quickly, since soft soil moves when it is left open.
Want a number for your own lot? We come by, look at the ground and the drainage, and send a written quote. Call or text (504) 608-4795.