Nationally, HomeGuide's 2026 trenching page lists $5 to $12 a running foot, which is $500 to $1,200 for a 100-foot run. In San Antonio, a trench through clay goes fast; one through caliche or limestone can cost far more per foot.
All prices on this page are national ranges from HomeGuide, not quotes from us. In San Antonio, limestone, caliche, black clay, access and haul distance decide where a job really lands. Figures checked in October 2026.
What is the trenching cost for 100 feet?
HomeGuide puts trenching at $5 to $12 per linear foot, so a 100-foot trench costs $500 to $1,200 nationally. About $2 to $3 per foot is equipment and $3 to $9 is labor, which runs $35 to $65 per hour. Rock, depth and obstacles are what change the price.
| 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 trench, and what will it cost?
For a water line, call a licensed plumber, who will dig or bring in an excavator for the trench. HomeGuide's water line page puts main line replacement at $2,000 to $5,000 with a national average of $3,500, which is $50 to $200 per foot trenched and $70 to $250 per foot trenchless. Texas requires a licensed plumber for the pipe work.
How deep should a water line be buried to keep it from freezing?
The plumbing code and your plumber's plans set how deep the line goes. San Antonio rarely freezes hard, but the February 2021 storm broke water lines across the city, mostly where pipe was shallow or exposed. Code depth below ground and insulation on exposed pipe near the house are the protection.
How much does sewer line replacement cost?
HomeGuide lists sewer line replacement at $50 to $250 per linear foot, or $2,000 to $10,000 for 40 feet. Trenchless options are $60 to $200 a foot for bursting and $90 to $250 for lining. A camera inspection, $125 to $500, finds the break before any digging starts.
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 by HomeGuide's figures. The electrician supplies and installs the conduit and wire and sets the depth. In rock, the trench may be cut with a rock saw to reach that depth.
What does it cost to run a gas or propane line?
An installed gas line runs $12 to $25 per foot, or $350 to $1,000 or more, on HomeGuide's trenching page. In Texas, a licensed plumber must install and test gas piping. Propane tanks on acreage come with placement rules from the supplier and the state.
Can a line go under my driveway without cutting it?
Yes, by boring under the driveway. HomeGuide lists directional boring at $10 to $30 per foot, or $1,000 to $3,000 for 100 feet. Boring works well in soil and clay; solid limestone under the drive can make it slower or force a different route.
Can water and sewer lines share the same trench?
Sometimes. The plumbing code requires separation between water and sewer lines, either by distance or by setting the water line higher, and the plumber decides the layout. When it meets code, one trench saves digging.
Can you trench near tree roots or close to the house?
Yes, carefully. Near live oaks, we route around the main roots, hand dig or bore under them, and paint any wound on an oak root or trunk, as Texas A&M Forest Service advises against oak wilt. Close to the house, we stay off the footing and backfill the same day.
To get a number for your own site, have us walk it first; the price comes in a written quote. Call or text (210) 796-2675.