(408) 978-3093

Water Line Replacement in San Jose, CA

Your water service line, also called the water lateral or main water line, runs underground from the meter to your house. When it leaks, loses pressure or is simply old galvanized pipe, we repair or replace it, often by boring under the yard instead of digging a trench.

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  • 1-year labor warranty24/7 service since 1986
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CPI technician working on a water lateral by the curb in Palo Alto, CA

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Water Line Services in San Jose

Repair, replacement and upgrades for the pipe between the meter and your home.

  • Water service line replacement

    Old galvanized, polybutylene or leaking copper service lines replaced with new copper or polyethylene pipe.

  • Trenchless water line replacement

    Directional boring or pipe pulling installs the new line with small pits at each end, saving lawns, driveways and walkways.

  • Water line leak repair

    A single break in a sound line located and repaired. See leak detection.

  • Main shutoff valve replacement

    A seized or leaking main shutoff replaced with a full-port ball valve you can close in an emergency.

  • Pressure regulator installation

    A pressure-reducing valve protects pipes and appliances when street pressure is high.

  • Emergency water line repair

    Water bubbling up in the yard or a sudden loss of pressure? Call our 24/7 line.

Signs Your Water Line Needs Repair or Replacement

Service line problems usually show up in the yard, the bill or the pressure.

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  • Wet spots or puddles in the yard

    Soggy ground, water seeping through a driveway crack or a strip of extra-green grass along the line.

  • Low water pressure everywhere

    Weak flow at every fixture can mean a leak or a corroded, narrowed service line.

  • The meter moves with everything off

    Water is leaving the system somewhere between the meter and your fixtures.

  • Rusty water

    Discolored water at every tap points to an old galvanized service line.

  • A high water bill

    An unexplained jump often traces back to an underground leak.

  • An old galvanized or polybutylene line

    Both are near or past the end of their life in many South Bay homes.

What Is a Water Service Line?

Your home’s water comes from the street main, through the meter, and then through the service line, a buried pipe that runs to the house, usually ending at the main shutoff valve near the front of the home. From there, the house’s own piping takes over. The service line carries every gallon you use, so a leak, a break or a narrowing from corrosion affects the whole house.

Don’t confuse it with the sewer lateral, which carries wastewater out. See the difference between a sewer line and a water line.

Trenchless or Traditional Replacement?

Trenchless replacement uses directional boring, drilling a path underground from one small pit to another, or pulling a new pipe through the path of the old one. Lawns, driveways and walkways stay intact, and the job is usually done in a day.

Traditional replacement digs a trench along the route. It’s the right choice for short, open runs or when the line must be rerouted along a new path.

Upgrades Worth Doing at the Same Time

  • A new main shutoff valve you can actually close in an emergency.
  • A pressure regulator if street pressure is high, protecting fixtures, water heaters and appliances.
  • Upsizing the line if you’ve added bathrooms, an ADU or fire sprinklers.
  • A full repipe if the pipes inside the house are galvanized too, so the new service line isn’t feeding old, rusty pipe.

A Real CPI Example

Our blog post on an emergency underground leak repair in Belmont walks through how our crew found and fixed a leaking underground line.

Sources

Checked October 2026.

How Much Does Water Line Replacement Cost in San Jose?

The price depends mostly on the length of the line, the method and what's above it. A short run across a lawn costs far less than a long line under a driveway. We give you a written fixed price after a site visit.

Typical water line replacement prices in San Jose, installed, in US dollars. Checked October 2026.
ServiceTypical San Jose price (USD)
Finding a leak in the line$150–$600
Flat-rate pricingTypically based on $150–$250 per hour, plus parts and drive time
After-hours flat-rate pricingTypically based on $200–$300 per hour, plus parts and drive time, with a minimum charge
Inspection feeWaived for service plan members$59

What affects the price

  • Length and depth. Longer lines take more pipe, boring and time.
  • Trenchless or trench. Boring saves restoration costs under hardscape and landscaping.
  • Pipe size and material. Upsizing for a larger home or new fixtures costs more.
  • Extras. A new main shutoff, pressure regulator or backflow device.
  • Permit and inspection. Included in our price.

Most repairs are quoted as a fixed price before we start. Ranges are typical for San Jose and the South Bay and don't include current specials.

How Water Line Replacement Works

  1. Inspect and locate

    We test pressure, check the meter for leaks, and locate the existing line and other utilities.

  2. Written price

    We price repair and replacement options, trenchless and traditional.

  3. Permit and utility marking

    We pull the permit and have underground utilities marked before any digging.

  4. Install

    We bore or trench the new line, connect it at the meter side and at the house, and add a new shutoff.

  5. Test and flush

    We pressure-test the new line, flush it and restore water, usually the same day.

  6. Inspect and restore

    We schedule the inspection, then backfill and restore the pits.

Water Lines in San Jose

What San Jose homeowners should know about their water service line.

  • Who owns what

    Generally, your water supplier owns the line up to the meter and you own the service line from the meter to the house (see San Jose Water's split). Most of San Jose is served by San Jose Water; parts of the city by San José Municipal Water.

  • Galvanized service lines

    Many homes from before the 1970s still have galvanized steel service lines that corrode from the inside, reducing pressure.

  • Expansive clay soil

    Valley-floor clay soils shrink and swell with the seasons, stressing older buried pipe.

  • High street pressure

    Where incoming pressure is above 80 psi, the California Plumbing Code requires a pressure regulator on new buildings, and San Jose Water suggests asking a plumber about one for existing homes.

Neighborhoods we serve: Downtown San Jose · Willow Glen · East San Jose · South San Jose · Evergreen · Cambrian Park · West San Jose · Berryessa · North San Jose · Blossom Valley

Current Specials

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What Our Customers Say

Google 4.9 from 130+ reviews: read more →See photos of our work →

  • We had a water service line leak. Danny the technician arrived on time and explained everything to us clearly. He is nice, knowledgeable and professional. He finished the job by himself perfectly and the area was left clean. We would definitely request this technician again when we contact CPI Service in the future.

    Thu L.Google review

  • I have called on CPI multiple times. The first time was a critical emergency to replace hot & cold lines to an outside building which failed due to age and natural deterioration. The second and third times were minor interior jobs. Today they replaced and upgraded the main line from the street to our home. Next, I plan to have them take care of everything for a new home we’re planning to build. These guys are awesome. They can handle any size job. Prices are fair. I like Matt a lot. Attention to detail and quality is fantastic. Highly recommend.

    T. S.Yelp review

  • Danny fixed a broken flange before a water meter that had caused a huge water geyser. He was calm and put in a new flange quickly and effectively. Love working with Danny, who is skilled, knowledgeable, and friendly!

    Julie Q.Google review

Water Line Replacement FAQs

What is a water service line?

The underground pipe that carries water from the meter at the street to your house. It's also called the water lateral or main water line.

Who is responsible for the water line in San Jose?

Generally, the water supplier is responsible up to and including the meter, and the property owner from the meter to the house. Check with your supplier for your address.

Can a water line be replaced without digging up the yard?

Usually, yes. Directional boring or pipe pulling installs the new line through small pits at each end.

How long does water line replacement take?

Most residential replacements are done in one day, with water restored that evening.

What pipe do you use for water service lines?

Copper or polyethylene pipe rated for underground water service, sized for your home's demand.

Should I repair or replace my water line?

Repair a single break in a newer, sound line. Replace the line if it's galvanized or polybutylene, has leaked before, or pressure is poor.

Helpful Guides

Serving San Jose and the South Bay

Our shop is at 2880 Aiello Dr in San Jose. We provide water line replacement across the city and nearby South Bay and Peninsula communities. See our full service area.

Content and prices reviewed October 2026.

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