Main Water Line Repair
A failed main water line means low pressure or no water at all, and often a wet patch in the yard that never dries. Repairs run $900 to $3,500 and full replacement $2,500 to $8,000, with trenchless methods avoiding most of the yard damage.
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How urgent is this? Complete water loss is an emergency. A slow leak with adequate pressure is urgent but can typically be scheduled during standard hours, which costs meaningfully less.
Typical cost: $900 to $8,000 nationally. A single accessible spot repair sits at the low end. Full replacement dominates the high end, and going under a driveway, sidewalk, or street adds permitting, traffic control, and restoration costs that can exceed the plumbing itself.
Warning signs
- A sudden or gradual drop in water pressure throughout the house
- A persistently wet or unusually green strip of yard between the meter and the house
- The water meter running continuously with all fixtures off
- Discolored or gritty water after a pressure change
- Complete loss of water to the building
What causes it
- Corrosion of galvanized steel or older copper service lines
- Ground movement, settlement, or freeze heave shearing the line
- Tree root pressure crushing or displacing the pipe
- Excavation damage from landscaping or other utility work
- Age-related failure of polybutylene service lines, which fail without warning
What to do before the plumber arrives
- Check whether neighbors also have low pressure, which points to a utility main problem rather than your line
- Locate your meter and check whether the dial is moving with everything off
- Note where any persistently wet patch appears in the yard
- Contact your utility first if you have no water at all; the problem may be on their side and free to fix
- Have utility locates marked before any excavation, which is legally required nearly everywhere
What the plumber will actually do
Confirm the line is the problem
Pressure is checked at the meter and at the house to establish that the loss is in the service line rather than inside the building or on the utility side.
Locate the leak
Acoustic equipment and line tracing pinpoint the failure and map the route, so excavation happens in one place rather than along the whole run.
Choose repair or replacement
A single failure in a sound line can be spot repaired. A corroded galvanized or polybutylene line will keep failing, and replacement is the honest recommendation.
Execute the work
Options are open-cut excavation, or trenchless pulling of a new line through the existing path, which spares driveways, walkways, and mature landscaping.
Pressure test, disinfect, and restore
The new line is pressure tested and disinfected before being placed in service, and the excavation is backfilled and restored.
Water line repair FAQ
Where does my responsibility for the water line start?
Almost universally, the utility owns the line up to and including the meter, and the property owner owns everything from the meter to the house. If your problem is on the street side of the meter, call the utility before you call a plumber, because that repair should not cost you anything.
What is trenchless water line replacement?
A new line is pulled through the path of the old one, or through a bored path, with excavation limited to a pit at each end. It costs more per foot than open trenching but usually less overall once you count restoring a driveway, a mature lawn, or hardscaping that open-cut would destroy.
How do I know if I have a polybutylene service line?
Polybutylene is typically gray, blue, or black flexible plastic, usually stamped PB2110, and was installed widely from the late 1970s into the mid-1990s. It fails unpredictably from the inside and is not repairable in any lasting way. If you find it, plan replacement rather than waiting for the failure.
Why is my water pressure low but the line is not leaking?
Corroded galvanized service lines narrow internally with rust and scale until flow drops even though the pipe is not leaking at all. The pipe is technically intact and functionally failed. Replacement is the only fix, and low pressure with no leak on an older galvanized line is close to diagnostic.
Related services
- Emergency Leak DetectionNon-invasive location of hidden water leaks behind walls, under floors, and beneath slabs using acoustic, thermal, and pressure testing equipment.
- Emergency Burst Pipe RepairA burst pipe releases water continuously until the supply is shut off. Emergency repair covers isolation, pipe section replacement, and pressure testing.
- Whole-House RepipingReplacement of a home's supply piping where the existing system has reached end of life, using PEX or copper.
- Frozen Pipe Thawing and RepairProfessional thawing of frozen supply lines, plus inspection and repair of any sections that split while frozen.
Emergency guides
- How to Shut Off Your Water in an EmergencyFind and operate your main water shutoff before you need it. The single most valuable thing a homeowner can know during a plumbing emergency.
- Why Your Water Bill Suddenly Went UpA jump in water usage with no change in habits almost always means a leak. How to find it yourself, in order of likelihood.
Cost guides
- Sewer Line Repair and Replacement CostWhat sewer lateral repair costs by method, including trenchless lining and pipe bursting, and how to compare quotes honestly.
- Slab Leak Repair CostWhat it costs to find and fix a leak under a concrete foundation, and when rerouting beats repairing in place.
- Whole-House Repiping CostWhat it costs to replace a home's supply piping, how PEX and copper compare, and the scope question that causes most disputes.
Common questions
- Drain and Sewer QuestionsBlocked drains, main line backups, recurring clogs, and what not to put down them.
- Leak and Pipe QuestionsHidden leaks, high water bills, frozen pipes, slab leaks, and when a system needs repiping rather than repair.
- Hiring and Licensing QuestionsHow to verify a plumber, what to ask before dispatch, and the pressure tactics worth refusing.
Related articles
- What Emergency Plumbing Actually Costs, and WhyA plain breakdown of after-hours rates, call-out fees, and the four questions that change your invoice.
- Your Water Heater Is Telling You It Is About to FailTank heaters give several months of warning before they flood a floor. The signs, in the order they usually appear.
- If Your Basement Backs Up When It Rains, Your Pipes Are FineRain-correlated sewer backups are a municipal capacity problem, not a blockage. Clearing your line will not stop it.