Model plumbing codes require a shutoff on the building water service pipe near the curb and a building-side main shutoff at the service entrance; local jurisdictions enforce the exact locations and wording, so check your adopted code before you work on the service line or curb stop [1][3].
What owners should know before touching anything underground
Municipal utilities commonly treat the curb stop/curb box as accessible to both the utility and the property owner, but policies on operation, locating, and replacement vary — some utilities will locate or operate the curb stop for a fee while others expect the customer or a hired plumber to maintain access [4][12][13].
Before attempting to replace a buried curb stop or service-side valve, contact your water utility: the curb stop may be utility-owned or the utility may need to isolate the street-side supply to prevent uncontrolled flooding. Do not operate or remove a buried curb stop without utility coordination [4][12][13].
Common risks of DIY curb/service shutoff work
Buried or seized valves that are difficult or impossible to turn or remove without excavation and specialty tools [4].
Higher pressure on the street/service side and the risk of uncontrolled flooding if the utility side is not isolated before opening or removing the valve [4].
Work in the public right-of-way or meter alterations that may require utility crews, permits, or street permits — increasing complexity and cost [11][9].
Because of these risks, utilities and trade guides recommend licensed plumbers and prior utility coordination for curb or underground service work [4][11].
Step-by-step procedure most guides recommend
Locate the curb box and curb stop. Verify whether the curb stop is in the public right-of-way and whether the utility will operate or locate it for you [8][4].
Contact the water utility and request their guidance or an isolation at the curb box. The utility may have a formal process or fee for locating or operating the curb valve [4][12].
Shut off the building-side main (inside the house) and drain downstream fixtures and low points so the section you will work on is dewatered [8][11].
After the utility has isolated the street side (if required), expose and replace the valve per manufacturer drawings and installation instructions; matching the correct connection type (flare, compression, NPT, etc.) to the existing service pipe is essential [6][7].
Have the utility restore pressure and test the new valve under system pressure; if meter or backflow devices are involved, follow utility instructions and any required inspections [4][11].
Parts, manufacturers, and matching connections
Manufacturers such as Mueller and Ford publish product drawings and installation guidance showing valve types, connection methods (flare, compression, threaded), and required packing/gaskets — use those drawings to match replacement parts to your existing service line rather than guessing compatibility [6][7].
Temporary bypass options and who typically provides them
Contractors and utilities sometimes install temporary bypass piping at the street/distribution level to keep multiple services active during larger municipal or contractor projects; this is a common contractor/utility practice but not a typical homeowner DIY solution [11][5].
A homeowner-level "bypass" for a single-valve replacement usually depends on the utility shutting off or isolating the curb stop so the building-side valve can be changed safely — full bypass piping at the street is normally outside homeowner scope and requires utility coordination [4][11].
Permits, inspections, and who usually pulls them
Replacing a main/service shutoff often triggers plumbing or water-service permits and inspections — especially when excavation, working in the public right-of-way, meter alteration, or service replacement is involved. Licensed plumbers typically pull the required permits as part of the job [1][3][9][11].
Typical consumer costs and what raises them
Consumer-facing cost estimates put routine main shutoff replacement in a typical range around $250–$600; higher-end jobs that require trenching, curb-stop coordination, full service-line work, meter changes, or deeper excavation commonly climb well above that (examples show jobs in the $550–$1,200+ range), and permit fees vary by municipality and can add roughly $50–$500 in examples shown by consumer guides [9][10][11].
Emergency work, deep trenching, or full service-line replacement increases labor, equipment, and permitting costs substantially beyond a small-valve swap [9][11].
When to hire a licensed plumber or contact the utility
Hire a licensed plumber (and coordinate with the utility) if the curb stop is buried, seized, or in the public right-of-way, if the job requires excavation or a street cut, or if meter or backflow devices must be altered [4][11][1].
Call the utility first when the curb stop ownership or location is unclear, when you expect the work will affect the street-side supply, or when the utility's procedures require crew involvement to isolate, locate, or operate the curb stop [4][12].
If your work will involve a meter or backflow device, follow utility requirements and inspection schedules; see our guide on backflow prevention for related testing and device considerations.
Practical planning checklist (quick)
Confirm who owns the curb stop and whether the utility must isolate it — contact the utility and follow their procedure [4].
Decide whether the valve can be reached without a right-of-way excavation; if not, plan for permits and a plumber [11].
Match replacement valve type and connection to existing service using manufacturer drawings [6][7].
Get permit estimates and a written cost estimate that separates valve labor, excavation, utility fees, meter work, and permit costs [9][10].
Schedule utility isolation and an inspection slot, then have the installer test the new valve under system pressure when the utility restores service [4][11].
Final notes — realistic expectations
Replacing a visible indoor main shutoff is often straightforward; work on curb stops and buried service valves commonly requires utility coordination, possible permits, and a licensed plumber because of ownership, safety, and right-of-way rules [1][4][11].