Quick Answer:
If the curb stop partially closes but water continues, don’t force it. Check how far the valve turns, feel for changes in resistance as it travels, and watch the water meter for movement. These steps tell you whether the stop, the meter valve, or an upstream supply is the problem.
Why This Happens
There are a few common reasons a curb stop won’t fully shut off the flow:
- The curb stop stem is damaged, corroded, or worn so it can’t seat fully.
- The valve handwheel or wrench engagement is slipping or not reaching full travel depth.
- A meter or a second valve downstream is stuck open and still allowing flow.
- There is backflow or a secondary feed, such as a private well or a bypass, keeping pressure in the line.
Step-by-Step What to Do
1) Prepare and stay safe
Wear gloves and eye protection. If the curb box is in the street or sidewalk, use traffic-safe practices or wait for the utility if you can’t work safely there.
2) Expose and inspect the curb box
Carefully remove soil or gravel from the box until you can see the top of the curb stop. Clear debris so the wrench seats fully. Don’t pry aggressively on the box; some covers are brittle.
3) Check valve travel depth
Using the correct curb-stop key or wrench, turn the valve slowly and note how many turns it takes to reach a firm stop. If it only turns a small distance before hitting resistance, the stem may be stripped, broken, or the valve may be partially open internally. Keep track of travel depth so you can describe it when you call the utility or a plumber.
4) Feel resistance changes
As you close the valve, pay attention to changes in resistance. A smooth, increasing resistance that ends in a firm stop is typical. A sudden hard stop after a few turns, grinding, or a slipping feel suggests internal damage. If the wrench keeps turning without significant resistance, the stem may be disconnected from the plug.
5) Inspect meter movement
Go to the meter while someone else closes the curb stop slowly. Look at the meter dial or digital register. If the meter continues to register flow after the curb stop is closed, the problem may be the meter or a valve inside the meter assembly. If the meter stops, the curb stop may be working despite residual pressure elsewhere. If you see continued movement, consult resources about a Meter valve stuck open.
6) Rule out other sources
Turn off any inside isolation valves and check for secondary supplies (hot tub fill lines, irrigation systems, private wells, or booster pumps). If the city claims they shut the main but you still have pressure, consider the possibility of an alternate feed and check the situation described in City shut off water but house still has pressure.
7) Next steps if it still flows
If the curb stop won’t seat and the meter shows flow, stop attempting to force the stop. Contact your water utility for a supervised shutoff or hire a licensed plumber to excavate and replace the curb stop assembly.
What Not to Do
- Do not keep forcing buried curb stop — repeated force can break the stem, shear off the valve, or damage the service line.
- Do not use an improvised tool that won’t fit properly; slipping tools can injure you or damage the valve.
- Do not dig carelessly near the service line without knowing exact locations of other utilities.
When to Call a Professional
Call a water utility or a licensed plumber if any of the following apply:
- The curb stop feels stripped, spins without resistance, or breaks.
- The meter continues to register flow after you’ve tried closing the curb stop.
- You’re unsure where the curb box or service line runs, or you see signs of a broken pipe or significant leak.
Utility crews can perform a main shutoff, and plumbers can excavate and replace the curb stop, meter valve, or service repairs safely.
Safety Notes
- Use appropriate personal protective equipment: gloves, eye protection, and visible clothing if working near traffic.
- Avoid standing over an open curb box; soil can collapse and tools can slip into the box.
- If you suspect contamination or a major break, do not use the water and contact your utility immediately.
Common Homeowner Questions
- Why can’t I shut it off fully even after several turns? Internal damage, a disconnected stem, or a stuck plug are common causes — avoid forcing it and document how it behaves for the technician.
- Can I temporarily stop water another way? You can shut off inside isolation valves to stop fixtures, but that won’t stop flow in the service line; for complete isolation ask the utility to shut the main or call a plumber.
- Will replacing the curb stop require digging? Yes. Replacing a curb stop typically requires excavating the box and part of the service line; this is best handled by professionals to avoid hitting other utilities.
FAQs
- My curb stop turns but water still flows — what should I do now? Stop forcing it, check the meter for movement, and contact the utility or a plumber for a proper repair.
- Is it illegal to tamper with the curb stop? In many areas the curb stop is the utility’s property; tampering can be restricted. Check local rules and call the utility if unsure.
- How much does a curb stop replacement cost? Costs vary by location and depth, but expect labor and excavation to be the major expenses; get estimates from licensed plumbers or ask the utility about assistance.