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How to fix a curb stop leak

We'll confirm the leak location, determine responsibility, try tightening the packing nut for stem leaks, or tell you when to call the utility or plumber.

Troubleshooting · Home plumbing
15–45 min
What you'll need
  • Curb key (long T-handle tool to turn the valve)
  • Wrench (if the packing nut is accessible)
  • Bucket or pump (to clear water from the valve box)
Step 1 of 8

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Steps

Goal: Confirm the leak location, determine responsibility, and fix stem leaks or call the right professional.

Confirm leak location

Goal: Verify the leak is at the curb stop and identify street side vs. house side.

  • Shut off the curb stop with a curb key. If the leak stops, it is on the house side. If it continues, it is on the street side—call the water utility.
  • Good: House-side leak. Proceed to Identify leak type.
  • Bad: Street-side leak—call the water utility. Do not dig without calling 811 first.

Identify leak type

Goal: Determine if the leak is from the stem (packing), valve body, or connections.

  • Turn the curb stop back on. If water leaks from around the valve stem, it is a packing leak—you can try tightening the packing nut.
  • If water leaks from the valve body or pipe connections, call a plumber.
  • Good: Stem leak. Proceed to Tighten packing nut.
  • Bad: Body or connection leak—see When to get help.

Shut off the main

Goal: Reduce pressure before working on the curb stop.

  • Shut off the main shutoff valve inside the house (often in the basement or crawl space). Open a faucet to confirm water stops.
  • Good: No water flow. Proceed to Tighten packing nut.
  • Bad: Main valve stuck—call a plumber.

Tighten packing nut

Goal: Stop water leaking from around the valve stem.

  • Use a curb key or wrench to reach the packing nut—the nut around the valve stem. Turn it clockwise a quarter turn. Do not overtighten—the valve must still turn.
  • Turn the curb stop back on. Check for leaks.
  • Good: No drip from around the stem. Proceed to Verification.
  • Bad: Still leaks—the packing may be worn. See When to get help.

When to get help

Call the water utility if:

  • The leak is on the street side of the valve.
  • The valve body or connections leak.
  • The valve is buried or inaccessible.
  • You are unsure who owns the valve.

Call a plumber if:

  • The stem still leaks after tightening the packing nut.
  • The valve body or connections leak (house side).
  • You are not comfortable working near the street.

Do not dig around the curb stop without calling 811 to locate underground utilities first.

Verification

  • No water drips from the curb stop when the valve is on.
  • The valve turns freely with the curb key.
  • No new leaks at the valve or connections after 24 hours.

Escalation ladder

Work from the device outward. Stop when the problem is fixed.

  1. Confirm leak location Verify the leak is at the curb stop and identify street side vs. house side.
  2. Identify leak type Stem leak = try tightening packing nut. Body or connection = call pro.
  3. Tighten packing nut Quarter turn on the packing nut for stem leaks.
  4. Call water utility Street-side leak, valve body leak, or unsure—call the utility first.
  5. Call a plumber House-side valve body leak, stem still leaks after tightening, or not comfortable.

What to capture if you need help

Before calling support or posting for help, have these ready. It speeds everything up.

  • Leak location (stem, body, or connection)
  • Street side or house side
  • Packing nut tightening result
  • Steps already tried

Is the leak at the curb stop valve?

The curb stop is in a valve box near the street. Water may come from the valve, meter, or pipes.

Locate the curb stop in the valve box. Check that water comes from the valve or its connections—not from a broken pipe or meter. Good: leak at curb stop. Bad: leak elsewhere—see how-to-find-water-leak or call a plumber.

Yes No

You can change your answer later.

Is the leak on the street side or house side of the valve?

Shut off the curb stop. If the leak stops, it is on the house side. If it continues, it is on the street side.

Shut off the curb stop with a curb key. Leak stops: house side—your responsibility. Leak continues: street side—call the water utility. Do not dig without calling 811 first.

House side Street side

You can change your answer later.

Call the water utility

Call your water utility. Provide your address and describe the leak. Many utilities own or maintain curb stops and will repair street-side leaks. Do not dig around the valve—utility lines may be nearby.

Done

Is the leak from around the valve stem?

Stem leak = packing. Body or connection leak = call plumber.

Turn the curb stop back on. Leak from around the stem: try tightening the packing nut. Leak from valve body or connections: call a plumber—do not attempt DIY.

Yes (stem) No (body/connection)

You can change your answer later.

Tighten the packing nut

Quarter turn clockwise. Do not overtighten—the valve must still turn.

Shut off the main inside the house first. Use a curb key or wrench to tighten the packing nut a quarter turn clockwise. Turn the curb stop back on. Good: no drip. Bad: still leaks—call a plumber; packing may need replacement.

Yes No

You can change your answer later.

Leak is resolved

The curb stop no longer leaks. Monitor for 24 hours. If it weeps again, the packing may be worn—call a plumber.

Done

Call a plumber

Call a plumber if: the valve body or connections leak, the stem still leaks after tightening, or you are not comfortable. The plumber can coordinate with the utility if the curb stop needs replacement.

Done

Call a pro

Call the water utility if the leak is not at the curb stop or is on the street side. Call a plumber if the leak is elsewhere on the main line. Do not dig without calling 811 to locate utilities.

Done

Reviewed by Blackbox Atlas

Frequently asked questions

What is a curb stop?
The curb stop is the valve that controls water flow from the street main to your property. It sits in a valve box near the curb or sidewalk, often in the same box as the water meter. It is used to shut off water to the house for repairs.
Can I fix a curb stop leak myself?
You can try tightening the packing nut if water leaks from around the valve stem when the valve is on. If the leak is on the street side of the valve, from the valve body, or the valve is buried or inaccessible, call the water utility or a plumber. Do not dig around the valve without contacting the utility first—there may be gas or other utilities nearby.
When should I call the water utility for a curb stop leak?
Call the water utility if the leak is on the street side of the valve, the valve body is leaking, the valve is buried or inaccessible, or you are unsure who owns the valve. Many utilities maintain curb stops and will repair them at no charge.

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