Water Line Curb Valve | Sidewalk Valve & How They Function

What is a water main curb valve?

A water main curb valve, also known as a curb stop box is used to control the water supply from the city water main to inside the building.  All new curb valve installations are required to be installed two feet from the curb (when possible) on all fire sprinkler mains as well as domestic water services over two inches in size.  In the event of an obstruction two feet from the curb line, DEP can give special approval to install the curb valve at another location.

When would a curb valve be used?

1. In the event that the fire department has to shut the water off from the outside without gaining access to the building

2. When a plumber has to change the main house control valve and does not want to open the roadway to close the tap connection

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What is a curb key?

A curb key consists of a long metal rod usually 5’ in length with a T shaped handle on the top and a square shape on the bottom to fit over the curb valve operating nut.

How to use a curb key

1. Locate the water main curb box cover and remove the cover from the curb box

2. Locate the curb valve by shinning an industrial flashlight down the curb box – the valve should be approximately 4-5’ below ground level.

3. Place the curb key in the hole and feel around until the squared end is in place over the operating nut, when the key is in place it should feel firmly locked in place.

4. The operating nut should now be turned clockwise to turn off the water. If you feel resistance when turning the valve, you should try to slowly turn the curb key from left to right until you feel the valve start to ease and open.

If you are experiencing any resistance do not use excessive force and call a licensed plumber to assist in opening the curb valve.


At Harris Water Main & Sewer Contractors we pride ourselves in the ability to handle any sized job in an emergency situation when needed. Please feel free to contact us at 718-495-3600 with any questions regarding our services or any general questions your may have.