The Ultimate Guide to Underground Water Shut-Off Valve Types & Installation

Choosing the right underground water shut off valve types is essential for maintaining a safe and efficient water system. Whether you are a contractor or a homeowner, understanding these valves is key to emergency preparedness.

Underground water shut-off valves are critical components in residential, commercial, and municipal water systems. They allow you to stop the water supply from the street or underground piping—especially during emergencies, repairs, winterization, or property maintenance.

This guide explains what underground shut-off valves are, how curb stop valves work, their types, how to install them, and how to select the right one.

What Is an Underground Water Shut-Off Valve?

An underground water shut-off valve is a valve buried below ground that allows the main water supply to a property to be turned on or off. It is usually located near:

• The property line

• The sidewalk

• The street

• A water meter pit

• A curb box

Common names include:

• Underground shut-off valve

• Curb stop valve

• Curb valve

• Curb stop

• In-ground shut-off valve

• Water main curb stop

It is operated using a curb key, a long T-shaped tool that reaches down into the curb box to open or close the valve.

What Is a Curb Stop Valve? (Most Common Type)

A curb stop valve is the most widely used underground shut-off valve. It is installed on the water service line between the municipal water main and the building.

Why it’s called a curb stop

It is usually installed close to the “curb”—the point where the city’s responsibility ends and the property owner’s begins.

What it does

• Shuts off water to a building without entering the property

• Allows city workers to disconnect service if needed

• Provides isolation for repairs

• Can be used for winterizing pipelines

How it works

A curb stop is usually a ball valve or a plug valve, controlled through a long vertical rod that aligns with a curb key inserted from the surface.

Types of Underground Water Shut-Off Valves (Complete List)

1. Curb Stop Valve (Most Common)

A valve installed underground to stop water to a property.

Features:

• Ball valve or plug design

• Quarter-turn operation

• Brass, bronze, or polymer construction

• Straight or angle body

Best for:
✔ Residential water supply
✔ Commercial service lines
✔ Property isolation

2. Stop-and-Waste Valve (with Drain Hole)

Also known as:

• Curb stop valve with drain

• Underground water shut-off valve with drain

This valve has a “waste port” that drains water from the service line when the valve is closed—ideal for cold climates.

Best for:
✔ Seasonal properties
✔ Irrigation systems
✔ Outdoor plumbing

3. Angle Curb Stop

Installed where piping changes direction.

Best for:
✔ Tight installations
✔ Meter settings

4. Straight Curb Stop

A straight-through design.

Best for:
✔ Standard service line shut-off

5. Ball Curb Stop

A modern ball-valve design that offers:

• Longer service life

• Corrosion resistance

• Smooth operation

6. “1-Inch Curb Stop” (Common Size)

Many searches involve sizing, such as:

• 1″ curb stop

• 1 inch curb stop valve

• 1″ curb stop valve with drain

Used for:
✔ High-flow residential lines
✔ Small commercial buildings

7. Underground Stop-and-Waste Valve

A variation with a drain port.

Used for:
✔ Irrigation blowout
✔ Frost protection

Comparison Table: Underground Shut-Off Valve Types