How to Shut Off Water in a Plumbing Emergency

A plumbing emergency goes from manageable to catastrophic in the minutes between when water starts flowing where it should not and when you can stop it. Every Round Rock homeowner should know where four shutoffs are before an emergency happens: the main shutoff, the water heater shutoff, fixture shutoffs at toilets and sinks, and the curb stop at the property line.

Locate them this weekend. Take photos. Tape labels on each valve. The 10 minutes of preparation today will save thousands in damage someday.

The Four Shutoffs to Know

1. The Main Shutoff Valve (Inside the Home)

This valve cuts all water to your entire home. It is your most important shutoff.

Where to look:

Most Round Rock homes: garage wall, often near the water heater or pressure tank
Where the main water line enters the house from outside
Sometimes inside a utility room or laundry room
Older homes: occasionally in a closet or near the kitchen

What it looks like: Either a quarter-turn ball valve (a lever you turn 90 degrees) or a gate valve (a round handle you turn clockwise).

How to operate:

Ball valve: turn the lever perpendicular to the pipe (90 degrees). Closed.
Gate valve: turn the round handle clockwise as far as it will go. May need several full turns.

Test it once a year. Gate valves seize up if never operated — exactly when you need them most. Open and close it slowly once a year to keep it working.

2. The Curb Stop (Outside, at the Property Line)

This is the city's shutoff for the water serving your home. If your main shutoff inside is broken or you cannot reach it, the curb stop works.

Where to look: Usually in a small underground box near the street, on the same side of the house as the water meter. There may be a metal lid labeled "WATER METER" or similar.

What it looks like: A meter box with the meter inside. The shutoff valve is often a "key" type that requires a special long-handled curb-stop key (sold at hardware stores for $20-30).

Tip: If you cannot easily access this with a normal tool, call the City of Round Rock Utilities at 512-218-5555 to request shutoff in a true emergency. They can dispatch.

3. The Water Heater Shutoff

If the water heater is the source of the emergency (rupture, leak from the tank), shutting off only the heater's cold supply isolates the problem while leaving the rest of the home with water.

Where to look: The cold water line entering the top of the water heater has a shutoff valve within a few feet — usually within arm's reach above the tank.

How to operate: Same as main shutoff — quarter-turn ball valve or round-handle gate valve.

Then: Also turn off the gas (knob on the gas control to OFF) or the breaker (electric water heater).

4. Fixture Shutoffs (Toilets, Sinks, Dishwasher, Washing Machine)

Each toilet and most sinks have local shutoff valves under or behind them. Closing one of these stops water to that single fixture without affecting the rest of the home.

Toilets: Look behind and slightly below the toilet tank. There is a small valve on the supply line going into the tank. Turn clockwise to close.

Sinks: Open the cabinet under the sink. Hot and cold supply lines come up from the floor or wall — each has a small valve.

Dishwasher and washing machine: Usually shut off at separate valves nearby, sometimes color-coded.

Refrigerator water/ice maker: A small shutoff valve where the supply line comes out of the wall, usually behind the fridge.

What to Do When an Emergency Happens

The decision tree depends on the source:

Burst pipe inside the home, source unclear:

Shut off the main valve (whole house)
Open a faucet at the lowest fixture to drain the lines
Locate the burst
Call a plumber

Single fixture leaking (toilet, sink, appliance):

Shut off the fixture's local valve
Confirm flow stopped
Address at your pace

Water heater leaking from the tank:

Shut off the cold supply valve at the heater
Shut off the gas (or breaker)
Drain the tank via the drain valve if you can
Call a plumber

Water main break outside / front yard flooding:

Try the main shutoff inside first
If that doesn't stop it, the leak is upstream of the main — use the curb stop
If you cannot operate the curb stop, call the City of Round Rock Utilities for emergency dispatch
Call a plumber

What If You Cannot Find or Operate Your Main Shutoff

This is very common — homeowners often discover during the emergency that the valve is seized, painted over, behind a built-out wall, or simply not where they expected.

Plan B is the curb stop. If you cannot access that either, call the City of Round Rock Utilities Emergency line at 512-218-5555 (after-hours emergencies).

Once the emergency is resolved, replace the seized main shutoff with a working quarter-turn ball valve. This is a $150-275 plumber visit that prevents a five-figure disaster next time.

Things to Have Ready

A small emergency kit near the main shutoff:

Curb stop key (if your curb stop needs one)
Adjustable wrench
Pipe wrench
Flashlight
Bucket
Towels
Plumber's phone number (write it on the wall near the valve)

Cost: $30-50. Worth every dollar.

Teach Other Family Members

Walk every adult and older child in the home through the four shutoffs once a year. The cost of an emergency is much higher if the only person who knows where the shutoff is happens to be out of town.

After You Stop the Water

Once the water is off and the emergency is contained:

Document with photos (insurance)
Call a plumber — our emergency line is staffed 24/7
Mitigate water damage with towels, fans, and water extraction
Note the time of discovery for insurance documentation

See our burst pipe first 60 minutes guide for the broader response.

Service Area

Emergency plumbing service throughout Round Rock, Cedar Park, Pflugerville, Georgetown, and Hutto. 24/7 dispatch.