How to find and test your main water shutoff valve

Updated November 11, 2026. By Landen Chu, Co-founder of OakTend. How we research

Finding the house valve that shuts off the water to your whole house, then turning it off and back on once so you know it works before a burst pipe or a slab leak.

How often: Do it when you move in, then once a year. Alameda County Water District, a Northern California provider, says exercising the house valve routinely helps keep it from corroding.
What you need: A tag or label for the valve, Work gloves

Why it matters

Irvine Ranch Water District says the house valve typically controls the entire water supply to your house. Ready.gov warns that a valve may be rusted open or may not close all the way. Better to find that out now than during a burst pipe. Closing this valve is also how you tell a leak inside the house from one in the yard line; our slab leak repair guide explains that check.

Steps

Look where the water line enters the house. In many Orange County homes it is outside at the front, next to a hose bib (an outdoor faucet). Irvine Ranch Water District says the house valve is usually at the hose bib, and East Orange County Water District says to look where the line enters the building.
Pick a time when nobody needs water, and make sure no faucets, the dishwasher or the washing machine are running.
Close the valve. A round wheel handle turns clockwise until it stops. For a lever, Irvine Ranch Water District says it is open when it lines up with the hose bib and closed when it points away from it.
Open a faucet inside the house. The flow should slow and stop. A steady trickle that keeps going means the valve does not close all the way.
Open the valve fully again: counterclockwise for a wheel, back in line with the hose bib for a lever. Leave the inside faucet open until the water runs steadily, then close it.
Tag the valve so it is easy to find, and show everyone at home where it is. Ready.gov recommends both.

The gas meter has its own shutoff, but you only close that one on signs of a leak. See how to shut off gas after an earthquake.

When to call a pro

If the valve will not turn by hand, will not close all the way or drips at the handle, stop and call a licensed plumber to replace it rather than forcing it. If you cannot find a house valve at all, a plumber can add one; Garden Grove's code, for one, makes the customer supply the valve between the meter and the house. When the plumber needs the meter turned off first, call your water provider: Garden Grove's Water Services Division does it during business hours at (714) 741-5395.

Safety

Leave the meter box at the curb alone unless your provider says otherwise. Garden Grove says only city staff may operate city shut-off valves except in an extreme emergency, and makes whoever damages one pay for the repair. Ready.gov says the street valve is extremely difficult to turn and needs a special tool. Some providers do put a customer valve in the box: Irvine Ranch Water District's sits on the side closest to your home and turns by hand, but even so, call your provider first. After a disaster, Ready.gov says to shut the house valve until officials say the water is safe to drink; closing it also keeps the water in your water heater and toilet tanks from draining away.

Go deeper

This is general information, not professional advice. Your equipment's manual comes first when it says something different.

Sources

Irvine Ranch Water District: water leaks
A house valve is part of the private plumbing and typically controls the entire water supply to your house; it is usually located at the hose bib; it is on when parallel with the hose bib and off when pointing away from it; turn counterclockwise to open fully; the customer valve is in the meter box on the side closest to your home and should turn easily by hand.
City of Garden Grove: shut-off valves
City water shut-off valves are not to be operated by anyone besides city personnel except in extreme emergencies; whoever damages one pays for the repair or replacement; customers must provide their own valves between the meter and the first outlet (Municipal Code 14.20.050); call the Water Services Division at (714) 741-5395 during business hours to have staff operate a valve.
East Orange County Water District: about your water
Close the main line valve clockwise where the line enters the building.
City of Huntington Beach: water and sewer
For after-hours water emergencies, such as water main breaks or loss of water service, call the Police Department at (714) 960-8825.
Ready.gov: Safety skills, know how to shut off utilities
Find the shut-off valve for the main water line that enters your house and tag it; make sure everyone knows where it is; make sure you can shut it off completely; a valve may be rusted open or not close all the way, and if so replace it; shut off the water until authorities say it is safe to drink; shutting the main house valve traps the water in the water heater and toilet tanks; this is not the street valve in the cement box at the curb, which is extremely difficult to turn and requires a special tool.
Alameda County Water District: Get to know your house valve (December 2025 flyer)
The house valve is typically near the hose bib in the front of the home; turn it on and off routinely to exercise the valve, helping prevent corrosion; the homeowner operates and maintains the house valve.

More water heater and plumbing

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