How to Shut Off Your Water in an Emergency

The time to find your main water shutoff is now, while nothing is wrong. When a supply line lets go, the water does not wait while you search the garage with a flashlight, and the damage is a direct function of how many minutes it runs.

It takes five minutes to locate it, label it and confirm it turns. That is the whole task.

Where It Is in a Valley Home

Most Las Vegas homes have two options.

The house shutoff is the one you want. In valley construction it is commonly in the garage, often near the water heater or on the wall shared with the front of the house, and sometimes on an exterior wall in a small access box. It controls the whole house.

The meter valve sits at the street in a concrete or plastic box, usually near the sidewalk. This is the utility's, and it is the backup if the house shutoff fails or cannot be found.

Newer homes usually have a clearly accessible house shutoff. Older ones sometimes do not, which is itself worth fixing before it matters.

The Two Valve Types

Ball valve. A lever handle. A quarter turn, so the handle ends up across the pipe rather than along it. Fast and reliable.

Gate valve. A round wheel handle. Turn clockwise, several full rotations, until it stops. These are the ones that fail. A gate valve untouched for fifteen years can seize, or the stem can shear, or it can close most of the way but not fully.

If yours is a gate valve, exercising it once or twice a year keeps it working. If it will not move with reasonable force, stop rather than forcing it, and have it replaced. A valve that snaps during an emergency turns one problem into two.

Do This Today

1. Find it. Walk the garage and the exterior wall. Look near the water heater and near the front hose bibb.
2. Turn it off and back on. Confirm it actually works, and confirm the water stops. Do this now, not during a flood.
3. Label it. A tag reading MAIN WATER SHUTOFF. Whoever is home during the emergency may not be you.
4. Clear access to it. Boxes, shelving and storage stacked in front of it cost time when time is what matters.
5. Tell the household. Everyone old enough should know where it is and which way it turns.
6. Find the meter box too, and know whether the lid lifts without a special key.

The Other Shutoffs

Water heater. A valve on the cold inlet at the top. Closing it stops the supply to the heater without shutting the house down, which is what you want for a leaking heater. Our post on a leaking water heater covers the rest of that situation.

Fixture stops. Small valves under sinks and behind toilets. For a fixture-level leak, this is the right valve and it isolates one thing rather than everything.

Outside. Hose bibbs and irrigation have their own valves, and a failed irrigation line can waste a large amount of water without ever entering the house.

In the First Minutes

Shut off the main. Then open the lowest faucets in the house, and outside, to drain the pressure and the standing water in the lines, which reduces how much continues to escape.

If water is near electrical outlets, panels or appliances, cut power to the affected area at the breaker before going into standing water.

Then call a plumber, and if the damage is significant, call your insurer. Photograph everything before cleanup begins.

For a gas leak the procedure is different and more urgent: leave immediately, touch nothing electrical, and call 911 and Southwest Gas from outside. Our post on gas line leak signs covers it.

Leaving Town

Shut the main off if the house will be empty for more than a few days. A supply line failing while nobody is home is the scenario behind most of the severe water damage claims plumbers see, and it costs nothing to prevent.

If irrigation needs to run, isolate the house supply rather than the whole system.

Practical Takeaways

Find it, turn it, label it, clear the space around it, and make sure someone else in the house knows. Replace a seized gate valve before you need it. Shut off the main when you travel.

Talk to a Licensed Plumber

American Brothers Plumbing handles emergency plumbing and leak detection across Las Vegas, Henderson, Summerlin and the surrounding valley. Call (702) 704-1776.