How to find and tag the main water shutoff
The main water shutoff valve sits where the supply line enters your house, often low on a basement wall facing the street, in a crawl space, or in the garage near the water heater. Close it once to prove it stops the water, then tag it so anyone can find it fast.
Where is the main water shutoff valve?
Water and freezing damage made up about 20% to 29% of homeowners insurance losses each year from 2019 to 2023, and the average claim was about $15,400, according to the Insurance Information Institute. Knowing this valve is the cheapest protection you have.
Think about where the water comes from. Your meter or street connection is usually on the street side of the house, so the line tends to enter there, before it branches off to anything else.
| House type | Where to look first |
|---|---|
| Basement | Low on the wall facing the street |
| Crawl space | Near the foundation, where the line comes in |
| Slab, no basement | Garage, often near the water heater, or a utility room |
| Townhome or condo | A utility or mechanical closet |
| Older or remodeled house | Behind an access panel |
| Warm climate | Outside near the meter, sometimes in a covered box |
You may also find a stop-and-waste or globe-style valve in older construction. It has a round handle like a gate valve but a different body shape.
There's usually a second valve at the street, called the curb stop. Treat that as a backup. Ready.gov says to use the house valve, because closing the street valve lets gravity drain your water heater and toilet tanks, and it's hard to turn and needs a special tool. Rules on who may use it vary by water provider, so call yours before you touch it.
How to turn off water to the house and test the valve
- Trace the line
Start at the wall nearest the street or water meter and look for the largest pipe coming in. The valve sits before any branches.
- Read the handle
A round wheel is usually a gate valve, common in older homes. A straight lever is a ball valve, more common in newer ones.
- Check its condition
Look for heavy crust, stem drips or a bent handle. Set out a bucket and towels before you turn anything.
- Close it
Turn a wheel clockwise slowly until it stops. Turn a lever 90 degrees so it sits across the pipe.
- Prove it worked
Open a faucet on the lowest floor. The flow should taper off and stop.
- Reopen it
Open the valve fully. Back a gate valve off a quarter turn so it doesn't seize in the open position.
- Tag it and tell people
Hang the tag, walk every adult to the valve, and put a reminder on your calendar to test it once or twice a year.
Tag the main water shutoff valve so anyone can find it
Tie a bright tag to the valve with one line on it: main water, turn clockwise, or main water, lever across pipe. Ready.gov recommends tagging it and making sure everyone in the house knows where it is.
Clear what's stacked in front of it, and keep a flashlight within reach if it's in a crawl space. Take a photo that shows the valve and something recognizable beside it, then share it with everyone in the house, plus any house-sitter.
Water shutoff valve stuck or leaking? What to do next
A stuck wheel is common on old gate valves. Roto-Rooter warns against forcing it, because old valves can break. In a real emergency, a wrench or pliers can give you grip, but call a plumber right after. On a calm day, stop as soon as it resists.
If the valve turns but a faucet keeps running strongly, it isn't sealing. Ready.gov says a valve that's rusted open or doesn't close fully should be replaced. Plumbers often fit a full-port ball valve, which closes in a quarter turn. One guide puts the part at about $20 to $100 and the full job at about $200 to $700, depending on access and pipe material. After-hours calls cost more.
If you can't find the valve at all, call your water utility or a licensed plumber. Until you know where it is, keep the utility's emergency number on your phone, because it's your only way to stop a leak.
What homeowners say about how to find the main water shutoff
Test the city-side valve too, not just the one in the house. One owner found the stem on the street valve had snapped off its lever, so it would have done nothing in a flood. The city replaced it for free. After any work on the supply line, run an outdoor hose first to flush out grit. Flushing a toilet first clogged one owner's toilet fill valve with small rocks. (Reddit)
Curb keys don't all fit. Meter-box lids and slot angles vary, and one owner returned two keys before finding one that fit. Buy it now and try it on your own box. Owners in four threads call it a must-have before you need it. One used theirs the week after buying it, when a water heater burst in the attic. (Reddit)
If your only shutoff is at the meter box, open the lid now. Some lids are held by a five-sided bolt that normal sockets won't fit, and you don't want to find that out during a flood. Also find the lowest faucet in the house, so you can drain the pipes once the water is off. (Reddit)
Test the small shutoffs under every sink and behind every toilet too, not only the main. If your shutoff is in a meter box in the ground, owners in the South use a T-handle meter key instead of reaching in by hand, because black widows like those boxes. (Reddit)
Turn the main valve now, slowly, on a calm day, not for the first time during a leak. Valves that haven't moved in years often stick, won't fully reopen or start dripping at the stem. If yours fights you, have a plumber swap it for a full-port ball valve while nothing is flooding. (Hacker News, DIY Stack Exchange)
Find out whether there is also a street or meter shutoff and what tool it takes (often a long 'curb key'). Owners in cold climates say that valve is what saves the house when a frozen pipe bursts indoors. (DIY Stack Exchange)
Where owners disagree: Several owners warn against turning the city's curb valve yourself. Old street valves can break, some cities don't allow it, and the owner may be billed for the repair. Others reply that many slab homes have no shutoff inside at all, only at the curb. The fix most agree on: if you only have a curb valve, have a plumber add a shutoff on the house side instead of relying on a key. (Reddit)
Main water shutoff valve questions
Which way do you turn a main water shutoff valve?
Turn a round wheel clockwise until it stops. Turn a lever a quarter turn so it sits across the pipe, which means closed.
Can I shut off water at the street myself?
It depends on your water provider, so call and ask. The curb stop is often treated as utility equipment, it needs a special key, and Ready.gov advises using the house valve whenever you can.
What if my house doesn't seem to have a main shutoff?
Call your water utility or a licensed plumber to help you find it. If the only working shutoff is outside, ask a plumber about adding a valve inside the house.
Sources: Insurance Information Institute, Ready.gov, inspectandtest.net, azure.rotorooter.com
General guidance for U.S. homes, not professional advice. For gas, electrical and structural work, call a licensed pro.