While you do it rather rarely, shutting off your water is relatively simple to do. But when done, it’s most often done in an emergency. So knowing how to do it correctly and quickly can be important.

Teenagers and adults in your household should know where the water valves are and how to turn them off. They should have identifying tags and your piping can be painted a distinctive color to help find them. For large houses, especially with several bathrooms, a valve chart may be used to help locate individual valves. Valve tags may be available from plumbing dealers; many plumbers are glad to offer a tagging service to current and prospective customers.

The most important valve, obviously, is the main shut-off valve for the entire plumbing system. It’s generally located on the house side of the water meter and usually has a wheel-like handle. Because it is used so rarely, once or twice a year you

should put a few drops of oil around the valve handle to prevent it sticking from corrosion. Still, you likely will need a wrench to turn it.

But before closing the main valve, check the valve body for a small drain hole or a compression stop with a cap nut covering the drain hole; in either case, close this drain hole before shutting off the water to prevent water from spurting out. If there is no other way to close the drain hole, drive a small wooden peg into it and keep it there until all the water drains out from elsewhere in the system.

In addition to the main shut-off valve at the meter, the well-plumbed house will have shutoff valves on branch lines leading to individual and groups of fixtures as well as equipment such as water heaters and softeners, washing machines and pipes feeding outdoor watering faucets. Separate shut-off valves often are installed next to individual fixtures.