After a disaster, if you hear reports of broken water or sewage lines, or if officials advise you of a water problem, you may want to shut off your water to prevent tainted water from getting into your home. Turning off your house valve also prevents a broken water line from draining your toilet tanks and hot water heater.

Note that the house valve is not the valve in the cement box by the street—that valve can only be turned off by the water company. The house valve is generally located outside your home near a hose bib.

Here are some tips for managing water in a disaster.

• Never ration water unless authorities recommend doing so, and never drink less than a quart of water a day.
• Don’t drink cloudy or otherwise contaminated water from a faucet, stream, or pond without treating it first, unless you are at risk of dehydration.
• Don’t drink soda or alcohol instead of water.
• To use the water in your pipes after your water is turned off, completely open the lowest faucet in your home and capture water as it trickles out.
• To use the water in your hot-water tank, turn off the electricity and/or gas, open the drain at the bottom of the tank, turn off the water intake valve, and turn on the hot water faucet. Be sure to refill the tank before turning it back on.
• You can also get drinkable water from melted ice, and liquids from canned goods.
• Never drink water from radiators, hot water boilers, water beds, toilets, pools, or spas.