Learn to Shut off the Main Water Valve

When there is a water emergency, it is sometimes necessary to shut off the water supply to your house. Here's how:

  1. Look for the main valve where the water supply enters your house (usually in the basement) or in a concrete box near the street.
  2. If the valve is outside your house, lift the cover with a large screwdriver.
  3. Then, use a pipe or crescent wrench to turn off the water. (Mark the shut-off valve with fluorescent paint or tape so you can find it in the dark.)
  4. Drain all water from the system, including your hot water heater, if you must evacuate when the weather is cold.
Photo: someone turning the main water valve in their home.

Prepare an Emergency Water Supply

Unopened commercially bottled water is the safest and most reliable emergency water supply.

  • Store at least 1 gallon of water per day for each person and each pet. You should consider storing more water than this for hot climates, for pregnant women, and for persons who are sick.
  • Store at least a 3-day supply of water for each person and each pet (try to store a 2-week supply if possible).
  • Observe the expiration date for store-bought water; replace other stored water every six months.
  • Store unopened, commercially-bottled water in a cool, dry area that is not exposed to direct sunlight until the expiration date that is indicated on the bottles.
  • Store a bottle of unscented liquid household chlorine bleach to use for general cleaning and sanitizing. Please see below for the proper way to disinfect your water storage container.
Photo: gallons of bottled water

Help Avoid Emergencies

Always report broken or damaged water lines to Prince William Water immediately at (703) 335-7982.

Storing Tap Water

Have a Plan