Store an adequate amount of water for your needs
Clean water will be an important resource after a major disaster, and perhaps the most important one since it is essential to staying healthy. While a person can survive weeks without food, one can only survive a few days without water. One of the most important things that you can do to right now to prepare for a disaster is to store an adequate amount of water. To have enough water for drinking, cooking, cleaning wounds, and personal hygiene, you should store at least one gallon per person, per day for at least a two week period, and don’t forget water for your pets!

You can purchase food-grade water storage containers from surplus or camping supply stores, or reuse containers made from glass and plastic jugs previously used for soft drinks or bottled water. Previously used containers must be washed with soap and hot water and rinsed thoroughly prior to using.  Never use containers that held pesticides, oils, solvents, or other toxic substances. Store your water in a cool, dry place, safe from flooding or freezing. Use or discard stored water every 6 months, and replace it with a fresh supply. If reusing containers, add 1 or 2 drops of bleach per gallon before storing. More information on the storage and treatment of emergency drinking water can be found in this brochure from the Washington State Department of Health's Office of Drinking Water.

Know how to locate and turn off your water supply
Find your master water valve and learn how to shut it off during emergencies. This valve is usually located somewhere inside the home where the water line enters the house from the water meter, usually in a basement or garage. Mark the master valve with a tag or paint it with a bright color so you can find it quickly during an emergency. Show other family members where the master valve is located and teach them how to use it. You should also find your water meter (usually outside at the property corner near the street) and practice shutting it off in advance of an emergency event.

Identify alternate sources of water in and around your home
Possible alternate sources of water and around your home include your hot water tank, the pipes inside your home, water from ice cube trays, rainwater, streams, ponds or lakes. Please take precautions when using alternate sources of water and follow guidelines from the American Red Cross and the Washington State Department of Health.

Don’t forget that what goes in, must go out!
After a major disaster, you may need to live without working toilets for an extended period of time. Learn how to do this safely, because diseases can spread when human waste is not handled and stored safely. Read the Emergency Toilet Guidebook from the Regional Disaster Preparedness Organization (RDPO) to learn more about how to stay healthy after a disaster.

You can find general emergency preparedness tips at King County's "Make it Through" website.