Disasters can disrupt your community drinking water distribution system. Since you will need water within a couple of days, you need to know where to find an emergency source of water and how to make it safe to drink.
Additional water is needed for brushing teeth, bathing, and cleaning cooking utensils.
Store as much water as you have space for, but a three days supply is considered to be a minimum amount. You can store tap water in clean beverage bottles so long as you have an airtight seal. However, do not use containers that have held fluids or materials that were not drinkable or edible. Water can be purchased at a market in soft plastic containers or from water retailers in large 5 gallon hard plastic bottles. To ensure your hot water heater survives an earthquake, secure it to the wall with metal strapping and heavy bolts.