If you do nothing else, you need to store water for your family, at least 3 weeks worth, not the commonly suggested 3 days worth. When floods, earthquakes, or wildfires destroy the water processing, purification, and distribution infrastructure,
it is not going to be fixed in 72 hours.
Storing your water in the home out of daylight in gallon jugs will work well for most people. It is much easier to store modular gallons like the Crystal Geyser variety of square stackable jugs than in 5 gallon carboys. Many people cannot lift and invert a 5 gallon jug of water safely on a water stand.
Buy and store your water in gallons, out of direct sunlight or heat sources (the bottom of closets or cupboards) and buy a single 5 gallon jug and fill it from your gallon jugs with a kitchen funnel, to use as your dispenser with a hand operated pump shown at right (available at Home Depot $9.99 Walmart, Amazon and other outlets.)
These type of pumps are available at Walmart, Home Depot, Amazon and many other places. The "bathrub liner tanks" are not a good idea as they are hard to manage and keep clean and if they are polluted with a spider or a fly - that makes it require boiling/purification before being able to use it for consumption.
WATER, WATER, WATER
A lot of folks do not realize that the majority of all drinking water supplies serving the Bay Area will be out of commission if the Hayward Fault ruptures the Hetch-Hetchy line through the Diablo Range to the San Mateo terminus. While California's OES and FEMA will be working feverishly to get water back online - it is a safe guess that it will be a while before they succeed.
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Water, Water, Water and More Water
Most Emergency Preparedness planning agencies suggest that people keep enough water on hand for each person living in the household for at least 3 gal. per person per day, for 7 to 10 days—the time most federal and local disaster planners expect to be potentially unable to guarantee provision of safe drinking water from your taps at home.
How much water do you use in your average daily routine? Have you measured it? Track it. Write it down. More on water storage ideas.
Example: 2 adults living in your home.
2 adults x 3 gals per day = 6gals per day x 18 days = 108 gals of “human” usage of water to store.