Humans are extremely good at survival. That is the reason we are the most populous species on the planet. We have come up with innovative techniques to somehow thrive even in the harshest of environments. And we still come up with very nifty tricks to survive even when nature shows its full wrath. With a good presence of mind and wits around you, you can use these tricks to survive a natural calamity too. Strap a torch to a 10 liter can of water for ambient light You can easily light up a room with this contraption when the power lines go out during a disaster.
Leaves and grass will hold it up fine until you get to safety. This applies to bicycles and cars too. But with cars, you have to cut up the tire to put the grass in.
When your buckets are all full, you can use the washbasin and bathtubs as a container for storing water.
Do NOT use your toilet bowls though.