In the event of an emergency water is of the utmost importance in any survival kit. This applies whether sheltering in place or evacuating.
The CDC provides a guide for storing emergency water and since water is JOB 1 we are curious as to whether its recommendations are followed and if not what alternate solutions people are following.
Briefly the CDC guide recommends storing 1 gallon of water per person per day for at least 3 and ideally 14 days. Water should be stored in sealable, unbreakable food-grade storage containers in a cool dark place and rotated every six months.
Here is a link to the full CDC recommendations on water storage.