Water is one of the least glamorous preparedness purchases and among the most useful.
Use a household calculation
Count residents, decide how many days you are planning for, and multiply by the daily allowance. Federal guidance gives a baseline of two litres per person per day. Ontario recommends four litres per person per day for drinking, preparation and hygiene. For a household of four planning for three days at Ontario's figure, that is 48 litres.
Choose storage over gimmicks
A mix of sealed bottles and food-grade containers can be easier to rotate than one enormous tank. Keep water accessible, protected from contaminants and stored as directed on packaging. Label when you filled reusable containers. Do not rely solely on a filter to produce clean water from an unknown contaminated source.
Keep your water plan simple
Identify how water will be carried during an evacuation, not just stored in a basement. Check local boil-water notices and follow public-health guidance for treatment rather than assuming a camping filter removes every risk.