Based on the CDC figure of at least 1 gallon (about 3.8 litres) per person per day (Centers for Disease Control and Prevention (CDC)). Official sources differ, and hot climates, children, pregnant or nursing women and people who are ill need more. Pet water needs vary by animal, so ask your vet; this tool only reminds you to add some.
Sources
- Centers for Disease Control and Prevention (CDC): How to Create an Emergency Water Supply
- Ready.gov (FEMA): Water
- Swedish Civil Defence and Resilience Agency (MCF): Access to water during a crisis
- Get Prepared (Public Safety Canada): Your Emergency Preparedness Guide
- UK Government (Prepare): Get prepared for emergencies