There are purchased water options that have 5, 20 and even 50-year shelf lives. If evacuation isn’t an annual occurrence for you, it’s better to purchase long shelf-life emergency water than the water you see at the grocery store. The issue with your average bottle of water is that the container is a low-grade plastic not designed to last for years on end. Water itself is eternal – it’s the plastic that breaks down over time, which is why you will find an expiration date on any water that you buy at the store. The most cost-effective and user-friendly option for most people is to store tap water in a container deliberately designed for long-term storage. This is especially the case for households of three or more people.