What does the future hold for humanity? The collapse of lawful society? A multi-generational natural disaster? Homeland invasion? The Four Horsemen of the Apocalypse? Hopefully, none of these. But being prepared for life-threatening situations can drastically improve our odds for survival.

Many of us living in urban and suburban areas wouldn’t last long if our faucets ran dry and our store shelves were stripped bare. The failed response of the Department of Homeland Security and the Federal Emergency Management Agency (FEMA) during the immediate aftermath of Hurricane Katrina affirms that we cannot depend wholly on government during our time of need.

We buy auto insurance to protect ourselves against losses incurred by traffic collisions. Investing in these policies doesn’t mean we’re fatalistic or that we’re wishing for an accident to happen—it’s just in case. Shouldn’t the same foresight be applied to more vital needs like food and water?

According to the SE Wisconsin Emergency Preparedness Meetup Group, survivalism is approached by its adherents in different ways, depending on their beliefs, circumstances and particular concerns for the future. An essential principle of emergency preparedness is food and water storage. There is a great deal of literature on the subject, though instructions regarding how much food and water should be stored and for how long vary according to different sources.

It is generally believed the human body can survive a maximum of three days without the intake of water, although it depends on a number of factors, including a person’s health and environment. FEMA suggests having at least a three-day supply of water, storing at least one gallon of water per person per day.

Karen Urbanek, from Nature’s Garden, a whole-food grocery and organic marketplace that specializes in food and water storage, recommends a two-week supply, or 14 gallons of water per adult.

An easy way to store water is to simply purchase commercially bottled water, keep it in its original container and not open it until you need it. You can also store water in food-grade water storage containers or clean plastic, soft-drink bottles. Bottled water can be used indefinitely if stored properly away from direct sunlight and extreme temperatures, though changing it yearly will prevent it from tasting like the packaging.

We can survive far longer without food than we can without water, but the state of weakness caused by undernourishment can seriously hinder a human being’s will and ability to fight for life. FEMA recommends storing at least a three-day supply of nonperishable food that requires no refrigeration or preparation and little or no water. Canned juices, milk, soup, meats, fruits and vegetables are compact and lightweight and have a relatively long shelf-life. Just don’t forget the can opener! Simply donate the canned items when they are close to expiring and buy a new supply.

Other storage suggestions include vitamins, high-energy foods such as peanut butter and trail mix and staples like sugar, salt and pepper. Include comfort foods like instant coffee, hard candy and cookies to improve morale.

While FEMA’s food storage principles are intended for brief natural disasters, Urbanek’s are more long-term in scope. She recommends the following one-year storage amount per adult: grains: 275 pounds; legumes: 100 pounds; honey: 60 pounds; oil: 10 quarts; sea salt: 8 pounds.

Mylar bags are FDA-approved structures that are great for long-term food storage. The thick layers of plastic and aluminum have a high puncture resistance and help prevent or greatly reduce light from deteriorating the contents, oxygen absorption that causes rancidity, moisture absorption that causes organism growth and the permeation of smells from the surrounding storage area. Used with oxygen absorbers, plastic food-storage buckets and #10 cans also store food well.

It’s upsetting to think that the state of the world may worsen to a point where we would have to depend on a personal cache of food and water to survive. But preparing for the worst doesn’t make it so. It makes you smart. Better safe than sorry.