How to keep your outdoor emergency water from freezing

Water is essential to life so it should be your top priority to keep your outdoor emergency water from freezing. Of course, indoor water storage is preferred, but it isn’t always an option. Below I will discuss some of the challenges of storing your water outdoors in the winter. I will also teach you how to keep your emergency outdoor stored water from freezing.

You don’t want your emergency water to freeze

It’s obvious that frozen water in an emergency is bad news that goes beyond the minor inconvenience it may cause in everyday life. Frozen water is a threat to your health in an emergency and can cause significant damage to your property.

How to keep your outdoor emergency water from freezing

Frozen water is a prepper’s worst nightmare in the winter

  • It is dangerous to consume frozen water. I’m sure that we have all heard the advice to avoid eating snow (especially if you read my article about finding drinkable water in the winter wilderness.) This advice also applies to your frozen water supply. If you consume ice, you will end up lowering your core body temperature. In a survival situation, that could lead to uncontrollable shivers, hypothermia, and eventual death.
  • Frozen water is a destructive force. People often think of water freezing in their ice cube trays and it doesn’t paint a picture of danger. The harsh reality is that frozen water can and will destroy whatever you are storing it in if it isn’t properly stored. When water freezes, it expands about 10%. A few common problems with frozen water are exploding water bottles, bursting pipes, and busted emergency water barrels. A busted water pipe would be annoying in everyday life, but imagine how devastating it would be in an emergency situation when you are depending on it for survival.
  • Frozen water is contaminated easily. Frozen water has a higher likelihood of contamination. This is because the expansion of water puts added stress on pipes, seals, and other aspects of your water system. Your entire emergency water supply could easily become contaminated by the tiniest crack in your system. You won’t even know that it’s contaminated until you consume it and end up sick. The frightening truth is that parasites and bacteria can lay dormant in ice then come back to life once thawed. You may not have the luxury of a stove or even a basic survival fire and that will limit your chances of purifying the block of ice that used to be your emergency water supply.
  • Thawing ice is a huge waste of energy. When you need to use your emergency water supply, chances are that both inside and outside of your home will be cold. Any method of melting the ice will require significant amounts of energy. Don’t waste it.

How to keep your outdoor emergency water from freezing

Indoor water storage is ideal, but I wouldn’t be a very good prepper if I didn’t also offer solutions for outdoor water storage. I keep a significant portion of my emergency water stored outdoors in large tanks. I do this simply because there isn’t a lot of extra space in my home and I still want to have a lot of water just in case.

There are some anti-freezing methods that require more planning and cost more money, but can yield better results. I also have options for you if you have limited time, space, and money.

Method #1 Store your water underground

First, find out the depth of the frost line in your area. This is the depth at which the ground is expected to freeze. Home builders regularly use this information while planning the construction of the home’s foundation.

Acquire this information at your local building department or by visiting this website to get a general idea of where the frost depth is in your area. Once you know that depth, you can store your water below that level so it will be protected from freezing.

Underground water storage ideas (below the frost line):

  • Underground water storage tank
  • Airtight containers of water (55 gallon drums)
  • Large PVC pipes capped at both ends that are full of water

No matter what container you choose to use, make sure that the top of your water container is below the frost depth. Careful measuring is crucial because you don’t want any part of it peeking above ground. When in doubt, bury it deeper than you think you need to.

You won’t be taking up precious indoor space with your water supply safely stored underground. Additionally, it will be hidden from looters. The downside is that your water won’t be easy to access or portable. You will also need to make sure that it is in close proximity to your shelter or build a shelter nearby.

Pro Tip: A larger tank is better since larger masses of water take longer to freeze.

Method #2 Use steel tanks to absorb heat

Even if you can’t bury your water tank underground, there are still ways to prevent your emergency water from freezing when it’s stored above ground. For example, large, steel tanks can absorb heat from the sun and prevent freezing.

  • Make sure that your tank has maximum sun exposure. The more sunlight exposure on your water tank, the better. Make sure that it is out in the open and not shaded. Southern exposure is best for those in the United States or other countries in the Northern hemisphere.
  • Paint the kettle (water tank) black. Black absorbs light (energy) while light colors like white will reflect it. Painting your water tank black will help it absorb the maximum amount of warmth from the sun.
  • Insulate your water tank. Wrap your water tank with insulation from your local home improvement store. In a pinch you can use foam, newspapers (if they can be kept dry), or blankets. Any insulation will help the container retain the heat it has collected.
  • Position your tank to touch the outside of your home. Only do this if it is structurally safe. Remember that water weighs a lot -over 8 pounds per gallon. You can produce a heat sink that will allow your tank to absorb some of the warmth from the wall of your home by firmly mounting your tank against an outside wall.

If you don’t get a lot of sun then this method will be less effective for you.

Method #3 Use a greenhouse

Greenhouses are much warmer inside than the outside even in the winter. You can even increase the temperature by keeping a compost pile inside of the greenhouse. Did you know that compost piles can reach up to 170 °F? Even if the compost doesn’t get very hot in the winter time, the smallest temperature increase can keep a large water tank warm enough to prevent freezing.

The downside of this method is that vermin and rodents with be attracted to the warmth and the compost itself.

Method #4 Store water in your car

It’s a no-brainer that your Bug Out Bag in your vehicle should include a personal water supply. You should keep extra bottles of water in the cab of your car, not the trunk. When you start your car, the water will get warm and the cab will retain heat for awhile which will decrease the chance of frozen water. This is especially true if you sleep in your car because your body heat will keep your water supply from freezing.

Pro tip: For the best results, store your water on the seats rather than the floor.

Method #5 Store water in a cooler

I’m very fond of storing my water supply in a regular camping cooler. The properties that keep my beer frosty and cold in the summer will keep my emergency water supply from freezing in the winter. The key to success is to only open the cooler when absolutely necessary.

Recharge the warm air inside by opening your cooler near a fire. If your cooler has a metal lining, you can place a heated stone from your fire inside to prevent your water from freezing.

Should you use water additives?

I have never found a safe or reliable additive that will prevent freezing. This is another reason why I wanted to move to a warm place (Hawai’i). I was tired of my water freezing in my car.

The biggest issue with using an additive to prevent your water from freezing is that you’ll eventually have to drink it. Or you will have to figure out a way to remove the additive before drinking it.

  • Salt. Your drinking water is not going to taste very good if you add enough salt to prevent freezing. Also, the amount of salt you would need to add can be dangerous. As a whole, every prepper knows that drinking salt water is never a good option. Not to mention it can cause dehydration and too much sodium can lead to heart problems and kidney issues.
  • Sugar. Some preppers suggest using sugar based additives, but we can debunk this myth by looking at popsicles. A popsicle is literally colored sugar water and it has no trouble freezing.
  • Alcohol. I have heard of preppers spiking their water to prevent freezing, but I’m unwilling to try this method. Alcohol can impair your decision making skills and it has lasting effects on your body that can lead to health issues. Consuming alcohol is also an invitation for hypothermia because alcohol causes blood vessels near your skin to dilate. That moves blood and heat away from your core which lowers your body’s temperature.

I think that additives are risky and not worth the risk. I would rather use a different method that doesn’t cause kidney damage and dehydration.


Water freezes from the top down so you should store your personal water containers (bottles, canteens, thermoses) upside down, with the lid on the bottom.

I hope that you learned something new today. What challenges are you having with your water storage? Have you figured out ways to prevent your water from freezing? Comment below to share!