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How to Make an Emergency Water Supply for Your Home

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This guide will break down your options for making an emergency backup water supply for your home.

This guide will break down your options for making an emergency backup water supply for your home.

Why Your Home Needs a Backup Emergency Water Source

In survival training school, one learns that humans can survive for weeks, even months, without food yet only a few days without water. Gandhi, for one, survived a 21-day hunger strike but did not refuse water. Most humans can only survive for 3–5 days without drinking water or being given intravenous fluid.

If another pandemic, riot, chemical, or dirty bomb situation was to cut off or render poisonous the water supply in your city, how long could you and your family live? The answer depends on what reserves of water you have on hand and your ability to replenish that supply.

Your Water Heater as Source of Emergency Water Supply

If your water supply has been shut off and if there is no other source of water available, your tank-type water heater (if you have one) holds anywhere from 20–60 gallons of potable water. You will first need to locate and shut off the breaker (if it is electric) or turn it off and shut off the gas supply (if it is gas).

Then you should shut off the outlet valve, which is typically located on the top of the unit. Most tank-type water heaters have a drain valve, located at the base of the unit, which looks like a typical yard faucet, only shorter.

After the water has cooled off for a few hours, you may attach a garden hose at the base and run that hose out to where it is a few feet lower than the tank. If you have a hose-end spray nozzle, you can attach it to the end to make a faucet so that you can fill containers.

Water heaters build up sediment at the bottom of the tank, so allow the water to run until it runs mostly clear. You can save the first sediment-filled water in a separate container and allow the sediment to settle out. After settling it may be safe to drink, however, this first-drained water should probably be used for uses other than consumption due to its high mineral content.

Keep in mind that you will need to fill the tank again when your water comes back on. To do this, first close the drain valve, slowly open the hot water out valve on top. Then open a bathroom or kitchen faucet for several minutes to let the air escape from the tank as it fills again with fresh water. Failure to do so may result in an explosion, so don't forget to fill the tank again before turning on the gas, or the breaker if electric!

Bathtub and Other Reservoirs as Emergency Water Reservoir

If you feel that your water supply is in danger of being shut off, fill every bathtub that you have. A typical bathtub holds about 80 gallons of water, or a 20-day supply of drinking water for a family of four.

Protect your water supply by covering the tub with plastic sheeting or a shower curtain, and check it for the first couple of hours to make sure that the drain plug is not leaking. If the drain plug is leaking, chewing gum can be used to press in around the edges of the drain plug to seal it. Extra capacity can also be gained if you are able to plug the overflow, just don't forget to unplug it when the water comes back on.

If you have a kid's pool, and your water supply is still on, consider filling it up inside the garage and covering it with plastic sheeting. (Beware of creating a drowning hazard for children or pets.) Fill any other containers that you can, such as ice chests, pots, pans, etc., and make sure large containers are safely secured from children who may fall in.

A good suburban survival idea is to purchase a couple of food-grade barrels filled with water and stored away in the garage. Always avoid re-using ordinary food containers to store water, since the plastic may leach harmful chemicals into water over time. Use only BPA-free water storage jugs, which are available at outdoor stores.

How Much Bleach Should You Treat Your Water With?

Please note that there are several concentrations of bleach available.

  • For 5.25% regular sodium hypochlorite bleach (no scented kind) the dosing is 3/4 teaspoon per 10 gallons of water.
  • For the stronger 8.25% bleach, the dosing is 1/2 teaspoon per 10 gallons of water.

There should be no need to treat city water stored in closed containers or in a water heater since it has already been chlorinated. Treating water with sodium hypochlorite (check the label first) bleach can be used for water that may have contaminants, such as rainwater that you have collected from your roof.

Here is a diagram of a typical rainwater collection system. Yours in a suburban setting may use a much smaller tank if there are HOA restrictions.

Here is a diagram of a typical rainwater collection system. Yours in a suburban setting may use a much smaller tank if there are HOA restrictions.

Rainwater Collection Systems

A rainwater collection system is always a good investment and can be an excellent source of emergency water. There are many kinds of rainwater harvesting systems, however, for the average suburban prepper, the options may be limited by homeowner association rules or space.

If you are unable to install a 200-gallon or larger plastic tank to your gutter system, a smaller barrel-type catchment tank can give you an extra 40 gallons of water for an investment of around $100. Food grade barrels are often found for sale on sites such as Craigslist and square 275-gallon "totes" or food-grade tanks also make excellent rainwater cisterns.

I personally have a 275-gallon food grade tote hooked up to my downspout, using a "first flush" type pre-filter and screen system. To make it more attractive I have attached cedar fence pickets around its perimeter using 2" self-tapping metal screws and let ivy crawl over it.

A basic rainwater collection system should include a first flush diverter, which is a device to allow the first rainfall that comes to be diverted instead of contaminating the tank. If you don't have a first flush diverter at least have a screening system in place to keep out leaves and other debris.

Other Emergency Water Sources

Be extremely cautious when considering spas or pools as sources of drinking water. The amount of chlorine found in spas and pools may be far too high for human consumption. Use spa or pool water in an emergency only if you have a survival-grade water filtration system capable of removing chlorine and other chemicals.

If you don't have a rainwater collection system set up, and there is rainfall predicted, try and locate any containers that you may find and place them under downspouts and collect water when you can. Although this water may look clean, due to things such as bird droppings you should treat it first.

If your city water supply has been shut off, you may be able to squeeze a few gallons out of your home's pipes, by locating the lowest faucet in the house. See if there is still water coming from faucets outside or in the basement, and fill any clean containers that you have from them.

You May Have to Turn Off Your Home Water Supply

If your city water supply has been compromised you may want to shut off your home's main water supply valve at the street. During an earthquake, for example, water lines can become severed and raw sewage may seep back into them as the pressure falls. Check with your local water utility's website or call them if you are concerned about the safety of your drinking water following a disaster.

Water Purification Tablets

It is not generally considered safe to use iodine-type water treatment tablets on a long-term basis. The safest way to treat water is to filter it with a survival-type water filter made to remove pathogens. Chlorine-based water tablets are considered safer for long-term use, which is why most municipal water supplies in North America are chlorinated.

Finally, chlorine bleach emergency water treatments, including sodium hypochlorite and chlorine dioxide, are still poisons and must be used in proper doses to avoid sickness or death.

How to Build a Rainwater Collection System

This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.

© 2020 Nolen Hart