Tips for How to Store (and Conserve) Water

Table of Contents How much emergency water do I need?How do I store my emergency water?Small containersWhere do I store my emergency water?What water storage mistakes should I avoid?How do I keep my emergency water supply potable?HeatChemicalsFiltersUltraviolet lightSmart,… Read More

Side image how to store water

People in developed nations often take their infrastructure for granted. For example, turn on a tap, flush a toilet, or aim a garden hose, and you have access to unlimited clean water. You pay the occasional utility bill, or maybe that cost is built into your rent, and everything flows smoothly.

The downside of this convenience is that you may not be prepared for any disruption in your easy access to water. It could be something local: a household plumbing problem or a broken pipe on your street. It could be something regional and far more serious: an earthquake, a toxic spill near the water source, or rationing during a severe drought. So in the interest of disaster preparedness, keeping emergency water on hand is a smart thing to do.

And even when there’s no disaster, smart water use is good everyday policy for reducing your cost of living and consuming less of a precious shared resource.

How much emergency water do I need?

The U.S. Geological Survey (USGS) reports that the average adult human is about 60% water, and that three days is the median length of time we can survive without water. In case of emergency, the Department of Homeland Security (DHS) recommends a three-day minimum supply of one gallon (four liters) per household member per day. That may sound excessive, since few people drink a gallon of water on an average day, but factor in cooking, cleaning, and personal hygiene, and it starts making more sense. If your household includes children, nursing mothers, or people with health conditions, and if you live at a high altitude or in a hot climate, add another half gallon per person — at least. Does a neighbor rely on you? Are you caring for animals? You may need to store quite a bit of water after all.

How do I store my emergency water?

Small containers

For most households and in most situations, small containers are best. They’re easy to store, easy to fill with tap water, and easy to carry if you have to evacuate. The Federal Emergency Management Agency (FEMA) recommends storing your water in clean containers made of food-grade plastic (#1, #2, #4, and #7), glass, enameled metal, stainless steel, or fiberglass. A tight seal is critical for preventing evaporation and, more importantly, contamination. If you’re relying on stored water in an emergency, open only one container at a time to extend the usefulness of your supply. Date every container after filling it and open the older ones first.

For plastic containers, whether you filled them from your own tap or purchased distilled water in factory-sealed bottles, check your stock every six months for algae, bacterial growth, or chemical vapors that may leach out of or pass through the plastic. When your water looks or smells “off,” pour it on your plants, replace or thoroughly clean your containers, and start over again with fresh tap water.

Here are a few ideas for water storage containers:

If evacuating your home won’t be an issue, larger containers may be a better solution for storing emergency water onsite. The website Skilled Survival suggests a few options such as 55-gallon plastic drums, 35-gallon water kegs, short-term storage bladders designed for last-minute filling in sinks and bathtubs, and 3.5-gallon stackable water bricks. Here are some easily available water tanks:

Where do I store my emergency water?

Store your emergency water in a cool, dark place with no human or animal activity. Direct sunlight or heat increases the risk of biological growth and changes in chemistry, while excessive movement of the containers may loosen the seals and introduce bacteria. Think about the elaborate measures that wine collectors take when protecting their precious vintages, and apply similar care to your water supply!

What water storage mistakes should I avoid?

The flipside of any advice about how to store water is a warning about how NOT to store water.

  • Don’t use containers or tanks that haven’t been completely cleaned and disinfected (sterile is best).
  • Don’t fill your containers from an untrusted source.
  • Don’t use large containers without an appropriate pump or spout for easy access.
  • Don’t keep your water in open or unsealed containers that will leave it exposed it to bacteria, insects, or animals.
  • Don’t keep your water supply in a warm environment or in direct sunlight.
  • Don’t let stored water sit for longer than six months without testing it for potability — especially if you’re storing it a plastic container. (Factory-sealed, commercially-sold distilled water may have a longer shelf-life, but don’t take anything for granted.)

For more information, check out Skilled Survival.

How do I keep my emergency water supply potable?

Filling your containers from a trusted source is always a good first step. But does the water seem OK when you pour it out of the container? If you have any doubts, there are a few ways to purify your water: heating (boiling or distilling), adding chemicals (iodine or chlorine), filtering, and treating it with ultraviolet light. The Centers for Disease Control (CDC) provide a helpful page on emergency drinking water safety. (Consider printing this guide for times when you might be without electricity or online access.)


The CDC suggests these steps for purification by boiling.

If the water is cloudy:

  1. Filter it through a clean cloth, paper towel, or coffee filter, OR let it settle.
  2. Draw off the clear water.
  3. Bring the clear water to a rolling boil for one to three minutes.
  4. Let the boiled water cool.
  5. Store the boiled water in clean sanitized containers with tight covers.

If the water is clear:

  • Follow steps 3-5 above.

Distilling water means boiling it and collecting the steam in a clean container where it will turn back into water. You can improvise your own system or check out the commercially available options:


If you ever relied on a natural water source when camping or hiking, you may be familiar with iodine. Added to your water in solution, tablet, or crystal form, iodine kills most viruses and bacteria, which may be adequate for aged tap water. (The aftertaste can be unpleasant, though.)

If your original water source is untreated and you’re concerned about parasites such as Giardia (associated with cattle) or Cryptosporidium (carried by many kinds of wildlife), chlorine dioxide drops or tablets will be more effective. Maybe you’re thinking about household bleach and how extremely toxic it is, but instead think about accidentally swallowing swimming pool water. When the chlorine is under four parts per million (ppm), it’s safe for human consumption. If you’d rather not make this critical calculation, keep some chemical disinfectants with your emergency supplies:

Note that disinfectants are for biological contamination only. If your water has been chemically contaminated, iodine or chlorine won’t make it drinkable.


If you’re using a portable water filter to remove parasites, the CDC recommends a small filter pore size. Remember that filtering works best for visible particles. Very few portable filters can remove viruses or bacteria.

Ultraviolet light

If you like high-tech solutions for killing bacteria, consider ultraviolet light. This tool is essentially a battery-operated UV flashlight designed for stirring in a water container to neutralize microscopic life forms.

Smart, easy ways to conserve water

Along with preparing for emergencies, we can all be smarter about how we use one of our most precious shared resources. Much of our beautiful blue planet is covered with water, but with increasing environmental pollution and climate change uncertainty, protecting and transporting potable water becomes a much bigger challenge. This will be reflected in your utility bills at some point, so it’s worth strategizing about lowering your cost by lowering your use. Those of us in places like California are already familiar with drought conservation measures as well as the foreboding possibility of water rationing.

Any conservation effort starts small by adjusting personal habits.

Military showers

Turn off the water while you lather and scrub instead of letting it run continuously.

Catch your running water

If you need to run the water until it gets hot, put a big bowl or bucket under the tap and use it for something else, such as watering your plants (unless you have drought-tolerant landscaping) or bucket flushing your toilet.

Bucket flushing

Bucket flushing saves water and money whether you have a low-flush toilet that uses 1.6-3.5 gallons or an early-20th-century relic that requires 8 gallons.

Flush less

Best practice during droughts is flushing only when there’s solid waste in the bowl, which is a good way to be mindful about our casual daily water use.

Sustainable water conservation

It’s time to think about long-term sustainability in your home or business water use. Here are three ideas.

Rainwater harvesting

Rainwater is a free, relatively clean resource that’s available in great abundance depending on your local climate and weather. One inch of rainfall per square foot equals almost two-thirds of a gallon. The basic model for harvesting is a sloped roof, clean and robust gutters and drainpipes, and a barrel under the downspout. If you’re serious about collecting more water, consider these two catchment systems.

A “dry” system relies on gravity. The water enters the tank from the top, so the pipe is dry when there’s no rain. The disadvantage is that your tank must always be at the lowest point and therefore close to the building. A “wet” system relies on water pressure and fills from the bottom. While you have more options about where to place the tank, you’ll have to lay a lot of pipe, and that may require digging.

Here’s more about rainwater collection systems:

Is rainwater harvesting legal? Mostly. Only four U.S. states extensively restrict this practice (Colorado, Georgia, Oregon, Utah). Other states have few or no rules about rainwater use. Many encourage it, and five actually incentivize it (Delaware, Florida, New Jersey, Rhode Island, Virginia). World Water Reserve is a good resource for learning more about rainwater harvesting.

Gray water collection

Gray water refers to used water that isn’t sewage: drainage from sinks, bathtubs, showers, dishwashers, and clothes washers. It isn’t potable, but it can be used for flushing toilets and watering plants because its residue isn’t toxic to the environment or hazardous to human health. Gray water is easy to collect and reuse on a small scale — just fill a bucket to dump on or into something that needs it. (If you want to know why this is important for the environment, read this.) 

We can easily build ongoing gray waster reuse into our infrastructure. It just requires an alternate plumbing system with branched valves, filters, a surge tank, and a storage tank. The Tiny Life offers practical tips for building your own gray water system.

Learn more about gray water systems:


Many places on earth sit atop naturally occurring water that accumulates in the underground rocks, soil, and sand. According to, these aquifers provide drinking water for 51% of the total U.S. population and 99% of the rural population. Groundwater is a primary source for agriculture and industry, and it’s critical to the health of our lakes, rivers, and wetlands. Over 42 million U.S. homes and businesses rely on groundwater.

But that doesn’t mean everyone should start drilling for water in the backyard. Deep holes are a structural engineering challenge, filtration is important if you’re pumping out what could be essentially mud, and groundwater contamination is a real danger (your efforts might even be the cause of it). This is one project that you should leave to the hydrologists who understand your local water table and official regulations, and to the professional well contractors who know how to safely drill and pump.

Water is essential to our survival. Be smart about how you store and conserve it!

Alan Lipton, GreenCitizen's writer/editor, firmly believes in the company's mission to make every day Earth Day. His background in educational nonprofits, health literacy podcasts, experiential marketing, and storytelling helps him shape GreenCitizen's message. Alan also writes fiction and songs, performs music at farmers' markets and open mics, and battles unwanted vegetation in the yard.

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2 Comments on “Tips for How to Store (and Conserve) Water

    Thank you for reminding me to check our stock for any algae or bacterial growth to avoid exposing ourselves to unnecessary health risks. We get our supply from a water well, and there are times when it dries up so we really need to have our own stored supply. It might also be better to have someone check our systems and see if the dry season can be avoided.

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