Can We Drink Rain Water?

Water’s great right? Good for you, right? 

Rain is water, right?

Can We Drink Rain Water

We know what you’re thinking- put that cup away this instant.

Just because rain appears clear and falls from the heavens, does not mean that it is free of all the nasty contaminants and parasites that would otherwise be present in wild sources of water. 

As rain water falls through the air, it collects all manner of airborne particles and pollutants from that atmosphere, soaking them up like a sponge.

Rain water in cities is riddled with dust and chemicals.

Many nasty parasites, bacteria and viruses also survive being evaporated in the water cycle, raining down from us on high and potentially leading to disease if consumed- at the very least leading to a nasty stomach ache.

This is all considering that you actually captured this rain yourself too- if you’re drinking the rain run-off from a surface such as a roof then you’re also drinking all the bacteria from the bird muck and moss that ran off with it. Gross.

There are ways of making wild water safe to drink however, and in a survival situation, rainwater harvesting can be used along with water purification techniques to make safe, potable water.

Making Rain Water Safe To Drink


This is the simplest way to achieve purification. If you bring water to a full, rolling boil for over five minutes, you can kill any dangerous organisms in the liquid and drink it safely.

Allow it to cool before drinking it, and then pour it back and forth between two vessels to allow oxygen to re-enter the mixture and get rid of that unpleasant flat taste.

Purification Tablets/Solutions

These are chemicals that are available in tablets, although sometimes they come in drops. Iodine, chlorine, potassium permanganate, halazone etc. all work to kill organisms such as parasites and bacteria in wild water. 

Simply follow the instructions attached to the tablets, mixing the recommended amount into the water- which is typically only a small amount- and then wait until the solution has taken effect before drinking.

These solutions work quickly and should be done within minutes.

If you notice an unpleasant flavor following the purification, some people also carry around flavorings to add to the mixture.

In extreme survival situations, even a drop of bleach in a large amount of water has been used to help purify it.


You may use a water filter of some sort at home, but in a survival context there are other filters which help to make wild water potable and safe to consume for humans.

These filters pass the wild water through a mesh of charcoal or ceramic, and also apply a chemical treatment. 

This method leaves the flavor largely unaffected, and is one of the more thorough methods of getting water clean.

The downsides are how stringent you must be with avoiding cross-contamination of the different components, and that the filter must eventually be replaced to continue operating; these can be purchased from camping stores and should also be brought with you in a survival situation.

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Collecting Rain Water For Gardening

The presence of contaminants in rainwater does not mean that captured rainwater has no use!

Plants actually prefer the ‘soft’ nature of mineral water, compared to the ‘hard water’ of a human water supply, as it has a lower pH which has a positive effect on nutrient availability.

With climate change and denser populations having an impact on the stability of water supplies during the warmer months, many gardeners have begun tapping into the ancient practice of collecting rainwater for year-round use on their vegetables and plants.

Water is especially important to living things when the weather is hot and dry- which is of course, just when there is even less water to go around.

It’s also a simple fact that water shortages and hosepipe bans due to an excess of demand vs. supply can devastate the health of some more delicate plants you may have put a lot of effort into cultivating; shrubs, seedlings, herbaceous perennials and vegetables all require careful watering, and one bad heatwave can spell the end.

Minimizing Risk From Collected Rainwater

Collected rainwater for gardening is not clean for hygiene use nor safe to drink, but it is an optimal breeding ground for many other forms of life- especially once it becomes a sitting body of water. 

Nasty bacteria such as legionella and parasitic insect larvae such as mosquitoes will thrive in warm, still bodies of water- which includes many water butts.

To reduce the risk of harming yourself when using the rainwater from a water drum, you must adhere to the following steps:

  • Keep the drum in a shaded area, preferably one that receives around-the-clock shade.
  • This will keep the water in the drum cool and less pleasant for bacteria and insects to breed in.
  • Keep the elements of your water collection system free from debris, as this will encourage bacteria.
  • Use a watering can with your water drum: Fine sprays will aerosolize the sitting water from the drum, which can be easily breathed-in.
  • Wash your hands after using the water drum in any manner.
  • Use the water drum constantly so that a rotation of fresh rainwater dilutes its contents. Empty and clean the barrel once a year.
  • Smelly water implies a build up of debris and the flourishing of bacteria. Empty and clean the drum and guttering without chemicals, as this can simply mask the odor without solving the root cause.
  • Disconnect the hoses attached when not in use to discourage the growth of bacteria. Always allow them to fully drain.
  • Cover your barrels so that they present no falling-in risks to small children or animals, and then seal them well so that they don’t become insect breeding grounds.
Mike Noren