How to Quickly and Safely Collect Rainwater for Use in Survival
Collecting Water for Survival
On November 14th, 1992, Vietnam Airlines Flight 474 crashed into a mountain en route from Ho Chi Minh City to the Vietnamese coastal city of Nha Trang. Annette Herfkens, a 31-year-old banker and her fiancee, 36-year-old Willem van der Pas, were among the 30 people on board. However, Herfkens would be only one of two people to survive the initial crash — and then the only person to survive the jungle conditions around her.
After the crash, Herfkens woke up from a blackout state. She found a piece of bone sticking out of one of her legs. She wasn’t aware of it at the time, but her hips were fractured, her jaw was dislocated, and one of her lungs had collapsed. She noticed that her fiancee and everyone else aboard the plane was dead, except for another passenger, a Vietnamese man. He spoke to her, and somehow helped recover some clothes for her. But he was too weak to stay conscious, and died a few hours later.
Herfkens was initially in shock, but after some time, she crawled around on her elbows to other parts of the plane wreckage. She fashioned some sponges out of the airplane’s wing insulation. Using this, and a recovered poncho to stay dry, she collected the rainwater she needed to survive.
After seven days, a local police officer spotted her and ran for help. Authorities had been searching for survivors. Herfkens was airlifted to Ho Chi Minh City and was later transferred to a Singapore hospital. She would soon see her family and friends. She had made it.
Collecting Rainwater to Survive
Chances are, you won’t find yourself in a situation as extreme as Annette Herfkens did. But if you’re interested in emergency survival preparedness, you should know how to go about quickly and safely collecting water, especially rainwater.
A person can survive more than three weeks without food, but at most about 3 days without water. If you factor in actual environmental variables like dryness or heat, your survival duration without water can be even less then three days.
Ideally, collecting water — specifically rainwater — should involve a few things:
- Finding a method to quickly collect the rainwater. A tarp, barrel, or sponge can be used.
- Finding a way to keep the water clean for storage. Mesh and sealing methods are ideal for this.
- Finding a way to purify the water, including boiling, chemical treatments, and commercial water filters.
- Finding an ideal way to store the water for future use.
This article will focus on quick and safe ways in collecting water, especially rainwater, for emergency preparedness and survival purposes.
Methods of Collecting Rainwater
There are several ways to go about collecting water for emergency preparedness. These include:
- Sponges,
- Barrels,
- Tarps, and
- Other containers, such as jars, bottles, or buckets.
Sponges
Herfkens used airplane insulation as a sponge, but really only as the emergency situation required. You are almost guaranteed to quickly collect rainwater with a sponge so long as it sits out in the rain. But it really is not good for collecting large amounts of water, at most a few drops at a time.
Barrels
A somewhat more durable solution to collecting water is to use a barrel. You definitely can collect more rainwater at a time, and it is likely to stay stored well, too.
However, you have to make sure that the barrel itself is clean, that there are no leaks, that there is nothing (like branches or leaves) hanging over the barrel, and that there is a fine mesh to keep dirt, insects, and other animals out.
Tarps
For a more careful emergency preparedness approach, you may want to use a tarp. Made of durable canvas, polyurethane, or polyethylene, tarps are often used for camping and shelter. They are also one of the quickest ways to secure large amounts of rainwater.
If you place a tarp over an existing structure like a garden shed and fold it properly, you can put barrels or buckets around the four corners where the water is likely to go. Then, the water can flow off the structure, directly into the containers.
You can also do the inverse — using four posts or tent poles. Tie the four tarp corners to the poles or high posts and hang the tarp so it collects water in the middle. Or, put two corners of the tarp on two higher poles and the two opposite corners on two lower poles. This way, you can direct the water down into a container like a barrel or bucket.
Finally, you can dig a large, deep, hole in the ground and put a container in the middle of the hole. Then, stretch a tarp over the hole and secure the corners of the tarp with rocks, so that the tarp hangs down slightly over the container.
You can place a rock in the center of the tarp (over the hole) so that it sags further. The idea is to create a condensation trap, or a solar still, to get the existing rainwater out of the surrounding soil and beaded up on the underside of the tarp. The water then drops into the container.
Other containers
You can use other containers for collecting water, such as jars, bottles, buckets, or even small boats. The problem however, is getting sufficient amounts of water and managing to keep the water clean.
Stagnant water in such containers can result in fly and mosquito larvae, and can be a breeding ground for parasites and bacteria. You will also want to have the container secured, so it does not blow over in the wind. Make sure you have a stable base, and enough netting and covering to keep these containers grounded, protected, and clean.
Keeping rainwater clean
As mentioned before, you will want to keep the rainwater clean during collection. A good way to do this is with fine mesh or form-fitting lids. Place these over the top of any container you wish to use, and your water will remain clean and safe.
Purifying rainwater
There are four ways to purify rainwater you’ve collected. It is recommended you use as many as these methods as you possibly can:
- Filtering
- Boiling
- Chemical Treatment
- Commercial Water Filters
Filtering
As per the United States’ Centers for Disease Control and Prevention (CDC), you will want to filter cloudy or otherwise dirty water through clean cloth or clothes before getting your water ready to boil. Filter the water into a clean container and take the cleanest water off the top.
Boiling
Also per the CDC, it is recommended that after filtering, you boil the water for at least one minute (three minutes in higher altitudes) in a rolling boil.
A pinch of salt for each quart of water can improve flavor. Boiling will usually kill off most organisms that live in the water. Let the water cool to room temperature and transfer to a clean container.
Chemical treatment
If boiling is not an option (it should be, though), the CDC says you may want to use chemical treatment. After filtering water with clean cloths and taking the cleanest water off the top, stir in 1/8 of a teaspoon of clear, unscented, household bleach per gallon of water and let it stand for at least 30 minutes. Store in clean containers with covers.
You can also use iodine to treat water — but, as always, consult with the CDC website first. Iodine treatment is not recommended for pregnant women or those with thyroid conditions, and it is not recommended to use iodine for more than several weeks at a time.
Commercial water filters
If nothing else, filter and boil your water first. Commercial water filters are not a substitute for filtering, boiling or chemical treatments. But they can be used in addition to these methods.
Make sure that your filter pore sizes are less than 1 micron across in order to filter out most organisms and bacteria. Filter types include membrane, carbon, and ceramic.
Storing water for future use
If you are done collecting water and cleaning it, you will want to be able to store it.
If you are in the initial stages of collecting water, you will want to use clean containers. Also, use containers that are light-proof, meaning they are not conducive to growing algae or moss. Cover them with netting to keep mosquitoes and other insects out. Retrieve your water in a timely fashion (ideally, right after it has rained) to keep your water from getting stagnant.
Finally, after purification (filtering and boiling), use clean containers with covers. Use some common sense as well. If your water has not been used in a few hours, days, or weeks, you may want to filter and boil it again. You want to be able to use the rainwater you collect — in case of any emergency.
Sources
https://en.wikipedia.org/wiki/Annette_Herfkens
https://www.businessinsider.com/how-many-days-can-you-survive-without-water-2014-5
Camping and Wilderness Survival: The Ultimate Outdoors Book by Paul Tawrell, page 473: https://books.google.com/books/about/Camping_and_Wilderness_Survival.html?id=H2ZtOgAACAAJ
https://secretsofsurvival.com/rainwater-harvesting/
https://homeguides.sfgate.com/can-water-collected-rain-barrel-purified-drink-78356.html
https://en.wikipedia.org/wiki/Tarpaulin
https://en.wikipedia.org/wiki/Solar_still
https://www.cdc.gov/healthywater/drinking/travel/emergency_disinfection.html
https://wwwnc.cdc.gov/travel/yellowbook/2020/preparing-international-travelers/water-disinfection
