How to Collect Rainwater with Just the Shirt off Your Back

Plus other simple moisture catchment methods that could save your life.

You’ve got emergency food. You’ve got a backup water supply.  But it’s not enough.

You need to know how to obtain these resources when they run out… or are taken out. 

That’s why today we’re covering one of the most important topics in all emergency and outdoor survival: how to harvest rain when your water supply is compromised.

Priority 1: You Need Rain

It goes without saying that all of this advice relies on being in an environment that gets regular rain. In a place with lots of daily rain, you may not even need the tactics we’re about to cover. But if you find yourself in a drier environment with occasional rain, every droplet can count, and rain catchment techniques can save your life.

“Shirt-Off-Your Back” Water Catchment

In the absence of anything else, the shirt you’re wearing can be a great tool for collecting moisture. Pants will work too, though depending on your environment it may not be advisable to strip down completely. Use your judgement.

One thing to keep in mind is the material you’re working with. If you ever find yourself in the position of having to choose between which articles of clothing to use for water catchment, keep this in mind:

1. Cotton is the best material for absorbing water. It’s also great at releasing most of its water when you ring it out. In other words, always go with the t-shirt on your back if you have the option.
2. Denim, which is made of cotton, is another good bet, though because of the nature of the fiber it isn’t going to absorb as well as a t-shirt.
3. Polyester absorbs better than you might think. It can both retain and expel water and is acceptable if you’re lacking cotton.
4. Polyester blends aren’t quite as good at catchment as plain polyester. Depending on the fabrics, they either struggle to retain water or to expel it.

Once you’ve got your article of clothing selected (we’ll assume it’s a t-shirt for the sake of this explanation), here are a couple of the most effective methods for using it to collect water:

Morning Dew – Roll up your shirt, tie it around an ankle and walk through tall grass in the early morning hours (or through foliage if you can’t find grass). The shirt will collect dew from the vegetation around you.

Walk till the shirt is thoroughly soaked, then remove it and ring it out over a wide mouthed water bottle, pot, or bowl—just be very careful not to spill any.

Ring Out Your Shirt – Here’s another way you can take advantage of your shirt’s absorbance to collect water. If it’s raining, remove your shirt and place it in an elevated spot where it’s less likely to pick up dirt and debris. The branches of a tree will work, as will the top of a tent, car, or rocks.

Primitive Rain Catchment Methods

Along with fabric catchment, here are some other basic methods of rainwater retrieval:

Tree Joints – Our ancestors used the topography of the land to collect rainwater, and there’s no reason we can’t do the same. If you’re in an area with large trees, it shouldn’t be too hard to find puddles of moisture collected between forking branches.

Rock Crevices – Large rocks and boulders are also great catchment sites. If you can safely get yourself within reach of a large one, you can collect enough water to fill your needs for at least a day. 

The Most Effective Low-Budget Catchment Method

Tarp Trap – If you’re able to plan ahead, one of the best-known water catchment techniques requires a tarp (a tent or mylar blanket will work too), some rope, and as many buckets, pots, cups, etc., as you can get. There are a few ways to build your water trap, but generally you should:

1. Spread out the tarp completely.
2. Secure the four corners of the tarp (by the eyelets) to tree branches, sticks pounded into the ground, the bed of a truck etc.
3. The positioning of the tarp might be the most important thing. One end should be elevated and taut. The other end should rest a bit lower and have some slack.
4. With the tarp unfurled and secured, tie a piece of rope through the center-front grommet on the lower-elevated side.
5. Tie a rock of about six inches to one foot in length to the free end of the rope.
6. Place the rock, tied to the rope, into your collection vessel.
7. Wait for rain!

To see this method in action, check out this awesome video. For a slightly more “primitive” version, click here.

BONUS! Simple Water Catchment Technique, No Rain Needed

This old trick is best used in spring and summer when it’s sunny and moist out. With a clear plastic bag (no holes) and some rope, rubber band, string, or paracord, you’ve got everything you need to collect water from a tree. Here’s how:

1. Open the plastic bag and envelop a branch (or a few depending on the tree’s size) into the bag.
2. Wrap the opening of the plastic bag shut.
3. Tie the rope, rubber band, string, or paracord around the “wrapped” portion of the plastic bag to keep it shut.
4. Leave the bag in the sun for about a day
5. Come back and collect your water. Be prepared—you won’t be gathering gallons worth, but the little you do produce can provide enough to survive in a life-or-death situation.

Words of Warning!

After going to all the effort to collect water, the last thing you want is to expel it from your body because it was contaminated. That’s why, whenever you go hiking or camping or pack a go-bag, you need to include a good, portable water filter.

For mobility, we recommend the Survival Spring Filter by Alexapure. It’s our favorite portable filter (which is why we’ve chosen to sell it on our site). It’s a straw that’s perfect for water catchment applications—just bend down and use it to drink from a rock crevice, bucket, tarp, etc. It’s also great for large bodies of water like lakes, rivers and streams. It purifies 99% of waterborne protozoa and bacteria. It will keep the water inside your body (where it belongs).

Works Cited

https://verber.com/mark/outdoors/gear/clothing-waterabsorption.html

https://cs.appstate.edu/~rt/SummerVentures/2012/papers/VyomJosh.pdf

https://blog.survivalfrog.com/extract-water-tree/

https://www.outdoorlife.com/photos/gallery/hunting/2012/02/essential-knots-how-tie-20-knots-will-keep-you-alive/

https://blog.survivalfrog.com/extract-water-tree/

http://trailmob.com/outdoor-skills/how-to-collect-drinking-water-from-dew/